I got my engine rebuilt about 500 miles ago and has since had some starting problems. In the morning or during a cold start the engine starts up relatively normal(cold start inj. is working fine).
Once the engine is warmed up and its shut off for more than a couple minutes it cranks for 3-8 seconds before it starts(slight stutter for only a second upon initial start up...seems like its running rich). Once it starts up it idles and runs perfect...doesnt smoke or do anything strange besides the rough warm start. Its got new plugs,wires, dist, etc(from rebuild) I just ordered a set of injectors from LCeng...Any more ideas?Im running out. Thanks

 

Mine does the exact same thing. Itll bust off first thing in the mornings great, after its run for the day, cranks for a little while and when it does begin to start, it runs rough for just a bit and after a bit starts running good again. Ive got my engine out right now doing a major on it, will see how it goes when I get her back together. Ill keep an eye on this thread, might be something helpful in here for me too!!!

 

Try the fuel pump test jumper:
- http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

My '85 had that sort of hard start problem a few years back and it was the Circuit Opening Relay not kicking in while the starter cranked.

 

Thanks 4crawler, ill check it out.

 

Jumpered the test plug and the fuel pump starts right up and the truck starts how it should. Somewhere its failing to turn my pump on when the ign is on...where should i test next? Thanks for the help!

 

Lookin into the COR now...its probably the culprit... im hoping

 

Exactly what mine was.... I'd stop after driving around, wouldn't start for a while till it cooled down. Reached up and almost burned my finger on the C.O.R.. Replaced it in the O'Reilly parking lot(Kragen at the time, lol) and voila, solved.

There are other hot soak culprits, but that is the most likely one to check, first.

Probably could get one at a yard(pick-u-part) for 5$. I know, a new one at the parts store is more 'sure' a fix....but just saying, if you have one near ya.

 

Thanks Chef...hopefully narrowed it down to that. well c.

 

Well i ordered the circuit open relay(85910-14020) and hopefully that'll fix it...

 

I've got the exact opposite issue. Slow cold start but fine when warm. Hints? A friend said something about losing pressure in the fuel line because of old seals??

 

Might be worth checking out your COR also...have you checked out your cold start inj?

 

I have not. What are the steps to checking those two for issues? My brain started to freeze up when I got into 4crawlers link.

 

Well, the fuel pump test jumper is the first part of checking the COR. It will make it turn on with the ignition and run the fuel pump prior to the starter cranking over. If it helps, then follow the COR troubleshooting info on the web page link, if not, it is probably the cold start injector or time switch.

 

Like i said(which isn't always an option, I know).... ask a buddy without issues to lend you his COR, pop it in and try it out/rule it out. OR< hit the Junk yard and yoink one.......... which I only mention cuz you can't return electrical parts, most often.

Hoping it solves the issue for ya. If not, we dig deeper from there, right? What else can you do?

 

COR is on its way...$30 on ebay... i checked the resistances on the old COR and everything seems to checkout except i wasnt getting an open circuit on the Fp. i get 12v when cranking and running

 

Well, don't break anything if it doesn't solve it, ok?

Question,.... when you turn the key over when it's hot, do you hear that POPPING/CLICKING in the glove box area? The COR makes a pretty distinctive click. Of course, you wont notice if it's NOT unless you're hot and trying to start it hot. But, when cold, you could go out there and give the key an ALMOST start position and see if you hear it. I don't think that's conclusive though, as the thing might be opening for a portion of it's duty, but not allowing a complete circuit when it's time to start under hot conditions?

 

the COR clicks faintly (barely audible)when i turn the key on but if i turn the key while holding the COR in my hand i can feel it. The click is much more distinctive and audible when i turn the key away from the start position...

 

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Well, did you try the fuel pump test jumper? If not, do so and see if it makes any difference.

Looking back, I see you mentioned that and it worked intermittently. Now w/ new COR, there must be something else going on. Either the current from the relay is not making it to the pump (see if you get any variation in pump voltage when it runs and does not run with the jumper in and the ignition on). Or the power feeding the COR is intermittent, if so, find out why. And don't forget, there are two sides to the circuit, power (12 volts) and ground. Both connections have to be good to have a complete circuit.

 

^^^ Listen to the Guru, Sir! lol

I thought you'd done that.... don't have time to read back ,...fill Roger in?