88 2.5 problems

88s10owner · 08-16-2009, 11:47 AM

I have an 88 S10 with the 2.5 motor. Has always been hard to start (Takes a lot of cranking to get it to fire up), but a few weeks ago it got to where it is darn near impossible to keep idling. Checked EGR and PCV, both good. When you can get it driving, the engine surges at times. Hooked up a vacuum gauge, and it shows a stead needle. Will be checking codes this morning to see if anything is stored. Am thinking maybe fuel pump???

Any and all suggestions are greatly appreciated.

lesterl · 08-16-2009, 09:19 PM

EGR valve on these are NOTORIOUS. Hard starting could be a bad fuel pump relay, or like you thought a pump. Would check the fuel spray myself.

jdbjicase · 09-03-2009, 12:35 AM

Quote: Originally Posted by lesterl

Would check the fuel spray myself.

So if you spray yourself with fuel the truck will run?

lesterl · 09-03-2009, 09:37 PM

Quote: Originally Posted by jdbjicase

So if you spray yourself with fuel the truck will run?

TOO FUNNY DUDE!!!! I didnt even see that when I wrote it!!!!

jdbjicase · 09-04-2009, 12:32 AM

Everybody has those moments. I'm just one of those people who points them out and humiliates the one who said it to the point of contemplating suicide. lol

lesterl · 09-04-2009, 01:19 AM

I CAN NOT SELF TERMINATE..... ha

Shaddix · 09-04-2009, 04:06 AM

How did you check the EGR valve??? Are you SURE you can eliminate it already??? Ive read a few posts and this sucker is a ROYAL P-O-S!

It really messes with a lot of 2.5's... ones that run GREAT when you take the EGR solenoid plug off and run it like that aside from the ping... Like Mine!

lesterl · 09-05-2009, 12:05 PM

You could also burn a hole in a piston if you arent careful (getting a new PROM, or running it a little rich), my 89 had that happen the port on the EGR was plugged up.....

Shaddix · 09-06-2009, 12:20 AM

Quote: Originally Posted by lesterl

You could also burn a hole in a piston if you arent careful (getting a new PROM, or running it a little rich), my 89 had that happen the port on the EGR was plugged up.....

Shit. I need to really look into this mess then. When I hear my engine doing some heavy pinging while pulling a long 55MPH hill in 5th gear, I usually just lay into the gas a bit more and the ping goes away. I religiously use premium fuel to help compensate for the EGR being gone, but it still does ping sometimes. Maybe that pinging is the valve burning off! I need to look into the Sinister PROM chip.....

lesterl · 09-06-2009, 07:36 PM

Pinging is early detonation and not good, might try to seafoam the intake you may have some carbon that is causing some of the pinging....

Shaddix · 09-07-2009, 02:16 AM

Quote: Originally Posted by lesterl

Pinging is early detonation and not good, might try to seafoam the intake you may have some carbon that is causing some of the pinging....

I am a Seafoam nut, and I also use a lot of AMSOIL Power Foam. I usually use seafoam thru the vacuum port and dump it down the TBI throat. The Power Foam works KILLER on the IAC valve and places where a foam can stick to something in a tough spot. I cannot locate an ACDelco EGR valve anywhere; Should I try my luck and get a NAPA Auto Parts replacement? They look at me as if I am retarded when I try to tell them about the spring pressures being different and such! I just dunno what to do?!

lesterl · 09-07-2009, 01:34 PM

There is also a different part # for a Manual Transmission and Automatic Valve, I would suspect they are different also (may be the difference in spring tension people worry about too!)

88s10owner · 09-18-2009, 05:22 PM

Hooked up a fuel pressure tester last night, and was barely able to get 2 psi. Trying a new filter tonight, if that doesn't improve things I am going to remove the pump and check the screen in the tank to see if it is plugged.

lesterl · 09-18-2009, 07:41 PM

Also check the rubber hose connecting the pump to the steel line as it gets soft and can crack, also could just be a bad pump. Check for 12v at pump, check the grounds on the frame.

88s10owner · 09-29-2009, 01:11 PM

It was the fuel pump. Put in a new pump and it is running great now. Ironically enough, a few days later was driving my 88 K1500, and it died and left me stranded. Turned out to be the fuel pump as well. I am getting pretty good at replacing fuel pumps...

lesterl · 09-29-2009, 08:25 PM

Yeah, you learn real fast on those things!!!! :-)

ratdude · 09-29-2009, 08:54 PM

88s10owner ,
I once killed 3 pumps in a month
93 pontiac Bonneville ate the sending unit ( might as well do the pump too )
2 weeks later wifes Grand Marquis didn't start ( yup another one )

week after that my 87 S-10 croaked ( yup pump , but it had 200k 0n it )

I really question the quality of the gas we bought that month

The real beef was i drove a semi OTR and didn't have time to do the work myself , shop charged me bout 1200 bucks that month

certainly pays to do it yourself

drag87 · 10-26-2009, 02:29 PM

`what would cuase my 2.5 to run at a really high idle till i go down the road and it goed to normal, but if i shut it off and restart it doed the same thing also the first start of the day it takes forever to start

tyson_cbr · 10-26-2009, 03:26 PM

Quote: Originally Posted by drag87

`what would cause my 2.5 to run at a really high idle till i go down the road and then it idles normally, but if i shut it off and restart it does the same thing also the first start of the day it takes forever to start

Fixed.

you gotta learn how to spell bro or people are gonna give you a lotta shit on here. . .Oh and another piece of advice mods get mad when you make a thread about something then go into other threads asking the same question. . Its called 'whoring' people get bitchy about these things. but glad to see you actually using this site its great for s-series owners!!

God plastic and adhesives class is boring.

lesterl · 10-26-2009, 10:06 PM

BuckyBoy02 · 10-31-2009, 01:32 AM

lester1: you mentioned in your post on 8-16-09 about checking your spray pattern. How do you do that? My 88 S-10 has the exact same problem as 88s10owner's post#1. When my engine was running, (currently won't start), looking into the TBI I only saw gas swirling on the inside walls of the TBI, and drops of gas. Should you be able to see an actual spray pattern? Injector possibly partially plugged? Any help?

dimerunner88 · 10-31-2009, 01:38 AM

it should spray out a fan like mist of fuel onto the throttle blade

BuckyBoy02 · 10-31-2009, 02:27 AM

It looks like it's just dumping in from the injector. Could this explain the hard starting? Like it's flooding out?

lesterl · 11-09-2009, 11:59 PM

Yes, use a timing light aimed at the spray pattern should be conical in shape and fine mist, no drops should be detected, check the rubber gaskets on the injector as they can rot and cause drippage, also check fuel pressure.

08-16-2009, 11:47 AM	#1
88s10owner Registered User Join Date: Aug 2009 Posts: 3 Location: User is: OffLine	88 2.5 problems I have an 88 S10 with the 2.5 motor. Has always been hard to start (Takes a lot of cranking to get it to fire up), but a few weeks ago it got to where it is darn near impossible to keep idling. Checked EGR and PCV, both good. When you can get it driving, the engine surges at times. Hooked up a vacuum gauge, and it shows a stead needle. Will be checking codes this morning to see if anything is stored. Am thinking maybe fuel pump??? Any and all suggestions are greatly appreciated.
	[Reply w/Quote]

08-16-2009, 09:19 PM	#2
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems EGR valve on these are NOTORIOUS. Hard starting could be a bad fuel pump relay, or like you thought a pump. Would check the fuel spray myself.
	[Reply w/Quote]

09-03-2009, 12:35 AM	#3
jdbjicase Registered User Age: 22 Join Date: May 2007 Posts: 78 Location: Currently Camp Lejeune, but I am originally from Illinois User is: OffLine	Re: 88 2.5 problems Quote: Originally Posted by lesterl Would check the fuel spray myself. So if you spray yourself with fuel the truck will run?
	[Reply w/Quote]

09-03-2009, 09:37 PM	#4
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems Quote: Originally Posted by jdbjicase So if you spray yourself with fuel the truck will run? TOO FUNNY DUDE!!!! I didnt even see that when I wrote it!!!!
	[Reply w/Quote]

09-04-2009, 12:32 AM	#5
jdbjicase Registered User Age: 22 Join Date: May 2007 Posts: 78 Location: Currently Camp Lejeune, but I am originally from Illinois User is: OffLine	Re: 88 2.5 problems Everybody has those moments. I'm just one of those people who points them out and humiliates the one who said it to the point of contemplating suicide. lol
	[Reply w/Quote]

09-04-2009, 01:19 AM	#6
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems I CAN NOT SELF TERMINATE..... ha
	[Reply w/Quote]

09-04-2009, 04:06 AM	#7
Shaddix Registered User Join Date: Apr 2003 Posts: 148 Location: Astoria, Oregon User is: OffLine	Re: 88 2.5 problems How did you check the EGR valve??? Are you SURE you can eliminate it already??? Ive read a few posts and this sucker is a ROYAL P-O-S! It really messes with a lot of 2.5's... ones that run GREAT when you take the EGR solenoid plug off and run it like that aside from the ping... Like Mine!
	[Reply w/Quote]

09-05-2009, 12:05 PM	#8
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems You could also burn a hole in a piston if you arent careful (getting a new PROM, or running it a little rich), my 89 had that happen the port on the EGR was plugged up.....
	[Reply w/Quote]

09-06-2009, 12:20 AM	#9
Shaddix Registered User Join Date: Apr 2003 Posts: 148 Location: Astoria, Oregon User is: OffLine	Re: 88 2.5 problems Quote: Originally Posted by lesterl You could also burn a hole in a piston if you arent careful (getting a new PROM, or running it a little rich), my 89 had that happen the port on the EGR was plugged up..... Shit. I need to really look into this mess then. When I hear my engine doing some heavy pinging while pulling a long 55MPH hill in 5th gear, I usually just lay into the gas a bit more and the ping goes away. I religiously use premium fuel to help compensate for the EGR being gone, but it still does ping sometimes. Maybe that pinging is the valve burning off! I need to look into the Sinister PROM chip.....
	[Reply w/Quote]

09-06-2009, 07:36 PM	#10
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems Pinging is early detonation and not good, might try to seafoam the intake you may have some carbon that is causing some of the pinging....
	[Reply w/Quote]

09-07-2009, 02:16 AM	#11
Shaddix Registered User Join Date: Apr 2003 Posts: 148 Location: Astoria, Oregon User is: OffLine	Re: 88 2.5 problems Quote: Originally Posted by lesterl Pinging is early detonation and not good, might try to seafoam the intake you may have some carbon that is causing some of the pinging.... I am a Seafoam nut, and I also use a lot of AMSOIL Power Foam. I usually use seafoam thru the vacuum port and dump it down the TBI throat. The Power Foam works KILLER on the IAC valve and places where a foam can stick to something in a tough spot. I cannot locate an ACDelco EGR valve anywhere; Should I try my luck and get a NAPA Auto Parts replacement? They look at me as if I am retarded when I try to tell them about the spring pressures being different and such! I just dunno what to do?!
	[Reply w/Quote]

09-07-2009, 01:34 PM	#12
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems There is also a different part # for a Manual Transmission and Automatic Valve, I would suspect they are different also (may be the difference in spring tension people worry about too!)
	[Reply w/Quote]

09-18-2009, 05:22 PM	#13
88s10owner Registered User Join Date: Aug 2009 Posts: 3 Location: User is: OffLine	Re: 88 2.5 problems Hooked up a fuel pressure tester last night, and was barely able to get 2 psi. Trying a new filter tonight, if that doesn't improve things I am going to remove the pump and check the screen in the tank to see if it is plugged.
	[Reply w/Quote]

09-18-2009, 07:41 PM	#14
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems Also check the rubber hose connecting the pump to the steel line as it gets soft and can crack, also could just be a bad pump. Check for 12v at pump, check the grounds on the frame.
	[Reply w/Quote]

09-29-2009, 01:11 PM	#15
88s10owner Registered User Join Date: Aug 2009 Posts: 3 Location: User is: OffLine	Re: 88 2.5 problems It was the fuel pump. Put in a new pump and it is running great now. Ironically enough, a few days later was driving my 88 K1500, and it died and left me stranded. Turned out to be the fuel pump as well. I am getting pretty good at replacing fuel pumps...
	[Reply w/Quote]

09-29-2009, 08:25 PM	#16
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems Yeah, you learn real fast on those things!!!! :-)
	[Reply w/Quote]

09-29-2009, 08:54 PM	#17
ratdude Registered User Join Date: Apr 2009 Posts: 47 Location: User is: OffLine	Re: 88 2.5 problems 88s10owner , I once killed 3 pumps in a month 93 pontiac Bonneville ate the sending unit ( might as well do the pump too ) 2 weeks later wifes Grand Marquis didn't start ( yup another one ) week after that my 87 S-10 croaked ( yup pump , but it had 200k 0n it ) I really question the quality of the gas we bought that month The real beef was i drove a semi OTR and didn't have time to do the work myself , shop charged me bout 1200 bucks that month certainly pays to do it yourself
	[Reply w/Quote]

10-26-2009, 02:29 PM	#18
drag87 Registered User Age: 22 Join Date: Sep 2009 Posts: 5 Location: User is: OffLine	Re: 88 2.5 problems `what would cuase my 2.5 to run at a really high idle till i go down the road and it goed to normal, but if i shut it off and restart it doed the same thing also the first start of the day it takes forever to start
	[Reply w/Quote]

10-26-2009, 03:26 PM	#19
tyson_cbr hack is wack Age: 21 Join Date: Feb 2007 Posts: 906 Location: so. ill. User is: OffLine	Re: 88 2.5 problems Quote: Originally Posted by drag87 `what would cause my 2.5 to run at a really high idle till i go down the road and then it idles normally, but if i shut it off and restart it does the same thing also the first start of the day it takes forever to start Fixed. you gotta learn how to spell bro or people are gonna give you a lotta shit on here. . .Oh and another piece of advice mods get mad when you make a thread about something then go into other threads asking the same question. . Its called 'whoring' people get bitchy about these things. but glad to see you actually using this site its great for s-series owners!! God plastic and adhesives class is boring.
	[Reply w/Quote]

10-26-2009, 10:06 PM	#20
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems
	[Reply w/Quote]

10-31-2009, 01:32 AM	#21
BuckyBoy02 Registered User Join Date: Sep 2009 Posts: 24 Location: Plain City, Ohio User is: OffLine	Re: 88 2.5 problems lester1: you mentioned in your post on 8-16-09 about checking your spray pattern. How do you do that? My 88 S-10 has the exact same problem as 88s10owner's post#1. When my engine was running, (currently won't start), looking into the TBI I only saw gas swirling on the inside walls of the TBI, and drops of gas. Should you be able to see an actual spray pattern? Injector possibly partially plugged? Any help?
	[Reply w/Quote]

10-31-2009, 01:38 AM	#22
dimerunner88 whore turned lurker Age: 23 Join Date: Jan 2007 Posts: 19,767 Location: Clay City,IN User is: OffLine	Re: 88 2.5 problems it should spray out a fan like mist of fuel onto the throttle blade
	[Reply w/Quote]

10-31-2009, 02:27 AM	#23
BuckyBoy02 Registered User Join Date: Sep 2009 Posts: 24 Location: Plain City, Ohio User is: OffLine	Re: 88 2.5 problems It looks like it's just dumping in from the injector. Could this explain the hard starting? Like it's flooding out?
	[Reply w/Quote]

11-09-2009, 11:59 PM	#24
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 4,408 Location: Harrisonville, MO User is: OffLine	Re: 88 2.5 problems Yes, use a timing light aimed at the spray pattern should be conical in shape and fine mist, no drops should be detected, check the rubber gaskets on the injector as they can rot and cause drippage, also check fuel pressure.
	[Reply w/Quote]