1993 S-15 Jimmy: Cranks but won't start

[JDMack]

I have a 1993 GMC S-15 Jimmy, 4.3 Vortec V6 4x4. It has been a great truck so far and I've never had major prolems. I have given it a tune-up (plugs/wires, air filter, fuel filter, pcv valve) in the last year and it has also recently got a new fuel pump.

Yesterday I got in it and started it up, drove to the end of the street and as I came to the stop sign, it stalled. It cranks over great but won't restart. I let it sit over night (after me and a friend towed it home) and today I tried starting it and it fired once then died, but continues to crank over good.

I can hear the fuel pump kicking on when I turn the key on (and it has over a 1/2 tank of gas). I have checked the fuse for the EBM and it is good. I checked the spark and it has good spark. My next guess is maybe the fuel pressure regulator might be bad? I do not know where that is located on the truck.

Any help, suggestions and ideas would be really appreciated!

Thank you, J. Mack

[troubles789]

Under the vortec top of the engine, you have to split the intake, takes less then a hour to replace. Cpi is known for going out on the W motors. Just do a cpi search. Loads of info.

[jsgold]

Be SURE you are getting good spark too. I had the ignition module replaced months ago due to random starting and stalling. Thought it was firing but it was weak and random. It sits inside your distributor. Get fuel pressure tested and check the plenum per previous post. You can check for "washing" areas inside plenum by removing the top cap on plenum. Check your oil for gas smell. Again there is plenty on this listed on this forum and Blazer forum. Strongly suggest checking pressure FIRST. These engines require high pressure. Takes 55-60 lbs to start. Too low and stalls. Check for good pressure and check for bleed off. If you wind up replacing the regulator, replace the entire spider assy and nut kit (hose assy).

[tinlizzytwo]

Originally Posted by jsgold

Be SURE you are getting good spark too. I had the ignition module replaced months ago due to random starting and stalling. Thought it was firing but it was weak and random. It sits inside your distributor. Get fuel pressure tested and check the plenum per previous post. You can check for "washing" areas inside plenum by removing the top cap on plenum. Check your oil for gas smell. Again there is plenty on this listed on this forum and Blazer forum. Strongly suggest checking pressure FIRST. These engines require high pressure. Takes 55-60 lbs to start. Too low and stalls. Check for good pressure and check for bleed off. If you wind up replacing the regulator, replace the entire spider assy and nut kit (hose assy).

So was the problem the ignition module? Someone else had told me this might be the case with mine? I went to Auto Zone and he sold me a MAP sensor even though I told him I wanted the ECM. I know that when the ECM goes out it will cause it to not start. Will it also cause intermittant stalling and random starting? Thanks

[jsgold]

Replaced igntion module. Solved all problems.

[tinlizzytwo]

Originally Posted by jsgold

Be SURE you are getting good spark too. I had the ignition module replaced months ago due to random starting and stalling. Thought it was firing but it was weak and random. It sits inside your distributor. Get fuel pressure tested and check the plenum per previous post. You can check for "washing" areas inside plenum by removing the top cap on plenum. Check your oil for gas smell. Again there is plenty on this listed on this forum and Blazer forum. Strongly suggest checking pressure FIRST. These engines require high pressure. Takes 55-60 lbs to start. Too low and stalls. Check for good pressure and check for bleed off. If you wind up replacing the regulator, replace the entire spider assy and nut kit (hose assy).

Okay, well that solved my problem (at that time) but now it won't start again. I was having trouble with the Left bank plug and wire it appeared to be arcing. Drove it for a week and got into it this afternoon and it cranks but won't start. Replaced the plug wire last week along the the distributor coil wire today. Rechecked all my wires again and the thing still isn't starting. Last month finished with a complete fuel system job, including pump, spyder injectors and nut kit, filter, sending unit, pump etc. Checked all my vacumm lines. Anybody got any ideas? Just got it back from having front brakes put on and this is costing me more than a college education for my kid. Thanks!!