89 2.5L Surge at a steady Idle

popo09 · 10-15-2009, 06:15 PM

title should have been steady throttle not idle

Ok guys im new to the forum but not new to the 2.5L as I have been trying to figure out what is wrong with mine. At a steady throttle around 30-40 mph it surges bucks misses whatever u wanna call it. I have replaced so many parts here is the list some that may not have any thing to do with the problem but Ill list them anyways. Rear main, clutch, flywheel, cap, rotor button, plugs, wires, Ignition module, fuel pump relay, fuel pressure regulator, supposidly it had a new fuel pump put in it before i got the truck, deleted the egr and have a block off plate i made. Now it doesnt surge all the time, just every now and then... if you give it throttle it stops, if you let off it stops.. just at a steady throttle it does it. So if anyone has any ideas please help!

Steady Eddie · 10-15-2009, 07:43 PM

popo--

The brainbox looks for a lean-out condition at 40 MPH, to "test" the EGR valve. Sooner or later, with the EGR valve gone, or disconnected, it will turn on the SES light and set a code. Has yours done that??

popo09 · 10-15-2009, 07:57 PM

No it hasn't set a light yet and the said condition was there before deleting the egr. So I assume the egr was not the problem.

Steady Eddie · 10-15-2009, 09:51 PM

Map ??

popo09 · 10-15-2009, 09:59 PM

Quote: Originally Posted by Steady Eddie

Map ??

Unplugged all sensors one at a time and held the throttle at a steady idle and it still had a miss.

Steady Eddie · 10-16-2009, 12:46 AM

???maybe something mechanical, a burnt valve??

popo09 · 10-16-2009, 08:41 AM

doesnt use any oil, burn any oil or any odd noises runs like a top other than the studder every once in awhile.. So Im pretty sure the insides are good..im sure if it was a burnt valve you would hear noise and or performance would suffer.....

lesterl · 10-16-2009, 06:07 PM

Checked fuel pressure? Could be a bad pump, even tho you said it was new cheap pumps do crap out easily.

popo09 · 10-17-2009, 11:56 PM

ok fuel pressure good, replaced pick up coil, hall effect switch, coil, still no change. My buddy and I did notcie that the exhaust was kinda coming out slow..new exhaust from cat back about 2-3 months ago. Cat is the original one.. ok Maybe the cat is clogged and or clogging the whole exhaust..pull the little plug outta the bottom and all the bbs go flying.. truck runs even worse.. put the plug back in and still no change.. how can it run worse it has every sensor on it replaced.. had the map sensor checked at the zone.. tested out good..so im at a loss now! gonna cut the cat off and hope thats the problem.. too much backpressure? anyone help is very appreciated.. I have no where else to go other than the cat. oh and we put a new injector in it too! and threw a nod tester on the injector plug.. guess what good.. so the computer is good plus i found out today it has a new one in it! so... anyone?

lesterl · 10-18-2009, 10:29 PM

How much fuel pressure did you have?

What exactly is it doing worse now, the surge at idle?

Have you tested the TPS? Has it been set up properly?

Vacume Leaks?

popo09 · 10-20-2009, 08:53 PM

ok tested fuel pressure! 12psi what is it supposed to be? and for the hell of it done a compression test. cylinder 1= 105psi cylinder 2= 110psi cylinder 3=95psi and cylinder 4= 95psi...
so what do these numbers tell me?

popo09 · 10-20-2009, 08:59 PM

oh and plugs are showing way lean! could it be that small rubber hose that goes from the pump to the sending unit?

popo09 · 10-20-2009, 09:56 PM

come on guys any help?

lesterl · 10-20-2009, 11:21 PM

Fuel pressure ok, compression #'s are kinda low.....

How do the plugs look (color).

91MNS10 · 10-21-2009, 01:11 AM

My 91 was just doing the exact same thing and it was the o2 sensor.

popo09 · 10-21-2009, 07:44 AM

Plugs showed way lean. I all ready stated that above! I put a new O2 in it! All ready stated that above too!

popo09 · 10-21-2009, 07:59 PM

Well going to do a leak down test and pull the bed of check to male sure that rubber hose is in good shape. I can run the truck 10 -15 miles an check the radiator cap and it's cold! Any ideas on that? Brand new thermostat put in it last week. Maybe it's not working? So fuel pressure is good! But what explains the lean plugs? There's too many new parts on this thing for it to act like this! Does anyone have a clue? Other than anything allready mentioned and anything that I have said I've done

rideharder · 10-22-2009, 09:37 PM

ok well i had the same problem with mine. do you have a erg valve in it right now or did you block it off. if you just blocked it off it will make the truck run lean unless you buy a chip for the computer. with my truck i had the exact same situation.... checked everything. all it turned out to be was the egr valve, carbon buildup and had a small leak. be sure you buy the right egr valve too, there are 2 diffrent ones and only one will work on one type of engine. i replaced the egr and all problems were gone.

Shaddix · 10-24-2009, 01:19 PM

Their is no way you can delete the EGR valve with a blockoff plate and expect it to work perfectly. Somehow, you need to get that EGR system hooked back up properly. It will never run right with a blockoff plate, as these ECU's use the EGR valve a lot. I need a minimum of PREMIUM gas to keep the detonation down, which is still present, burning away my exhaust valves on LONG hills! A lot of people run them with the EGR unhooked, but it will not run as good as it did when it was new and you WILL burn valves!

Steady Eddie · 10-25-2009, 12:27 PM

popo--

See post 18 above...

popo09 · 10-25-2009, 07:14 PM

well put a new fuel pump in it after inspection of the old one.. hose that connects the sender to the pump was very mushy..new pump in still does it! i did put the egr back on and it still does it! i think i might have a burnt exhaust valve! sound like it? low compression on the back two cylinders! not as much exhaust coming out of the tail pipe as I would like to see.. so does this maybe sound like a likely scenario? i also have the throttle body off torn completely apart and soaking in that chem stuff.. any ideas? where can i find valves for these things?

Steady Eddie · 10-25-2009, 07:53 PM

popo--

You are grasping at straws...I suspect that you re-installed a flaky EGR valve, one that was nipples to the sky, to begin with.

It is very easy to get in over your head, with these little motors.

Believe me, the money is better spent on wine, women, and song...

DO NOT tear into it any farther than you have to.

My '89 had a significant increase in measured compression, and power, after the second oil change, when I went with full Syn 10W-30 wt. oil.

I figure the rings were gummed up.

Sure, it'll be better with a fresh valve grind, but don't spend the cash, if you don't have to...try the cheaper alternatives, first.

lesterl · 10-25-2009, 11:03 PM

Could be a Head Gasket, or could be as Eddie suggests and the rings are stuck, try seafoaming the hell outt 'er. If it is valves, you could get some grinding solution and do it yourself....

popo09 · 10-26-2009, 09:10 PM

I have sea foamed it! lol.. just put the throttle body back on with all new fresh gaskets.. guess what still does it! Steadit Eddie, it had this problem even with the egr off of it! do you really think an egr valve could reak this much havic? I mean look at all the parts Ive put into this thing and nothing is getting better! If anything it getting worse! I have no where else to go but internally! any other ideas? lol

lesterl · 10-26-2009, 09:53 PM

I guess I will ask again, what coloration were the plugs.... What do you consider lean?

popo09 · 10-26-2009, 11:02 PM

they are showing lean....i have a new set that i was gonna put in but i dont wanna waste them ya know. they dont look like a brown paper sack. I need to do a compression check again. I didnt pull all the plugs last time i did it! so with cylinder 3 and 4 both reading 95psi I suspect a blown head gasket between them two. If its blown there then those two cylinders could be working together and giving me the same reading! right? so by pulling the plugs and doing it that way I should get a very low reading from those two cylinders!

Steady Eddie · 10-27-2009, 10:18 AM

Quote: Originally Posted by popo09

"...do you really think an egr valve could wreak this much havoc?..."

=========================
popo--

Short answer: Yes....

popo09 · 10-28-2009, 01:30 PM

Well I haven't done the compression test again yet, but I feel like explaining more what this thing is doing. When u give it more than 1/4 throttle it boggs out and ocasionally it will backfire through the thirttle body.

Shaddix · 10-28-2009, 02:13 PM

DON NOT trust an old EGR valve. Do as Steady Eddie suggested and replace it. You may have installed a leaky EGR back onto it. These EGR's do wreck havoc on the 2.5L and need to be working 100%. You cant eliminate the EGR valve until a correct BRAND NEW AC Delco/Delphi valve (auto or manual) is installed. Even an old cleaned valve may or may NOT work.

Please post back if you have a new valve to try out.

popo09 · 10-28-2009, 04:16 PM

No did not install a new egr. How do you suspect that it's causing it to be a balles wonder after more than 1/4 throttle? I'll do the compression test again and see if that turns up any new evidence.

Shaddix · 10-28-2009, 08:53 PM

Quote: Originally Posted by popo09

No did not install a new egr. How do you suspect that it's causing it to be a balles wonder after more than 1/4 throttle? I'll do the compression test again and see if that turns up any new evidence.

Well, these EGR's are a nightmare. Some work, most dont. I am assuming that you have already checked your TPS sensor first and got a smooth sweep of voltage, and also am assuming that you CTS sensor has been spec'ed out with an ohm meter at different temps to make sure its OK. I dont know how to check the MAP, but if its not those, then I would go EGR next.

popo09 · 10-29-2009, 08:38 PM

Just checked the compression again with all the plugs out like your supposed to do and it checks out. 135 125 125 and 125psi. So no blown head gasket here. Going to pop the valve cover and check the cam timing by checking the lifters on the compression stroke of each cylinder.

popo09 · 11-01-2009, 07:49 PM

i meant check the cam lift.. seeing if it had a swiped cam lobe and no it doesnt! put the valve cover back on and come to find out it was out of time! So put it in time and it barks second gear now lol.., but it still has the surge that it had when this all started! u can actually look at the injector firing in the tb and see it pulse! so does that point to the computer? anyone have any suggestions?

Shaddix · 11-02-2009, 12:04 PM

Quote: Originally Posted by popo09

i meant check the cam lift.. seeing if it had a swiped cam lobe and no it doesnt! put the valve cover back on and come to find out it was out of time! So put it in time and it barks second gear now lol.., but it still has the surge that it had when this all started! u can actually look at the injector firing in the tb and see it pulse! so does that point to the computer? anyone have any suggestions?

The surge you are feeling, most likley, is the computer looking for the EGR system. You have deleted it on your ride, and the computer is severely leaning out the fuel mixture. The only way to fix it because of your blockoff plate, is to call Sinister Performance and get a custom chip for $55. They remove the EGR function alltogether, and it seems like its the only way to go.

I did read that you tried installing an old valve, but I did the same and mine isnt working either. Did you put the solenoid back on and both vacuum lines?

10-15-2009, 06:15 PM	#1
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	89 2.5L Surge at a steady Idle title should have been steady throttle not idle Ok guys im new to the forum but not new to the 2.5L as I have been trying to figure out what is wrong with mine. At a steady throttle around 30-40 mph it surges bucks misses whatever u wanna call it. I have replaced so many parts here is the list some that may not have any thing to do with the problem but Ill list them anyways. Rear main, clutch, flywheel, cap, rotor button, plugs, wires, Ignition module, fuel pump relay, fuel pressure regulator, supposidly it had a new fuel pump put in it before i got the truck, deleted the egr and have a block off plate i made. Now it doesnt surge all the time, just every now and then... if you give it throttle it stops, if you let off it stops.. just at a steady throttle it does it. So if anyone has any ideas please help! Last edited by popo09 : 10-15-2009 at 06:21 PM.
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10-15-2009, 07:43 PM	#2
Steady Eddie Sending Big Oil a Message Join Date: Mar 2008 Posts: 1,009 Location: The Great Pacific Northwet User is: OffLine	Re: 89 2.5L Surge at a steady Idle popo-- The brainbox looks for a lean-out condition at 40 MPH, to "test" the EGR valve. Sooner or later, with the EGR valve gone, or disconnected, it will turn on the SES light and set a code. Has yours done that??
	[Reply w/Quote]

10-15-2009, 07:57 PM	#3
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle No it hasn't set a light yet and the said condition was there before deleting the egr. So I assume the egr was not the problem.
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10-15-2009, 09:51 PM	#4
Steady Eddie Sending Big Oil a Message Join Date: Mar 2008 Posts: 1,009 Location: The Great Pacific Northwet User is: OffLine	Re: 89 2.5L Surge at a steady Idle Map ?? Last edited by Steady Eddie : 10-15-2009 at 09:55 PM.
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10-15-2009, 09:59 PM	#5
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle Quote: Originally Posted by Steady Eddie Map ?? Unplugged all sensors one at a time and held the throttle at a steady idle and it still had a miss.
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10-16-2009, 12:46 AM	#6
Steady Eddie Sending Big Oil a Message Join Date: Mar 2008 Posts: 1,009 Location: The Great Pacific Northwet User is: OffLine	Re: 89 2.5L Surge at a steady Idle ???maybe something mechanical, a burnt valve??
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10-16-2009, 08:41 AM	#7
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle doesnt use any oil, burn any oil or any odd noises runs like a top other than the studder every once in awhile.. So Im pretty sure the insides are good..im sure if it was a burnt valve you would hear noise and or performance would suffer.....
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10-16-2009, 06:07 PM	#8
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,402 Location: Harrisonville, MO User is: OffLine	Re: 89 2.5L Surge at a steady Idle Checked fuel pressure? Could be a bad pump, even tho you said it was new cheap pumps do crap out easily.
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10-17-2009, 11:56 PM	#9
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle ok fuel pressure good, replaced pick up coil, hall effect switch, coil, still no change. My buddy and I did notcie that the exhaust was kinda coming out slow..new exhaust from cat back about 2-3 months ago. Cat is the original one.. ok Maybe the cat is clogged and or clogging the whole exhaust..pull the little plug outta the bottom and all the bbs go flying.. truck runs even worse.. put the plug back in and still no change.. how can it run worse it has every sensor on it replaced.. had the map sensor checked at the zone.. tested out good..so im at a loss now! gonna cut the cat off and hope thats the problem.. too much backpressure? anyone help is very appreciated.. I have no where else to go other than the cat. oh and we put a new injector in it too! and threw a nod tester on the injector plug.. guess what good.. so the computer is good plus i found out today it has a new one in it! so... anyone?
	[Reply w/Quote]

10-18-2009, 10:29 PM	#10
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,402 Location: Harrisonville, MO User is: OffLine	Re: 89 2.5L Surge at a steady Idle How much fuel pressure did you have? What exactly is it doing worse now, the surge at idle? Have you tested the TPS? Has it been set up properly? Vacume Leaks?
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10-20-2009, 08:53 PM	#11
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle ok tested fuel pressure! 12psi what is it supposed to be? and for the hell of it done a compression test. cylinder 1= 105psi cylinder 2= 110psi cylinder 3=95psi and cylinder 4= 95psi... so what do these numbers tell me?
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10-20-2009, 08:59 PM	#12
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle oh and plugs are showing way lean! could it be that small rubber hose that goes from the pump to the sending unit?
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10-20-2009, 09:56 PM	#13
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle come on guys any help?
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10-20-2009, 11:21 PM	#14
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,402 Location: Harrisonville, MO User is: OffLine	Re: 89 2.5L Surge at a steady Idle Fuel pressure ok, compression #'s are kinda low..... How do the plugs look (color).
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10-21-2009, 01:11 AM	#15
91MNS10 Registered User Age: 32 Join Date: Apr 2009 Posts: 24 Location: Winsted, MN User is: OffLine	Re: 89 2.5L Surge at a steady Idle My 91 was just doing the exact same thing and it was the o2 sensor.
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10-21-2009, 07:44 AM	#16
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle Plugs showed way lean. I all ready stated that above! I put a new O2 in it! All ready stated that above too!
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10-21-2009, 07:59 PM	#17
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle Well going to do a leak down test and pull the bed of check to male sure that rubber hose is in good shape. I can run the truck 10 -15 miles an check the radiator cap and it's cold! Any ideas on that? Brand new thermostat put in it last week. Maybe it's not working? So fuel pressure is good! But what explains the lean plugs? There's too many new parts on this thing for it to act like this! Does anyone have a clue? Other than anything allready mentioned and anything that I have said I've done
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10-22-2009, 09:37 PM	#18
rideharder Registered User Age: 19 Join Date: Nov 2008 Posts: 58 Location: Vernon B.C. User is: OffLine	Re: 89 2.5L Surge at a steady Idle ok well i had the same problem with mine. do you have a erg valve in it right now or did you block it off. if you just blocked it off it will make the truck run lean unless you buy a chip for the computer. with my truck i had the exact same situation.... checked everything. all it turned out to be was the egr valve, carbon buildup and had a small leak. be sure you buy the right egr valve too, there are 2 diffrent ones and only one will work on one type of engine. i replaced the egr and all problems were gone.
	[Reply w/Quote]

10-24-2009, 01:19 PM	#19
Shaddix Registered User Join Date: Apr 2003 Posts: 144 Location: Astoria, Oregon User is: OffLine	Re: 89 2.5L Surge at a steady Idle Their is no way you can delete the EGR valve with a blockoff plate and expect it to work perfectly. Somehow, you need to get that EGR system hooked back up properly. It will never run right with a blockoff plate, as these ECU's use the EGR valve a lot. I need a minimum of PREMIUM gas to keep the detonation down, which is still present, burning away my exhaust valves on LONG hills! A lot of people run them with the EGR unhooked, but it will not run as good as it did when it was new and you WILL burn valves!
	[Reply w/Quote]

10-25-2009, 12:27 PM	#20
Steady Eddie Sending Big Oil a Message Join Date: Mar 2008 Posts: 1,009 Location: The Great Pacific Northwet User is: OffLine	Re: 89 2.5L Surge at a steady Idle popo-- See post 18 above...
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10-25-2009, 07:14 PM	#21
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle well put a new fuel pump in it after inspection of the old one.. hose that connects the sender to the pump was very mushy..new pump in still does it! i did put the egr back on and it still does it! i think i might have a burnt exhaust valve! sound like it? low compression on the back two cylinders! not as much exhaust coming out of the tail pipe as I would like to see.. so does this maybe sound like a likely scenario? i also have the throttle body off torn completely apart and soaking in that chem stuff.. any ideas? where can i find valves for these things?
	[Reply w/Quote]

10-25-2009, 07:53 PM	#22
Steady Eddie Sending Big Oil a Message Join Date: Mar 2008 Posts: 1,009 Location: The Great Pacific Northwet User is: OffLine	Re: 89 2.5L Surge at a steady Idle popo-- You are grasping at straws...I suspect that you re-installed a flaky EGR valve, one that was nipples to the sky, to begin with. It is very easy to get in over your head, with these little motors. Believe me, the money is better spent on wine, women, and song... DO NOT tear into it any farther than you have to. My '89 had a significant increase in measured compression, and power, after the second oil change, when I went with full Syn 10W-30 wt. oil. I figure the rings were gummed up. Sure, it'll be better with a fresh valve grind, but don't spend the cash, if you don't have to...try the cheaper alternatives, first. Last edited by Steady Eddie : 10-25-2009 at 08:01 PM.
	[Reply w/Quote]

10-25-2009, 11:03 PM	#23
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,402 Location: Harrisonville, MO User is: OffLine	Re: 89 2.5L Surge at a steady Idle Could be a Head Gasket, or could be as Eddie suggests and the rings are stuck, try seafoaming the hell outt 'er. If it is valves, you could get some grinding solution and do it yourself.... Last edited by lesterl : 10-25-2009 at 11:06 PM.
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10-26-2009, 09:10 PM	#24
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle I have sea foamed it! lol.. just put the throttle body back on with all new fresh gaskets.. guess what still does it! Steadit Eddie, it had this problem even with the egr off of it! do you really think an egr valve could reak this much havic? I mean look at all the parts Ive put into this thing and nothing is getting better! If anything it getting worse! I have no where else to go but internally! any other ideas? lol
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10-26-2009, 09:53 PM	#25
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,402 Location: Harrisonville, MO User is: OffLine	Re: 89 2.5L Surge at a steady Idle I guess I will ask again, what coloration were the plugs.... What do you consider lean?
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10-26-2009, 11:02 PM	#26
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle they are showing lean....i have a new set that i was gonna put in but i dont wanna waste them ya know. they dont look like a brown paper sack. I need to do a compression check again. I didnt pull all the plugs last time i did it! so with cylinder 3 and 4 both reading 95psi I suspect a blown head gasket between them two. If its blown there then those two cylinders could be working together and giving me the same reading! right? so by pulling the plugs and doing it that way I should get a very low reading from those two cylinders!
	[Reply w/Quote]

10-27-2009, 10:18 AM	#27
Steady Eddie Sending Big Oil a Message Join Date: Mar 2008 Posts: 1,009 Location: The Great Pacific Northwet User is: OffLine	Re: 89 2.5L Surge at a steady Idle Quote: Originally Posted by popo09 "...do you really think an egr valve could wreak this much havoc?..." ========================= popo-- Short answer: Yes....
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10-28-2009, 01:30 PM	#28
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle Well I haven't done the compression test again yet, but I feel like explaining more what this thing is doing. When u give it more than 1/4 throttle it boggs out and ocasionally it will backfire through the thirttle body.
	[Reply w/Quote]

10-28-2009, 02:13 PM	#29
Shaddix Registered User Join Date: Apr 2003 Posts: 144 Location: Astoria, Oregon User is: OffLine	Re: 89 2.5L Surge at a steady Idle DON NOT trust an old EGR valve. Do as Steady Eddie suggested and replace it. You may have installed a leaky EGR back onto it. These EGR's do wreck havoc on the 2.5L and need to be working 100%. You cant eliminate the EGR valve until a correct BRAND NEW AC Delco/Delphi valve (auto or manual) is installed. Even an old cleaned valve may or may NOT work. Please post back if you have a new valve to try out.
	[Reply w/Quote]

10-28-2009, 04:16 PM	#30
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle No did not install a new egr. How do you suspect that it's causing it to be a balles wonder after more than 1/4 throttle? I'll do the compression test again and see if that turns up any new evidence.
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10-28-2009, 08:53 PM	#31
Shaddix Registered User Join Date: Apr 2003 Posts: 144 Location: Astoria, Oregon User is: OffLine	Re: 89 2.5L Surge at a steady Idle Quote: Originally Posted by popo09 No did not install a new egr. How do you suspect that it's causing it to be a balles wonder after more than 1/4 throttle? I'll do the compression test again and see if that turns up any new evidence. Well, these EGR's are a nightmare. Some work, most dont. I am assuming that you have already checked your TPS sensor first and got a smooth sweep of voltage, and also am assuming that you CTS sensor has been spec'ed out with an ohm meter at different temps to make sure its OK. I dont know how to check the MAP, but if its not those, then I would go EGR next.
	[Reply w/Quote]

10-29-2009, 08:38 PM	#32
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle Just checked the compression again with all the plugs out like your supposed to do and it checks out. 135 125 125 and 125psi. So no blown head gasket here. Going to pop the valve cover and check the cam timing by checking the lifters on the compression stroke of each cylinder.
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11-01-2009, 07:49 PM	#33
popo09 Registered User Age: 26 Join Date: Oct 2009 Posts: 17 Location: User is: OffLine	Re: 89 2.5L Surge at a steady Idle i meant check the cam lift.. seeing if it had a swiped cam lobe and no it doesnt! put the valve cover back on and come to find out it was out of time! So put it in time and it barks second gear now lol.., but it still has the surge that it had when this all started! u can actually look at the injector firing in the tb and see it pulse! so does that point to the computer? anyone have any suggestions?
	[Reply w/Quote]

11-02-2009, 12:04 PM	#34
Shaddix Registered User Join Date: Apr 2003 Posts: 144 Location: Astoria, Oregon User is: OffLine	Re: 89 2.5L Surge at a steady Idle Quote: Originally Posted by popo09 i meant check the cam lift.. seeing if it had a swiped cam lobe and no it doesnt! put the valve cover back on and come to find out it was out of time! So put it in time and it barks second gear now lol.., but it still has the surge that it had when this all started! u can actually look at the injector firing in the tb and see it pulse! so does that point to the computer? anyone have any suggestions? The surge you are feeling, most likley, is the computer looking for the EGR system. You have deleted it on your ride, and the computer is severely leaning out the fuel mixture. The only way to fix it because of your blockoff plate, is to call Sinister Performance and get a custom chip for $55. They remove the EGR function alltogether, and it seems like its the only way to go. I did read that you tried installing an old valve, but I did the same and mine isnt working either. Did you put the solenoid back on and both vacuum lines? Last edited by Shaddix : 11-02-2009 at 12:09 PM.
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