Bad injector?

[hermitjohn]

Last two times I started 94 Ranger with 4.0L OHV engine:

1.  On cold start, it would start and die, took several times until it would stay running, and rough when it did.  When it warmed up a bit it acted normal, idled smooth, though power seemed bit down warm.  No codes.

2.  On cold start, it started normally, idled smoothly.  Thought it somehow cured itself.  I was just moving it short distance to shady area.  Shut it down. Decided it needed to be in slightly more in shade and this time it did the start and die and rough idle routine.  No codes.

I ran across similar symptoms in google search.  One guy replaced MAF and cured.  Frankly every problem seems to get blamed on MAF and the MAF on mine looks new and tests ok with voltmeter.  And other post suggested a sticky injector.  

Ok, injector makes sense, guessing it sticks closed at times when engine is cold.  

I  can buy reconditioned set injectors on ebay for around $60 so guess thats worth a try.  Just looking for somebody to confirm that injector is reasonable guess.  This truck has little over 190k miles. No idea if or when injectors replaced/cleaned in past with different owners.

[Deleted]

I think it's a reasonable guess.

Have you tried putting some ATF in your fuel? That's a trick DH learned when he worked as a wrench for some local good ol' boys. Might buy you a little time while you decide on the reconditioned injectors.

[hermitjohn]

I had to move it today thinking ups truck was going to make a delivery. They left my package at neighbor.... But I am not so sure its an injector. Today it felt more like maybe TPS, though its relatively new and motorcraft brand. I need to spend some time tinkering with it and thinking about it.

[hermitjohn]

I think its either gotta be bad injector or yet another wonky ECM (computer). And after looking around the cheapest set refurbished injectors were set sold for a early 90s Dodge v8. They are exact same Bosch injectors, same Bosch part number, just priced significantly less than same set sold for Fords of that era. I really hate greed. I really hope it is the injectors. At 190k miles no doubt not hurt to replace them. I would guess previous owners neither replaced nor professionally cleaned them. Though engine is mechanically in great shape considering the miles on it. And its cheaper to put set refurbished injectors on than to hire existing ones cleaned and flow benched. LOL, will even have couple spare ones....

[hermitjohn]

I went to replace the injectors, removing plenum part of intake manifold. But as I was disconnecting stuff, saw big vacuum leak, there was a vacuum port that had been plugged with short bit hose and something or other in the end of the hose. It had come out. Plugged it with a bolt and after that, it idles well.

So didnt finish replacing injectors. Though thinking I will anyway in cooler weather since I now own them, just to see if it does make a difference. And lot miles on truck. Will keep old set too since it runs ok with them now.

I am noticing what sounds like an unbalanced driveshaft, but only after truck been driven a while and only at lower speeds. That part annoys me, I get to town and start having the unbalanced thwump-thwump. But I am on my way home and it goes away, even at slower speeds. Grrr, hate the come and go problems like that, but just has to be driveshaft. Definitely not some engine misfire.