1998 GMC Jimmy 4.3l Stalled out won't start


CanukGMC
04-18-2010, 06:46 AM
Bad day today, found a leak in my house and gallons of water flooded my kitchen floors overnight, get my wife to go into town to get me something and the jimmy stalls halfway down our road... gonna be one of THOSE weekends I see.

1998 GMC Jimmy 4.3l 4x4 auto


Engine stalled while driving. When I turn the key forward I have power, the engine cranks, the fuel pump "whines" for a second or two but nothing ever fires. Pretty sure it's no spark unless there's 2 fuel pumps in these things.

Any ideas of a good place to start?

old_master
04-18-2010, 07:25 AM
Wish I was in the Soo, but not with car troubles!

Check for a good blue, not orange, spark at each spark plug and at the coil wire where it connects to the distributor.

Fuel: There is only one fuel pump. Check fuel filter for restriction, located on inside of frame rail just behind left front wheel. Fuel pressure: Key on, engine off, fuel pump running, pressure must be 60psi to 66psi and must remain above 55psi for 3 to 5 minutes after the fuel pump shuts off.

CanukGMC
04-18-2010, 08:38 AM
Wish I was in the Soo, but not with car troubles!

Check for a good blue, not orange, spark at each spark plug and at the coil wire where it connects to the distributor.

Fuel: There is only one fuel pump. Check fuel filter for restriction, located on inside of frame rail just behind left front wheel. Fuel pressure: Key on, engine off, fuel pump running, pressure must be 60psi to 66psi and must remain above 55psi for 3 to 5 minutes after the fuel pump shuts off.

Thanks, I'll go tow it home in about 30mins and start yanking wires. Just so I don't fry some chip I'm un-aware of in this electrical eccentric engine, is it safe to unplug the wire that goes from the coil to the distributor AT the distributor and put a plug in the end of it to check for spark from the coil? I just don't want to short\fry something that I may be un-aware of in this engine, I only know so much about these old vortecs.

old_master
04-18-2010, 12:52 PM
Yes, you can check for spark from the coil by removing the wire from the distributor cap and install a spark tester directly to the wire. If you choose to use a spark plug to test for spark, open the gap up, it should easily jump a 1/2" gap and still have a blue spark. The only draw back to testing coil output using the coil wire, is if the coil wire is faulty, you won't know if it's the wire causing the no spark condition, or something else. Best to use a known good spark tester, instead of an unknown wire.

CanukGMC
04-18-2010, 08:13 PM
Yes, you can check for spark from the coil by removing the wire from the distributor cap and install a spark tester directly to the wire. If you choose to use a spark plug to test for spark, open the gap up, it should easily jump a 1/2" gap and still have a blue spark. The only draw back to testing coil output using the coil wire, is if the coil wire is faulty, you won't know if it's the wire causing the no spark condition, or something else. Best to use a known good spark tester, instead of an unknown wire.

Good stuff, been a long day here. I went back out to town the truck with a friend and decided to try firing it up again and sure enough it started without issue. It was a rainy morning and by the time I got back to it the weather turned to sun, I wonder if it was either a random gremlin in my electrical (this thing is riddled with those) or if there is a crack\leak in my distributor or coil causing a short when wet, I had this happen on a van I owned once, if you drove it and it started raining the engine would stall out like clockwork. I'll tinker with it and hopefully find something definitive.

viggy58
04-18-2010, 08:23 PM
well, glad it started up. it's always a pain in the ass having to get a tow...

CanukGMC
05-08-2010, 02:57 PM
Got a flat tire today in my driveway so I changed it out, when I inflated the tire I thought "hmm, better not run down my batt with this air pump" so I tried to start and sure enough, crank but no sputter or start.

Same kind of conditions, cold, a bit rainy\snowy out, etc. Hasn't been driven in a few days due to the flat. Pulled the wire off the coil at the distributor, nice solid blue spark (once it even grounded out through my thumb while testing it, good times). Fuel pump spins up, any ideas on where to check next guys? Thanks a ton

old_master
05-08-2010, 03:03 PM
Check for blue spark at each spark plug. If no spark at plugs, AC Delco cap and rotor is needed. If spark is ok, check fuel pressure. Key on, engine off, fuel pump running, pressure must be 60psi to 66psi and must remain above 55psi for 3 to 5 minutes after the fuel pump shuts off.

CanukGMC
05-08-2010, 03:06 PM
Check for blue spark at each spark plug. If no spark at plugs, AC Delco cap and rotor is needed. If spark is ok, check fuel pressure. Key on, engine off, fuel pump running, pressure must be 60psi to 66psi and must remain above 55psi for 3 to 5 minutes after the fuel pump shuts off.

Sounds good, the plugs on these engines are a -nightmare- to access. Think it's fair to say if I see spark at even 2-3 cylinders then theorectically it SHOULD at least sputter-run, so if I see spark at a couple plugs it's most likely fuel? Just thinkin out loud, real cruddy day to be out there busting knuckles.

While I'm on a slight rant, don't ever buy the crappy NAPA tire plug kits. The t-handle plug inserters are plastic and will eventually break, and it's usually when you are pressing hard pushing a plug in, when they break it will come apart in sharp peices cutting your hand up like you just broke a beer bottle in your palm. Yeah, 2x now.

old_master
05-08-2010, 04:01 PM
Weather dot com says 38 degrees right now, brrrrr says 51 for tomorrow, damn near Summer, might wanna wait ;) Easiest to jack up the front end and go through the wheel wells to access the plugs. Checking 2 or 3 plugs is a crap shoot, should check them all. If you're going to replace the plugs, use AC Delco. Aftermarket caps are famous for crossfiring in high humidity situations. If/when you have the cap off, make sure the vent holes are clear... two slots in the bottom of the distributor housing, right next to the camshaft position sensor. If they're clogged, condensation can accumulate on the underside of the cap. If it's excessive, you won't even get a fart when you crank the starter. Put a dab of silicone dielectric grease on each terminal, inside and out, of the cap.

CanukGMC
05-08-2010, 05:52 PM
Weather dot com says 38 degrees right now, brrrrr says 51 for tomorrow, damn near Summer, might wanna wait ;) Easiest to jack up the front end and go through the wheel wells to access the plugs. Checking 2 or 3 plugs is a crap shoot, should check them all. If you're going to replace the plugs, use AC Delco. Aftermarket caps are famous for crossfiring in high humidity situations. If/when you have the cap off, make sure the vent holes are clear... two slots in the bottom of the distributor housing, right next to the camshaft position sensor. If they're clogged, condensation can accumulate on the underside of the cap. If it's excessive, you won't even get a fart when you crank the starter. Put a dab of silicone dielectric grease on each terminal, inside and out, of the cap.

Thanks for the info, below zero where I am, perfect amount of cold for knuckle busting in the rain\sleet mix. Managed (and I do stress managed) to get a plug wire off, cost me a fingernail, not chipped either, full on busted, had spark at it, it wasn't necessarily a nice blue spark like the coil, more yellow\orangeish, but I was using an old plug left over from when I changed these things out a couple years back (worst job I think I've done on a vehicle, dropping the halfshaft from the steering column, removing half the stuff on the engine, JUST to do 6 plugs lol). I did clean up the plug best I could so I don't think it was dirty.

I ran out of starting fluid from working on my boat motor so I just dumped a couple ounces of gas down the throttle body, I opened it up so it would pour down the throat after I put some in. Tried cranking it and I actually heard what I would classify as 1 half power stroke, not even enough to get a rumble-rumble-cough-stall, more like a single heartbeat. Then the battery died so I can't crank it anymore until my other truck gets home.

I checked the shroeder valve (spelling?) on the back of the top of the engine, it spit fuel out when I pressed it with my thumb. I cycled the pump a couple more times and pressed it again and fuel spit again so I'm pretty sure at the very least my fuel pump IS moving fuel. That's about as high tech as I can get since I don't have a pressure tester.

My plug wires are crap. The one boot I did pull off had a bit of a crack in it. I wonder if one of them may be shorting, but you'd think being at the plug it'd just short the one cyl and make it run like crap\eat gas missfiring. This is a total DOA situation currently. Getting too cold and dark to tinker with it now, dead battery to boot.

Maybe something I listed here will unveil a key to the problem. I may pull the distributor cap off tomorrow and inspect it, but I am getting spark at at least one plug so it can't be totally shorted out inside of it. Thanks again for your insight, these vortecs drive me crazy, very complicated, and jam-packed-tight inside that engine bay, real pain to work on with my big gorilla hands.

CanukGMC
06-11-2010, 09:37 PM
UPDATE:

Changed the following- rotor, cap, wires, fuel filter, air filter (overdue anyways). Problem persists. Gave up. Brought it to the shop, it's been there for over 2 weeks... They keep telling me they're trying to figure it out.

Crank.
Spark.
Fuel pressure.

Won't start.

Doesn't even make sense, only way I can think to get crank, spark, fuel, and no boom is to remove the pistons from the engine. Any ideas I can throw at them while they bleed me dry?

old_master
06-12-2010, 07:45 AM
If it has fuel, compression, and spark at the right time, its got to start. Correct fuel pressure is mandatory on these engines, see post #2 for testing. Make sure the battery is fully charged so the pump gets good voltage to it while checking the fuel pressure.

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