Crazy start up issue when Hot.

[1970pelle]

My 1989 1500 5.7L, 700r4, 2wd,. For the most part all stock. Just started this within the last 2 weeks. After first start of the day, if it doesn't start right up at the first hit of the key it will turn over. But there is no spark at the plugs or coil. There is fuel because you can smell it.
To get it to start besides letting it set for hours, all I have to do is disconnect both injector connectors. And it starts right up. Kind of funny, I was thinking a possible ground issue maybe ? Anyone ever had or hear of such a thing ?

(note) No fault codes, no check engine lite on.

Thanks Ken

[Cabnchassis]

Ground, coil, or distributor would be the places i would start to diagnose. There are a lot of ground wires on TBI trucks so be prepared to go hunting. IIRC there are 2 or 3 for just the ECU and junction block.

I would try to isolate function at the coil and see if you can determine it's input and ouput voltage but I couldn't tell you how to go about doing that. I research what I can, then just go outside and start taking stuff off or unplugging it until I find the issue lol.

I doubt the ECU can be involved beyond a grounding issue but it's worth noting that if you leave anything unplugged or have failed diagnostic devices to the ECU your truck will run like trash but its typically vacuum leak kind of running bad. As long as all the "info senders" are working well it's easy to find problems on this engine, cause pretty much all thats left is spark or air. . The oxy sensor, MAP sensor, the important of the two CTSs (one is ecu temp the other is gauge temp) I"m sure I'm forgetting more crap that adjusts the ECU but it's important to know that it is all performing correctly because the ECU will over fuel to avoid possible damage and make various other adjustments to maintain smooth operation. None of this is likely causing your problem but all of it can affect fuel mixture and idle making it really hard to find the real issue.

Sorry I couldn't be more helpful, good luck.

[1970pelle]

Thanks for the feedback. On the good side of things, I can duplicate the condition. So I'll check coil voltage for power as a input and a output. The Dist.
just by looks, I fail it. With the Dist. cap off the pick-up is rust and just looks plan nasty. The pick-up wires still have there insulation covering. The connectors at the ignition module has the tabs broken off, there laying inside the Dist. cap area.
If I wanted to throw parts at it, I would start at the Dist. with a Pick-up, module, new coil, new spark plug wires. I have already replaced the spark bolts(plugs). Clean and check all grounds I can find. I did find a salvage yard yellow marker, which they use to ID there parts. So its not the original engine, so very possible wiring harness issues. And who knows what else. It does run good other wise.

Ken

[speedygonzales]

My guess would be either a leaking injector or a leaking FPR. I'd start with the FPR. Unfortunately to test it you have to replace the filter with a test port.

[1970pelle]

I'm not having a lack of fuel issue. How I found out it would start after unplugging both fuel injectors. Is that it was still dumping fuel fuel while cranking over with what appears to be a no spark condition. I had the air filter housing top off to check for fuel from the injectors. I found the injectors firing so to speak(what ever you wish to call it) So to stop further flooding of the engine with fuel, I disconnected both injectors. Then had my son try starting again and it started right up. And its done this same deal several times now. And this is how I have started it each time. So I don't feel chasing a fuel pump or pressure problem is the correct way to go at this time.
Side note just after buying this truck I had the fuel tank down and inspected the new fuel pump module, and replaced the bad rubber hose connecting the pump to the sending unit.

But thank you for you time to read the post and your reply. Ken

[speedygonzales]

Leaking doesn't cause a lack of fuel. It floods the engine when you shut it down so that when you go to restart it, it can't cause it's got too much fuel. Then if it sits for a long time, the fuel evaporates and it will start normally. Get it now?

You should be smelling the oil to see if its contaminated.

Do a little research