94 Blazer S10, 4.3Vortec Code42

[Dave_Calif]

The last couple days the car would start fine but would hesitate when accelerating. So I have been driving it hoping for a code. This afternoon I got a check engine light but the car died about a 1/2 mile from my house.

I checked the codes and had a 23 and 42. I had disconnected the MAP or whatever it is called on the air intake and it had fallen off, so I am assuming that is where the 23 came from. Anyhow as I was poking around I found the vacuum line that comes out from the Plenum off, so now I am thinking that is what was causing the hesitation.

So with that history the car will not start or even attemp to. I checked the fuel pressure since that is always most of my problems but the pressure is 60. I checked the spark off the coil and there is spark. I didn't get a chance to look for spark from the plugs because it was only me and I couldn't reach the key and watch for spark at the same time.

So I am thinking the car happened to die with the code 42 as a separate instance. Code 42 is "Bypass or electronic spark timing circuit - The EST signal did not change when the ECM applied bypass voltage to the ignition module".

I am enroute to Autozone to check the control module (I think it is called that; the module in the distributor).

Any other ideas or checks would be appreciated. Unfortunately the car is 1/2 mile away which makes troubleshooting it harder than sitting in the garage with Internet access. So tomorrow I need to go with lots of ideas.

Thanks...

[BlazerLT]

tuneup ever done?

[Dave_Calif]

Originally Posted by BlazerLT

tuneup ever done?

Yep less than two months ago, before I replaced the Spider as a last resort.

I brought the Ignition Control Module over to Autozone and it failed the second test (of 7 that run). Put the new one on the tester it ran. Went back and forth a couple times just to confirm. Bought a new one, stuck it in tonight thinking that was it, and it still doesn't start.

Back to the drawing board.

[Chris Stewart]

I had spark on a Camaro coil but it wouldn't light the plugs under compression until I replaced the coil.

[Dave_Calif]

Things have changed!!!

I towed the car home, and have been searching through threads looking for ideas. I now think it is the Spider, and I think I might have screwed up the one that was in it.

The problem started with a hesitation. The other day I put a can of Chevron Techron Injector cleaner in it as I was filling it up. I am now thinking that screwed up the Spider, but I don't really know for sure. Maybe 10 miles after I put the injector cleaner in, it died on the way home and hasn't started since. I found a vacuum hose off later, which I think could account for the hesitation.

In any case I have pressure of 62 at the fuel test connector. After the pump stops it drops to 56 and only drops 2 every few minutes. I think it had that pressure when it was working fine.

I put starter fluid in the intake and it starts for 10 seconds or so until the fuel runs out. So it tells me the electrical and spark are fine, thus leaving fuel. I don't get a smell of fuel, and although I haven't taken the plenium off yet from what I can see it looks ok but obviously I can't see that much.

I just replaced the spider two months ago (although it isn't under warranty as I had a spare one) so I kept thinking it had to be fine, but now I have myself convinced it has to be bad since it starts with fluid in the intake and the pressure is there. Could I have gummed something up with the Injector cleaner?

Is there anything else I may be overlooking other than the spider? I have thought about this so much I think I may be missing something obvious since I just replaced it.

Thanks
Dave

[ericn1300]

It's an ignition error. Go back and clear the codes and see if any reset when you try to start it, that will take any missgivings you have about the codes out of the picture.

[Dave_Calif]

Originally Posted by ericn1300

It's an ignition error. Go back and clear the codes and see if any reset when you try to start it, that will take any missgivings you have about the codes out of the picture.

I've cleared it and when it does start for 10 seconds it doesn't get a another code. I think the 42 was from the ECM as it definately failed in the tester. I went back and forth with the new one and bad one on the tester a number of times to confirm in my mind the original was bad. It failed one test every time out of seven tests on the original.