1993 4.0 No Start

[LG57]

Thanks for the suggestions Ken. The rough running happens either hot or cold. Doesn't seem to change with temperature. It does have a new thermostat and hoses plus fan belt. The old thermostat was stuck and causing it to overheat. So I flushed the system and put in the new parts. Now it runs at normal temp.
Where are the temp sensors? Maybe as you say the one for the computer might be a problem.
Also the exhaust system seems ok. no leaks or whistles. I'll tear into that as a last resort. Could be full of dirt daubers!
Today I went ahead and ordered a set of injectors from Ebay. Should have em in about a week.
The ones I cleaned seemed about the same as the new one on the spray pattern, but as I understand it, these have a small filter basket in the top which I was not able to service.
I just don't have a lot of confidence in the cleanup job.

 

[kmack]

Warm engine shudders and runs rough at startup.

This post explains the two sensors and their location.

 

[LG57]

Ok, I'm back with an update. Replaced both temp sensors and noticed no change in it's bad habits. Still hesitates when hitting the throttle and misses/noses over if full throttle is applied when running down the road. Also, installed the six new injectors with no change.
Question: I'm taking the battery out of another car in order to test this thing, then putting it back at the conclusion of the test. Does the computer need to learn while driving to get it's parameters tuned in? If so, am I not giving it a chance to learn and retain settings by removing the battery?

 

[MrQ]

It needs about 50 miles of driving to relearn engine habits again after removing/replacing the battery.

 

[Turdle]

It needs about 50 miles of driving to relearn engine habits again after removing/replacing the battery.

It should still drive with most if not all power. Problem is not fixed.
To the OP:

Have you tried checking the throttle position sensor?

 

[LG57]

Thanks. Looks like it's time to get it's own battery.

 

[LG57]

It should still drive with most if not all power. Problem is not fixed.
To the OP:

Have you tried checking the throttle position sensor?

What would be the procedure to test that?

 

[Turdle]

What would be the procedure to test that?

How to: - Ford Explorer - Ranger TPS Test Procedure

 

[LG57]

Thanks for that. I'll test it asap!

 

[LG57]

Ok, TPS checks out at .92 to 4.59/4.6 volts with no skips or bumps as the throttle is moved.

 

[Turdle]

Ok, TPS checks out at .92 to 4.59/4.6 volts with no skips or bumps as the throttle is moved.

Ok, that's good, and it can be ruled out.
Next suspect in line ( just my opinion) is the maf sensor. have you cleaned it? Sometimes merely unplugging it to see how the engine runs with it out of the loop will help determine if it is out of calibration-whacked.

 

[410Fortune]

30 psi rail pressure is a little low?
Clean the MAS for sure Jon may be onto something there
Check intake hose for cracks, the hose between the airbox and throttle body
Have you burned through the old fuel yet and added new?

 

[~X~]

30 psi rail pressure is a little low?
Clean the MAS for sure Jon may be onto something there
Check intake hose for cracks, the hose between the airbox and throttle body
Have you burned through the old fuel yet and added new?

Air filter too, especially if it's 17+ years old.

 

[LG57]

The MAF and throttle body have been cleaned. It has new fuel (about a month old at this point). New air filter. Fuel filter has been changed twice since the fuel pump was replaced after cleaning the tank of old jelled gas. Don't see any cracks or leaks in the plastic hose between air box and throttle body.
How can I check the MAF for correct function?

 

[MrQ]

It should still drive with most if not all power. Problem is not fixed.

Never said it would fix the problem . I merely answered his question about the relearning process of the computer.

 

[LG57]

Success!!! Progress report today. Finally got back to working on this thing after a lot of other "stuff" got handled. It had a fuel leak on the rear drivers side injector. I cut an o-ring when I installed the new injectors. Got that fixed today. Then turned to the MAF. I thought I had cleaned it as stated above, but that was not true. I first unplugged it and the stumbling and missing went away! Ran great. So, I cleaned it with MAF spray cleaner and it runs much better! Still has a slight hesitation off idle, but I'm going to call it good for now.
Thank you guys for all the advice. It appears the MAF was the final key to getting it running right. Now on to sealing the quarter glass and cleaning the interior and recovering the headliner.

 

[LG57]

I have a new issue. After backing up, then shift into 1st gear as the car starts to move forward there is a deep buzzing sound for a moment. Anyone experience this? It doesn't happen again until you back up then go forward. There are no tire rubs. There is no noise from the throw out bearing. Ideas?