2000 4.3 Gm V6 Starts Then Immediately Dies

Guys,
My jeep died driving the other week. Going along, everything is fine, then dies. Pull over, crank, no start. I towed it home. Thought it was fuel pump, replaced it. Not the problem.

I have a Howell harness and a Howell flashed ECU. Supposed to disable VATS (security system) and disable the auto transmission.

I looked at the fuse block and a 15 amp fuse from Howell was blown. Changed this fuse and now it starts but immediately dies, every time. Runs for about 2 seconds and thats it.

Who has info on this particular engine? Astro, safari etc..

 

Does the fuel pump prime and run, or just prime?

 

It primes. No idea if it runs because it dies after a second. This jeep ran fine until it didn't and would not start at all when it died on the road. The fuel pump is new.

 

If it has a return line you can jumper the pump relay and check pressure.

I'm thinking it is a fuel issue because it is a sudden stall with restart. I'm guessing the 15a fuse includes the pump like AFI.

 

Pressure should be fine. If it has less than 58 lbs it wont even start.

This engine is 96-02

This outlines the symptoms
https://www.locksmithledger.com/key...eneral-motors-vehicles-equipped-with-passlock

 

Code is P1361. Says low voltage ignition coil module. Replaced it and the crank sensor. The symptoms are still the same. Cranks, starts immediately dies. No other codes, all wires are good Cap and rotor are fine, etc.

All thats left is ECU I guess? I dunno. Throwing parts at it .

Need to check ignition with to make sure it hasn't failed....

 

Double check your ground wires.

 

"starts but immediately dies, every time. Runs for about 2 seconds and thats it."

In the old days this was an absolutely classic symptom of a failed ballast resistor in the coil feed circuit. Runs while on the "cranking" bypass position, then dies when the key is released to "run." Can you try hot wiring the coil?

Does it even have a coil...? ECU etc, I don't know . Too much magic.

 

I cleared the ICM codes, poured some gas down the throttle body, cranked it and it started. Stalled and I walked away. repeated the process, it ran and I drove it around the block for a half hour. I bet the ICM died, but did I need to CLEAR the codes for it to run?

These all still run the same. fuel, spark air.. WTF?

 

Chris, as stated above by "Rozcoking23" check your grounds. The ICM does not appear to have died or the engine would not have fired and certainly would not have run. Did you need to clear the codes for it to run, apparently yes. The P1361 code could certainly be caused by high resistance through a poor ground connection. The blown fuse could also be an indicator of a defective ground. The blown fuse also to a degree has me puzzled. Which circuit received power through that fuse? The OEM power distribution for your engine control systems (VCM, ICM, etc.) utilize either a 10 amp or 20 amp fuse so why is there a 15 amp fuse being used?

 

I had a similar issue with mine where it died and wouldn’t start back up. Once cooled down it would start and run again until warm and then die. Wouldn’t start again until it had cooled down a bit, ended up being the ecm temp sensor for me.
‘92 4.3l v6

 

The grounds on my jeep are a bit ridiculous. I used star washers and ran ground wires to everything. Im puzzled by the blown fuse as well. The fuse block that Howell used has al the same 15 amp fuses and they aren't labelled as to where they go, they just go into the pated up harness/loom.

I cleared the codes, it ran fine, the air horn fell off while driving, I put it back on, ran fine.. Yesterday I decided to take it to the store after I affixed the air horn better, pulled it out, got on the street and it ran as if the air horn was off, upsetting the MAF sensor.. I got it back in the garage and gave up. I will look at it today. Gremlins all of the sudden.

 

Do you have OBD1 or OBD2?

 

OBD2 I will plug in the scan tool and see what it reads later today. Yesterday it was time to just get it back into the garage and go have a beer. When this jeep runs well, its well worth the effort of the 4.3 swap over even the dauntless and absolutely over the 304. Mine seems to have issues, mostly me I believe. I'll get there.

 

Do you have a portfolio of pictures for your swap somewhere? I think some basic pictures of grounds, fuseblock, pcm, fuel tank, pump, filter, fuel line routing, distributor, temp sensor, throttlebody and intake sensors would help everyone. (I know it's a pain I haven't done it for mine).

 

Ha! no! When photo bucket went full idiot, I was done. I have posted pics of stuff here, but every single thing on my jeep is modified or fabricated. Frame, exhaust, body, body harness etc.. Its not a work of art, just a guy with a welder and a learning platform. If you want a specific picture or an idea of what I did and why, I would be happy to share it with you in a thread if you like.

Everything on the 4.3 is stock though. I left everything as it came from the factory. I used a modified stock astro /safari fuel pump cut into the 76? cj tank. Used Nicopp tubing for fuel lines and AN fittings.

 

figured it out.

This is a case of, use the diagnostic tools you own or get them and don't throw parts at stuff.

The jeep died because the ignition control module failed. It got hot and it killed it. Original to the engine. If I had read the code with my OBD2 reader, I would have known that, but instead I bought a new fuel pump. That was a mistake because that fuel pump only produced 20lbs of fuel pressure and my jeep needs 52 to even run.

Why was the full pump bad? Well, it could have been that it was a differnt type or that my connections in tank were not perfect and it created a sort of intermittent problem but the old pump was fine because when I put it back in, fuel pressure gauge read 52 with the key on.

Drove it around, runs great.

 

that’s the Dohicky inside the distributor right? My 231 died over the weekend kind of the same way. I checked for and found no spark this morning before work. I’m about to go outside and figure it out.

 

automotive term

 

On HEI systems it is in the distributor, on this engine it is external. They fail because they get hot. Make sure you use heat sink paste on the back of it when installing it.