Help please? New motor 4.3 Cranks but no start/spark?? - S-10 Forum
S-10 Forum is the resource on GM S-series trucks, Suspension, engine information, Body Modifications, painting tutorials.  Modifications to suit every need, budget and whim

Help please? New motor 4.3 Cranks but no start/spark??

Go Back   S-10 Forum > Engine and Drivetrain Tech > 262ci Forum (4.3)
New User? Register Forgot Password


 
LinkBack Thread Tools
Old 08-21-2009, 10:05 PM   #1
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Help please? New motor 4.3 Cranks but no start/spark??

Just put a new motor in the truck got everything hooked up the way it's supposed to be. Motor ran before with no problems. Seems as though there is an electrical problem or something wrong with the distributor.. It's in a 98 s10 v6 4.3 liter and If anyone has any answers please let me know.. The motor Cranks but when I checked the coil plug for spark it only sparks one time. Is this due to a sensor? my timing? wtf? please help. been working on it forever. Tried replacing coil.. didn't work. Any other suggestions PLEASE PLEASE help me out. so frustrated and tired.
Old 08-22-2009, 02:04 AM   #2
Registered User
 
White96ZQ8's Avatar
 
Age: 24
Join Date: Jan 2007
Posts: 1,601
Location: Moundsville WV, 26041
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Is the truck throwing any codes?
Old 08-22-2009, 03:50 PM   #3
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Should I take it to autozone or something and see if it throws any codes? doesn't the car have to be running for them to test it?
Old 08-22-2009, 06:26 PM   #4
Registered User
 
White96ZQ8's Avatar
 
Age: 24
Join Date: Jan 2007
Posts: 1,601
Location: Moundsville WV, 26041
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

I think autozone has the loan-a-tool deal, you could put some cash down on one and take it home and try it. I think if there are any codes, then all you need to do is have the ignition on, it doesnt have to be running.
Old 08-22-2009, 06:28 PM   #5
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

good idea.. yeah i'm going to give it a shot tomorrow. would be awesome if it told me exactly what was wrong. I just don't understand what's causing it to not spark. if my timing is not right on or what..have first piston at TDC and rotor facing spark plug 1 this is correct? even if this wasn't shouldn't the coil still spark more than the first time? Also. getting plenty of fuel pressure.
Old 08-22-2009, 07:51 PM   #6
Registered User
 
White96ZQ8's Avatar
 
Age: 24
Join Date: Jan 2007
Posts: 1,601
Location: Moundsville WV, 26041
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

If the timing is off you should still be getting spark. It could be the ICM (ignition control module). I think 98s have them?
Old 08-22-2009, 09:08 PM   #7
Wire Splicin Fool :-)
 
lesterl's Avatar
 
Age: 34
Join Date: May 2008
Posts: 8,691
Location: Harrisonville, MO
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Should point at #6 IIRC...... Even then you got to make sure it is on the propper stroke on #1 cyl TDC...
Old 08-22-2009, 09:45 PM   #8
Registered User
 
Ranger72's Avatar
 
Age: 30
Join Date: Sep 2008
Posts: 69
Location:
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Quote: Originally Posted by White96ZQ8
If the timing is off you should still be getting spark. It could be the ICM (ignition control module). I think 98s have them?
Good question, does the 98 still have one? If so, I would start there.

Last edited by Ranger72; 08-22-2009 at 09:48 PM.
Old 08-23-2009, 08:11 PM   #9
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

yeah it has an ignition control module. what get's me is everything was running fine before so why when I hook it back up why would it just take a crap all of a sudden? I'm going to pick up that ICM tomorrow and try it out though. we'll see what happens. I'll let you guys know. Thanks

Last edited by frankie413; 08-23-2009 at 08:14 PM.
Old 08-23-2009, 10:59 PM   #10
Wire Splicin Fool :-)
 
lesterl's Avatar
 
Age: 34
Join Date: May 2008
Posts: 8,691
Location: Harrisonville, MO
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

ICM's arent returnable once you buy one, take yours in and have it tested several X in a row. If it fails, have them check the new one before you take it with you.
Old 08-23-2009, 11:04 PM   #11
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

It's not the ICM. The dude tested it like 6 times. so it got hot.. ICM is good. I'm pissed lol I was hoping that was it. now I have no idea what it is. Should I rent one of the decoders and see if it throws out any codes? What else could it possibly be i don't get it. Coils good, ICM is good. everything's grounded. MAF is hooked up !!! Hoping it's not the distributor. What's that Sensor under the rotor inside the distributor could that be it? The pickup coil? I guess I could try taking that into autzone to have it tested but isn't that just to get the timing right? Should still spark shouldn't it?
Old 08-27-2009, 09:35 PM   #12
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

bump any other ideas?
Old 08-27-2009, 10:14 PM   #13
WICKED 6 RACING
 
disturbing V6's Avatar
 
Age: 30
Join Date: Jul 2009
Posts: 2,071
Location: MD
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

If the pickup is bad the computer won't know when to set off the spark there for no spark. Also if you set it at top dead center the distributor needs to point where ever 1 is on the cap not a cylinder one like on the older motors. The newer 4.3L run the cross spider cap were I believe for some dumb reason they swap cylinder 6 and 1 .
Old 08-29-2009, 06:30 PM   #14
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Well I had my mechanic test the pickup coil and he says it's good. so that factors that out. He thinks I shorted out the PCM somehow
Old 08-29-2009, 08:47 PM   #15
Registered User
 
Age: 24
Join Date: May 2008
Posts: 372
Location: South Jersey
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Have you checked the crank sensor?
Old 08-30-2009, 03:24 PM   #16
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

the crankshaft positioning sensor located on the timing chain coveR? if so yeah. I think that's what might have shorted out the computer possibly. all three wires were exposed and twisted together and there is no specific fuse for that individual sensor.. it now has a new plug and new sensor so I think it may be the PCM
Old 08-31-2009, 01:08 AM   #17
Wire Splicin Fool :-)
 
lesterl's Avatar
 
Age: 34
Join Date: May 2008
Posts: 8,691
Location: Harrisonville, MO
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Maybe the plug was wired wrong...
Old 09-01-2009, 12:12 AM   #18
Registered User
 
Age: 50
Join Date: Aug 2009
Posts: 6
Location:
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

I have been watching this post for a few days because I have been working on a motor with the exact same problem. Here is what I did and what I found.

First, I pulled the crankcase sensor out of the timing chain cover and with the sensor plugged in and the key on, I moved a steel wrench back and forth in front of the sensor, simulating the crank position sprocket.

When I did this, the fuel pump ran, and the coil emitted a series of sparks. This confirmed that the enitre circuit was working.

Next, I installed the sensor again and cranked the engine. No spark. This confirmed that the sensor was not seeing the crank position sprocket.

This made me suspect that the timing chain cover was made wrong, so I measured the distance between the sprocket high point and the outer sensor mounting surface and compared that with a motor at the junk yard. Sure enough, the junk yard motor had about 100 thousandths less distance on that dimension. This would definitely be enough to make the sensor not work.

Next, I went to AutoZone where I had bought the timing chain cover and got another one. I took it to a Chevy garage and compared it to an OEM part. This new AutoZone part measured 64.5 thousandths greater distance from the sensor to the sprocket than the OEM part, also enough to make the sensor not work.

I am convinced without a doubt that the AutoZone timing chain cover made by Pioneer is at fault.

My current plan is to put a rag in the sensor hole and sand the outer mounting surface until the sensor is in range to read the sprocket. I will let you know how it goes.
Old 09-01-2009, 12:12 AM   #19
Registered User
 
Age: 50
Join Date: Aug 2009
Posts: 6
Location:
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

I have been watching this post for a few days because I have been working on a motor with the exact same problem. Here is what I did and what I found.

First, I pulled the crankcase sensor out of the timing chain cover and with the sensor plugged in and the key on, I moved a steel wrench back and forth in front of the sensor, simulating the crank position sprocket.

When I did this, the fuel pump ran, and the coil emitted a series of sparks. This confirmed that the entire circuit was working.

Next, I installed the sensor again and cranked the engine. No spark. This confirmed that the sensor was not seeing the crank position sprocket.

This made me suspect that the timing chain cover was made wrong, so I measured the distance between the sprocket high point and the outer sensor mounting surface and compared that with a motor at the junk yard. Sure enough, the junk yard motor had about 100 thousandths less distance on that dimension. This would definitely be enough to make the sensor not work.

Next, I went to AutoZone where I had bought the timing chain cover and got another one. I took it to a Chevy garage and compared it to an OEM part. This new AutoZone part measured 64.5 thousandths greater distance from the sensor to the sprocket than the OEM part, also enough to make the sensor not work.

I am convinced without a doubt that the AutoZone timing chain cover made by Pioneer is at fault.

My current plan is to put a rag in the sensor hole and sand the outer mounting surface until the sensor is in range to read the sprocket. I will let you know how it goes.
Old 09-02-2009, 02:33 AM   #20
Registered User
 
Age: 50
Join Date: Aug 2009
Posts: 6
Location:
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

The timing chain cover made by Pioneer and sold to me by AutoZone was definitely the reason for my "sparks one time then not again until the key is turned off and back on" problem.

The timing chain cover was made wrong so that it positioned the crankshaft sensor too far back from the timing sprocket for the sensor to work right.

Instead of sanding down the outer surface, I made a tool that fit the hole and cut a 200 thousandths wide groove around the hole, so that the shoulder of the sensor would rest below the original surface and the sensor would be moved closer to the timing sprocket.

First, I cut the groove 50 thousandths deep and mounted the sensor. I had sparks galore when I cranked the engine. So I put everything back together and drove the vehicle. It ran fine for about five minutes, and then started stalling out and throwing DTCs related to the crankshaft sensor. I pulled it back in and took off another 20 thousandths. Now it runs fine. No codes and no missing or rough running.

I have driven it about 40 miles so far tonight with no problems whatever.

That's what happened to me -- for what it is worth.
Old 09-02-2009, 09:28 PM   #21
Wire Splicin Fool :-)
 
lesterl's Avatar
 
Age: 34
Join Date: May 2008
Posts: 8,691
Location: Harrisonville, MO
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Russell, have you had the relearn procedure done also?
Old 09-02-2009, 11:03 PM   #22
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

WOW .. I appreciate this information very much. I also bought the timing chain cover from autozone. I'm not sure on the exact brand I just know it's the one they had with the hole for the sensor! I had a feeling it had something to do with the crankshaft positioning sensor too! I had just ordered the Computer for the truck thinking that was it, maybe i'll hold off on installing it and try this first. I May have to buy the oem part from chevy or something. I was iffy about getting a new one in the firstplace but of course there is no specific gasket for the timing chain cover, you have to buy the whole piece. once again WOW. thank you so much for all of your input and I would be really pissed off if I had put the computer in and it still didn't work.. Whoever makes the timing chain cover needs to correct this problem and I may have to take mine to GM and compare and show Autozone for a refund because that's crap. $70 bucks for a defective part is not cool. Happy I posted here, knew I'd find someone with a similar problem. Thanks a lot. If you have time and can show me exactly how you made the autozone cover work plz let me know!
Old 09-03-2009, 06:43 AM   #23
Registered User
 
Age: 50
Join Date: Aug 2009
Posts: 6
Location:
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Quote: Originally Posted by lesterl
Russell, have you had the relearn procedure done also?
No, and so far it runs great. The relearn procedure is not needed to get the engine running. In fact, the relearn procedure requires the engine to be running, and the coolant temperature to be above 178 degrees before the computer will run the procedure.

If I understand how it works, the computer will eventually relearn the crank angle on its own over time, just like it relearns the fuel mix, altitude, and idle speed. The crank angle relearn procedure just forces it to relearn it all at once.

It is possible I am wrong on this and that I will need to do the relearn procedure. However, I won't know this until I run the engine at high RPMs over an extended period, because that is the only time the crank angle matters. If my power and/or fuel mileage is unacceptable on an extended highway trip, then I will look into it.
Old 09-03-2009, 07:22 AM   #24
Registered User
 
Age: 50
Join Date: Aug 2009
Posts: 6
Location:
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Quote: Originally Posted by frankie413
Thanks a lot. If you have time and can show me exactly how you made the autozone cover work plz let me know!
I found an old 3/8 drive socket that just fit the sensor hole, and using a bandsaw, I cut a slot in two sides of the socket running parallel with the drive axis of the socket. The cut runs half way down the socket starting on the end opposite the 3/8 drive hole.

Next, I took a flat piece of steel that fit in the slot in the socket (the slot is two band saw blade widths in size), and cut it so it would be wider than the socket and about half as high. I cut a channel in the center of the flat piece so that the socket would slide up into the flat piece at the same time that the flat piece was sliding into the slot in the socket. This locked the two pieces together.

Now, I have a cylinder with a "wing" sticking out on two sides. Next I used a file to make a cutting angle on each of the two wings. I cut them in such a way that there is about 3/8 of an inch of the socket in the hole before the cutting edges engage the plastic of the timing chain cover. This engagement in the hole keeps everything aligned.

I put the cutting tool on a ratchet with a short extension, and started turning it in the sensor hole of the timing chain cover, exerting enough axial pressure to make the tool cut the plastic. The chips fall outside the hole, because the socket is plugging the hole.

It was slow work, because I was cautious, and I had to stop from time to time to sharpen the tool. The timing chain cover is made of fiber-filled plastic, and my tool was made of cold-rolled steel. The plastic made short work of the cutting edge. In about two turns, the cutter was dull. I didn't have time to harden it, and I didn't have a conveniently shaped piece of tool steel. None the less, it worked.

Another way this could be done would be to cut down a large (1.5 inch) drill bit to do the job. That way you would be working with tool steel from the beginning. I thought about doing it this way, but decided to use the socket instead because it was faster. The whole thing took less than 20 minutes to make.

I hope this helps.
Old 09-03-2009, 07:42 PM   #25
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

thanks for that. If you could take a picture that would be awesome. I can kind of picture what you're saying but if you have a picture of your special tool that would probably help out a lot. I'm kind of iffy about doing it because it's only about a $40 difference between the autozone part and dealer part and I may still be able to take this one back to autozone if I don't mess it up lol.. If it's really that easy i'd like to try it. basically what you're doing is making the hole slightly bigger so that the sensor slides in closer to the chain correct?
Old 09-03-2009, 07:42 PM   #26
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

once again. I greatly appreciate your input. You are my hero
Old 09-05-2009, 10:41 PM   #27
Registered User
 
Age: 50
Join Date: Aug 2009
Posts: 6
Location:
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Quote: Originally Posted by frankie413
thanks for that. If you could take a picture that would be awesome. I can kind of picture what you're saying but if you have a picture of your special tool that would probably help out a lot.
Here they are in two pieces:


And here they are put together:


Very crude, but effective.

It does not make the hole bigger. The cylinder made from a socket is the same size as the hole. The two "wings" cut a step ledge around the hole so the sensor can go deeper into the hole and closer to the timing sprocket on the crankshaft.

Sorry I cannot give you a picture of the timing chain cover, because my son drove the vehicle to a concert.

My only reason for doing it his way was to save the time and effort of changing the timing chain cover. The Bravada has SmartTrack, so there is a driveshaft within 3/4 inch of the pan. As you know, the pan has to come off to change the timing chain cover, because the cover and the pan mate in such a way the the cover has to go on first and then the pan. Otherwise, you have no hope of making a good seal at the pan/cover interface, and it will leak oil forever. Besides, the chances of getting the timing chain cover twisted around so that it goes into the slot in the pan without cutting the crankshaft seal is near zero. Since I have SmartTrack, I would have to remove the motor mounts, lift the engine, and hope I had enough room to pull the pan. All that after I take out the radiator, remove the fan, alternator, Power steering pump, and air conditioning pump, and pull the harmonic balancer so I can get to the timing chain cover. On a regular engine, the standard time for this operation is 10 hours. On a SmartTrack, double or triple that.

The idea of doing all that gave me the hives - hence the tool.
Old 09-09-2009, 12:10 AM   #28
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

nice! sweet that makes it way better. I'm definitely going to give it a try b4 i buy another from chevy because I can't find my reciept from autozone so they're not going to take it back considering it's been installed already lol. I can't thank you enough bro. Been a huge help. I'll be trying this out hopefully tomorrow and i'll definitely let you know if it solves the problem. wish me luck!
Old 09-13-2009, 04:43 PM   #29
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Alright! so I ground down the sensor hole, got the sensor closer, Sparks galore! NICE. problem solved. Got timing all lined up, Truck started! yeahh!! Now. Truck sounds like crap, cylinder 5 misfire is the code i'm getting.? any ideas? I tried switching spark plug WIRE 3 and 5 and the noise was TOTALLY different, and I couldn't get a code reading after that. I decided it must have something to do with the spark plug wires then? because all i changed was the wires and the sound was very different. I bought all new wires and tried it out and still having same problem. No codes being thrown now though. any ideas?
Old 09-14-2009, 10:50 PM   #30
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

!bump! any ideas want cylinder 5 misfire.. what's everyone's first take? didn't misfire b4 new engine. finally got spark and timing is all lined up. plugs brand new, tried new wires. what is the main cause?
Old 09-15-2009, 12:13 AM   #31
Wire Splicin Fool :-)
 
lesterl's Avatar
 
Age: 34
Join Date: May 2008
Posts: 8,691
Location: Harrisonville, MO
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Bad plug wire, bad cap, bad plug, bad FI, bad compression, etc.
Old 09-27-2009, 02:57 AM   #32
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

So, Thanks too all your help, especially russelk, and my mechanic, My truck is back up and running, running great. So no spark was because of the stupid part by pioneer sold at autozone so beware! Timing chain cover is no good. Causes crankshaft sensor to sit too far back from timing chain without getting a reading to give the coil a spark. Anyways I ground that down like russelk explained and got spark, Then I was getting misfires like crazy and did a little research around the forum, found out it's common with our crappy scpi or whatever fuel injectors. Turns out 4 of my injectors weren't shooting out any fuel so I move the ball at the end of the injectors around until they shot out and everything is great now! That'll be my next update when I have some money is to get the new MFI injectors. Too bad I don't live in California where I could get them for free
Old 09-27-2009, 02:57 AM   #33
Work in Progress
 
Age: 24
Join Date: Aug 2007
Posts: 405
Location: Las Vegas, NV
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Once again. Thanks a lot russelk, Would have NEVER figured it out without you. Love this forum.
Old 10-20-2009, 12:47 PM   #34
Registered User
 
Join Date: Oct 2009
Posts: 17
Location:
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

Hey guys.

Im too is having this issue, but I am not getting any spark at all at the coil. NOT even ONE! I have replaced the IGN module, the COIL, and the CRK sensor. I also had to replaced the harness clip to the IGN module because the power, pink, wire was alittle torn and was exposing the actual copper wire.

I will test the CRK sensor by simulating Russel's procedure of checking if the sensor and the crank pick up wheel is within its specified gap. Otherwise, would you guys have anyother ideas on what it maybe for me to not get any spark at all.

Last edited by sao1; 10-20-2009 at 12:50 PM.
Old 10-20-2009, 07:48 PM   #35
Wire Splicin Fool :-)
 
lesterl's Avatar
 
Age: 34
Join Date: May 2008
Posts: 8,691
Location: Harrisonville, MO
User is: OffLine
Re: Help please? New motor 4.3 Cranks but no start/spark??

SAO1 Check the fuse feeding wire to the pink wire for the coil. Start your own thread.....
Sponsored Links
Advertisement
 

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the S-10 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 09:08 AM.

Powered by vBulletin® Copyright ©2000 - 2011, Jelsoft Enterprises Ltd. SEO by vBSEO 3.2.0
SEO by vBSEO
vBulletin Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.