Tylerjp

Hi, I have browsed this forum and several other websites looking for possible answers to my issue. I have a 1995 F150 Regular cab long bed XLT. It has the 300 inline 6 with a e40D transmission( only 2WD) automatic. I have been having an issue with the truck when I put it into gear( any gear whether it be reverse, drive or 2 or 1) that the truck will shift and then the engine will stumble very quickly and die, sometimes it does catch itself otherwise I have to throttle through it. This happens after I let off the brake pedal and let the truck engine become under load, if I keep the emergency brake on it will continue to idle just fine and not stumble. I have done everything I have come across on the internet for this common problem. The PSOM is fine, I did replace it, I have checked the solenoid pack, I have adjusted and replaced the range selector, made sure the linkage to the transmission was good and tight. Ruling out the transmission I moved to the engine, it idles and revs perfectly. I have checked for codes and get none with the OBD1 system. I have swapped the MAP sensor with another, I tried swapped throttle bodies with new Idle sensors. Thinking that it could be vacuum, I have checked all the vacuum lines(it is missing some emissions stuff but it ran fine before without it). I have tried a new ignition module and coil but I still have the same problem. I have also pulled the battery cable to reset the computer and make it relearn the system but still nothing has changed. Any thoughts or possible solutions would be much appreciated. Thank you.

Good old Bill

After reading the long thread, issue is the engine stalls, hesitates, or even dies upon engagement of trans. Inspect all vacuum lines for obvious defects. A vacuum leak will cause quirks that the engine control module cannot correct immediately. Am really surprised that the check engine is not talking to you.
Get back to us.

Tylerjp

I have done that also, it does have an emissions delete, dropped the pan of the trans and replaced filter, checked fuel pressure and spark, all is fine. Even checked the egr. Still having the same problem. Also replaced the spark plugs. Also still throwing no codes from the engine and given that the truck is obd1 the transmission can' communicate with the "computer".

justintendo

what fuel pressure readings did you get?

Tylerjp

Running it bounces around 53 to 55 and key on engine off at 50

raski

If you have a vacuum gauge(a valuable tool to have), make sure you have 18-22 inches and steady at idle. Usually if you have a major vacuum leak, RPM will go up but not always. As you are checking vacuum at idle, raise the RPM and hold, vacuum should briefly drop and go back up. If it drops low and stays there with the engine speed up, you have an exhaust restriction.However, I am suspicious of vacuum issues since it is fine with the emergency brake applied. I would apply the e-brake, let it idle and at the same time, apply your brakes. If it dies, look for a leaky brake booster and/or vacuum resevour(?). Both are easily tested.Hope this helps.