1988 GMC S-15 2.5 won't start..

8ty8 LS1 · 11-14-2008, 01:46 PM

just got back from a trip to the mall, parked the truck outside for a few hours...go to leave again, and it will turn over, but no fire. check for spark and fuel, as far as i can see i have neither. can this be a pick up coil problem? i'm just kind of lost here...

tashirosgt · 11-14-2008, 09:03 PM

Check that your camshaft is turning. Take the cap off the distributor and see that the rotor turns while someone cranks the engine. A stripped timing gear would explain lack of both spark and fuel. The rotor wouldn't turn. I don't know how the computer knows not to supply fuel when the camshaft isn't turning, but on the S-10 1987 Sonoma that I've dealt with, it is that smart.

blackspawn67 · 11-15-2008, 10:56 PM

Fuel relay, fuel pump

lesterl · 11-16-2008, 10:57 AM

Relay would only cause delayed starts untill the Oil Pressure came above 4 psi, then the oil pressure sender would engage pump.

Does the pump make a priming squeel from the area of the gas cap (take gas cap off)?

If it is not sparking and rotor is turning, could be pick up coil or ignition module or ECM as all could have something to do with fuel delivery as well (injector firing).

Have you checked your fuses?

Freek · 11-18-2008, 11:59 PM

I doubt it's coil. A lot of people are having these problems.

We had the exact same problem, ignition control module and fuel pump fixed it. Spent about $100 and did the work ourselves, easy fix.

lesterl · 11-19-2008, 12:17 AM

If rotor in dizzy isnt turning you may have lost the timing gears, common issue with the fiber gearset in the engines.

bobadkins · 11-25-2008, 03:26 AM

It was the fuel pump when my s10 acted this way, but, I have heard of the fiber cam gear loosing teeth and you won't start until you replace the gear.

I pulled the bed and replaced the pump with some OEM pump from Advance Auto. It lasted 100 miles and failed. The intake hole in the pump was MUCH smaller than than the original. So, I got a new Delphi pump from another store (one dollar CHEAPER) and have never had another problem. Stick with Delco and Delphi unless you are looking for performance parts. The Chinese parts just do not work as well.

chevybaby863 · 01-03-2009, 04:49 PM

i have an 86' s10 5spd manual 4x4 i seem to be having a similar problem with the noe fuel delivery. as for the other par to of the problem i do have fire, but no fuel. i have yet to test the fuel pump and i believe the ignition control module is new, and still no fire. any suggestions?

lesterl · 01-04-2009, 01:02 AM

Check the coil, check for 12v on coil. Have ICM pulled and tested at a parts store. Next time, start a new thread, keeps the old ones cleaner. :-)

dimerunner88 · 01-04-2009, 04:36 PM

chevybaby, so you have fuel or not? your post was kind of confusing

11-14-2008, 01:46 PM	#1
8ty8 LS1 Registered User Age: 24 Join Date: Nov 2008 Posts: 1 Location: User is: OffLine	1988 GMC S-15 2.5 won't start.. just got back from a trip to the mall, parked the truck outside for a few hours...go to leave again, and it will turn over, but no fire. check for spark and fuel, as far as i can see i have neither. can this be a pick up coil problem? i'm just kind of lost here...
	[Reply w/Quote]

11-14-2008, 09:03 PM	#2
tashirosgt Registered User Join Date: Oct 2005 Posts: 69 Location: User is: OffLine	Re: 1988 GMC S-15 2.5 won't start.. Check that your camshaft is turning. Take the cap off the distributor and see that the rotor turns while someone cranks the engine. A stripped timing gear would explain lack of both spark and fuel. The rotor wouldn't turn. I don't know how the computer knows not to supply fuel when the camshaft isn't turning, but on the S-10 1987 Sonoma that I've dealt with, it is that smart.
	[Reply w/Quote]

11-15-2008, 10:56 PM	#3
blackspawn67 Registered User Age: 41 Join Date: Mar 2008 Posts: 53 Location: New Bern,NC User is: OffLine	Re: 1988 GMC S-15 2.5 won't start.. Fuel relay, fuel pump
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11-16-2008, 10:57 AM	#4
lesterl Wire Splicin Fool :-) Age: 29 Join Date: May 2008 Posts: 2,145 Location: Kansas City Area User is: OffLine	Re: 1988 GMC S-15 2.5 won't start.. Relay would only cause delayed starts untill the Oil Pressure came above 4 psi, then the oil pressure sender would engage pump. Does the pump make a priming squeel from the area of the gas cap (take gas cap off)? If it is not sparking and rotor is turning, could be pick up coil or ignition module or ECM as all could have something to do with fuel delivery as well (injector firing). Have you checked your fuses?
	[Reply w/Quote]

11-18-2008, 11:59 PM	#5
Freek Shred The Shit Age: 16 Join Date: Feb 2008 Posts: 325 Location: Indianapolis, IN User is: OffLine	Re: 1988 GMC S-15 2.5 won't start.. I doubt it's coil. A lot of people are having these problems. We had the exact same problem, ignition control module and fuel pump fixed it. Spent about $100 and did the work ourselves, easy fix.
	[Reply w/Quote]


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11-19-2008, 12:17 AM	#6
lesterl Wire Splicin Fool :-) Age: 29 Join Date: May 2008 Posts: 2,145 Location: Kansas City Area User is: OffLine	Re: 1988 GMC S-15 2.5 won't start.. If rotor in dizzy isnt turning you may have lost the timing gears, common issue with the fiber gearset in the engines.
	[Reply w/Quote]

11-25-2008, 03:26 AM	#7
bobadkins Registered User Age: 53 Join Date: May 2008 Posts: 18 Location: User is: OffLine	Re: 1988 GMC S-15 2.5 won't start.. It was the fuel pump when my s10 acted this way, but, I have heard of the fiber cam gear loosing teeth and you won't start until you replace the gear. I pulled the bed and replaced the pump with some OEM pump from Advance Auto. It lasted 100 miles and failed. The intake hole in the pump was MUCH smaller than than the original. So, I got a new Delphi pump from another store (one dollar CHEAPER) and have never had another problem. Stick with Delco and Delphi unless you are looking for performance parts. The Chinese parts just do not work as well.
	[Reply w/Quote]

01-03-2009, 04:49 PM	#8
chevybaby863 Registered User Age: 22 Join Date: Jan 2009 Posts: 1 Location: User is: OffLine	Re: 1988 GMC S-15 2.5 won't start.. i have an 86' s10 5spd manual 4x4 i seem to be having a similar problem with the noe fuel delivery. as for the other par to of the problem i do have fire, but no fuel. i have yet to test the fuel pump and i believe the ignition control module is new, and still no fire. any suggestions?
	[Reply w/Quote]

01-04-2009, 01:02 AM	#9
lesterl Wire Splicin Fool :-) Age: 29 Join Date: May 2008 Posts: 2,145 Location: Kansas City Area User is: OffLine	Re: 1988 GMC S-15 2.5 won't start.. Check the coil, check for 12v on coil. Have ICM pulled and tested at a parts store. Next time, start a new thread, keeps the old ones cleaner. :-)
	[Reply w/Quote]

01-04-2009, 04:36 PM	#10
dimerunner88 is that fender straight?? Age: 22 Join Date: Jan 2007 Posts: 18,065 Location: Clay City,IN/Martinsville,IL User is: OffLine	Re: 1988 GMC S-15 2.5 won't start.. chevybaby, so you have fuel or not? your post was kind of confusing
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