No Spark and no injector pulse

Scottls · 06-25-2015, 05:04 PM

I have a 1992 APV with a 3.1 liter naturally aspirated TBI that was running great a few days ago but then after spending a full day on a job and going out to start a cold engine, nothing! It cranks but wouldn't start. I checked for spark and then for injector pulse and from what I can see it isn't getting either. I had to have it towed home.

Two days later it started without fixing anything. I drove it to McDonald's only to be stranded again and having to get it towed home again. It seems that if it starts it runs fine like nothing is wrong but once I turned it off it wouldn't start again.

When I first noticed it wasn't getting any spark I changed the ECM and the ignition coil but no change. Then I noticed that the injectors were not spraying any gas either so I changed the fuel pump because I had to change it once before about a year ago when it wouldn't start. so now I installed a new one with a new fuel strainer and fuel filter. Still nothing!

When I first turn the ignition on I can hear the pump kick on for a few seconds and then shut off, just like it is suppose to. I also notice it comes on for a few seconds each time I crank it over so the fuel pump relay and all seems to be functioning all right.

The service engine light comes on when I turn on the ignition but it stays on while it cranks. I can't remember if that was normal or not. I know the computer is on but not sure if it knows the engine is cranking over.

This year of engine does not have a crank sensor (it still has a maniacal distributor) and no fuel rail or fuel pressure regulator. (I don't think) I'm thinking on changing the distributor for a new Cardone one because I noticed the harness plugs crumbling apart when I changed the ECM and this would also have a new pick-up coil and capacitor included.

Any other ideas any one?

Blue Bowtie · 06-26-2015, 07:08 PM

Even though the system uses a "maniacal" distributor the pickup coil and ignition amplifier module in the distributor must produce a trigger signal as a reference for the ECM so it can pulse the injectors.

Also, without this trigger signal, no spark would be produced. A new ignition module might be indicated, but be aware that a corroded pickup coil and/or reluctor can also cause this. There is also a semi-frail electrical connector for the pickup coil which can suffer heat damage and fail after about 20 years. It is easy to test the pickup coil with an ohmmeter. Expect to read around 350Ω minimum for a good pickup coil. Also make sure that there is no ground continuity at either pickup coil wire connection.

Scottls · 06-26-2015, 07:17 PM

Thanks Blue but I read another thread that also suggesting to replace the pick-up coil but that frail brittle connector was falling apart on both sides of the ECM so since I couldn't get a replacement harness for the distributor I bit the bullet and ordered the whole new distributor. That plus a new coil still cost me less than $100 new with no core charge! (Thanks Amazon Prime!) As soon as that all comes in and I install it I will post whether or not that fixed the problem.

I also want to thank Dan and LMP for the helpful tips listed in that other thread... (http://www.automotiveforums.com/vbul...ht=spark+pulse)

Scottls · 06-30-2015, 08:01 PM

OK, Sorry to take so long but I finally got the distributor installed (work has been keeping me too busy) and that's got it! It started up just fine. It did take a few minutes for the computer to relearn and smooth out but it's running like a champ again!

I know some might think I'm crazy to invest much into a 23 year old mini van but this one suits my needs just right and until it rusts out from underneath its plastic polymer shell I'm doing whatever I can to keep it on the road!

Thanks again everyone!

Blue Bowtie · 07-01-2015, 07:12 AM

Crazy? For under $100 you have transportation again. What might be "crazy" is hiring a cab for a day. That would get you a few trips and eat that hundo with nothing to show for it.

LMP · 07-03-2015, 07:35 PM

Great to see these legends still on the road. I'm just working to have my 3.8 1993 TS back and healthy on the road again...had a spark problem recently that would make the car hickup from time to time from loss of crank sensor signal....have to pull the front balancer/pulley to change the ck sensor....will report in a day or two....
I'm not in need of a totally reliable car now...just a "convenience" car that makes most jobs for day to day needs and occasional medium distance trips. if I need a long distance jump for a few days, I rent a car....sized for the exact purpose of the trip. Total reliability, minimum costs as this happens 3 or 4 times a year. For the rest, old TS totally fills the bill....

ifixalot · 07-16-2015, 08:17 AM

Glad to hear you found the problem. Mine had the same issue in the distributor
years ago. The wife got to our street and it died. What a good place for that to happen!
I just got done rebuilding the 3t40 transmission. I plan to keep it as long as I can.
The plastic body looks so much nicer than the rusted out junk I see on the road today.
I also read the 2002 to 2009 6 speed autos have wave plate that fails and kills the trans. I figure I'll just stick with what I got rather than chance a newer ride.

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