Very hard to start, code 42

[Camatruder]

Hi guys, i’m having troubles diagnosing this code 42 (timing issue).

My truck is very hard to start, it needs cranking 30 seconds or more. When it finally runs, it runs and drives great as if there’s nothing wrong.

Battery voltage is good. I have good spark at all cilinders when cranking. Basic timing is set at 0° with the tan wire disconnected. I already replaced the ICM but that did not help. All 4 wires and connectors between the ICM and ECM are good (no shorts, no opens). Only thing, the ground wire (black red) is only grounded in the ICM, not in the ECM. Should it be and does that mean the ECM is faulty?

Or can it be something completely different?

 

[1987 GMC Jimmy]

42 is the EST bypass code. Just to verify, did you reconnect it when you were done setting the timing?

 

[Camatruder]

Yes i did.
Which makes me think i'm an idiot. The code 42 was probably stored because i disconnected the tan wire (BYPASS) to check my timing.
I should have cleared the code. I'll clear the codes, try to start it, let it run for 10 minutes or so and see if it throws any code.

 

[Camatruder]

Ok, i just proved my point about being an idiot. I put some fresh gas in and now it starts immediately but runs very rough and shaky. It did not throw any codes. So probably fuel filter or fuel pump. Hope i can score a filter here in Belgium or else i can wait for a week to get one from overseas. If so i'll order a fuel pressure test bypass also.

 

[1987 GMC Jimmy]

Ok, i just proved my point about being an idiot. I put some fresh gas in and now it starts immediately but runs very rough and shaky. It did not throw any codes. So probably fuel filter or fuel pump. Hope i can score a filter here in Belgium or else i can wait for a week to get one from overseas. If so i'll order a fuel pressure test bypass also.

Could be. I’d check for vacuum leaks to rule that out since you don’t need anything special for that. It’s probably got good spark, but it wouldn’t hurt to check the quality of it coming from the coil and the distributor cap. You can pull a wire off the cap and coil and hover a test light probe or even a screwdriver over both places while someone turns the key and see if you get a healthy, white spark. Otherwise, you’ll be looking at an electronic issue that’s sensor related or a fuel starvation issue. I’d definitely check for fuel pressure and replace the filter. Hopefully it’s something simple because I imagine it’s a pain trying to get American auto parts over there.

 

[Camatruder]

Well there are a couple of american car parts dealers here but i find them very expensive compared to ordering parts myself in the usa even with shipping costs included. The fuel filter on the other hand has metric threads and is used on a number of european cars also so i could pick one up here at a local shop. When replacing it i checked the fuel flow with the filter removed and it is absolutely not constant. The pump is making a harsh sound too so that'll be the cullprit.
Man i still can't believe i tackled myself with that code 42 i caused myself...Very weird though that it was hard to start but drove fine on a short test drive. What probably happened was that i was about to run out of fuel and eventually did which destroyed the pump. My fuel gauge is definitely not working as it should, that's for sure.
@Jesse, i did have good vacuum when it still was running fine and i checked spark quality with a tester.
Thanks.

 

[Snoots]

If you are going to replace the pump then, also replace the 'sock' or pick-up screen.
Another thing to consider if you have methanol-laced fuel where you are is to make certain that any fuel line in the tank is rated to be submerged in ethanol-laced fuel.
Some in-tank fuel pumps come with the fuel level sensor attached. If not you can clean the fuel varnish off with acetone or MEK. Don't use anything metal to scrub. An old toothbrush will do nicely.

 

[1987 GMC Jimmy]

If you’re going to the trouble to order from overseas, I’d just buy the whole assembly so you drop it in and don’t have to worry about it.

 

[Camatruder]

i'm about to order this one:
https://www.rockauto.com/en/moreinfo.php?pk=1063682&cc=1061570&jsn=459&jsn=459

 

[1987 GMC Jimmy]

If you haven’t already, I wouldn’t order that one. Airtex has an abysmal reputation with some of the members on here. I went with the Spectra assembly, and it’s fine. I’ve actually had good luck with their products so I’d recommend that one for your cheaper option.

 

[Camatruder]

Thanks! On the summit website somebody reviewed the Spectra unit and mentioned that the gasket was not included. I"ll order one extra just to be safe.

 

[1987 GMC Jimmy]

I hope it works out for you! That was probably just a packing error; the two I’ve bought did come with the gasket.

 

[Camatruder]

Just ordered, will arrive on monday, august 6.

 

[1987 GMC Jimmy]

Not bad. Good luck!

 

[Camatruder]

Well, the new pump is in and we're running strong again.
That was not a fun job to do on my own.