I've been dealing with this intermittent problem for a while now with my 95 Pickup 4X4 22RE.

The truck has three "modes" it runs in.

Mode 1 - Runs perfect. No issues. Good power, starting etc.

Mode 2 - Check engine light comes on. Power cut significantly. Still runs and drives, albeit poorly.

Mode 3 - Engine stalls. Check engine light on. Will not start...unless I crank the heck out of it and floor the gas pedal, then it slowly sputters to life



When these different modes occur - I notice mode 2 and 3 happening more after the truck has sat for a while. They seem to go away after driving for some time, like an hour or so. But during that hour, there could be any combination of mode 1-3 for any amount of time.

It can go from not starting at all, to running perfectly. For example, one time it stalled completely. I called a tow and had it taken to my indy shop. After a while I get a call to say that the truck is running perfectly, they could find nothing wrong. This is before I discovered that flooring it when starting could usually nurse it back to life. So it can go from not starting at all, to an hour later, starting and running perfectly.



Things that don't seem to correlate:

- Engine RPM. Can happen at any RPM

- Road speed. Can happen at any road speed

- Throttle position. Can happen from full throttle to idle and anywhere in between

- Engine load. Happens under any engine load.



Things that do seem to correlate (MAYBE, I'm not totally convinced of the correlation)

- Seems to happen after truck has been sitting for a period of time. The longer, the worse it is

- Seems to go away after the car has been driven for some time. Like today, after a lot of issues and multiple stalls, it went away. I was running a lot of errands all day.



Code I captured one time when I caught the engine light on long enough for me to test:

Code 25 - Air–Fuel Ratio Lean Malfunction

Note that it has been a while, and I'm going by memory. I thought when I looked it up way back then, the descriptor said 'intermittent lean condition', but when looking at the manual now, I see that code 25 says the above. I may have remembered something wrong but I'm pretty sure I remember 25 as the correct code.



So, what component can intermittently malfunction, then go back to normal? Sometimes causing a lack of power, or a total stall. Sometimes preventing from starting unless I floor the pedal and crank a lot. Other times, the truck runs flawlessly, all within the same drive. It can rapidly shift between the three modes at any time and any amount of times, but eventually if I have a long enough driving session, the issues go away...usually...I think.



When it completely stalls (and before I figured out how to start it with pedal floored) I would seem to detect the smell of gas while endlessly cranking. Same for right after I would nurse a start out of it with the pedal floored.

The truck always starts fine on the first start of the day.



I looked at my records because I thought I had replaced the O2 sensor, but I don't see anywhere that I did so. In 2011 (and not that many miles ago) I removed and sent the injectors out for rebuilding.

EDIT: I replaced the O2 sensors and the problem has vanished!! So happy about it. I'll add that the bolts were so frozen and corroded that I gave up after about five minutes of trying and took it to a muffler shop, They weren't sure if they could get the old ones off or if I'd have to order new (aftermarket) flanges to be welded on. Well, they succeeded in getting the old ones off. I started to drive home with some trepidation (and not a little PTSD from the stupid check engine light flashing on and my power cutting), but after about ten minutes of driving, I was pretty confident the problem was gone. After the half hour drive to make my way home, no issue. I was thrilled, to say the least.

 

Fuel injector failing or stuck open, Could be a problem with a stuck open cold start injector. The tell tail here is wide open throttle cranking will get it to start when its running bad. Wide open throttle shuts off the main fuel injectors to clear a flooded engine condition.

 

Got info. I will keep that in mind if the O2 sensors don't fix it. O2 sensors could probably use refreshing after 27 years of use anyway
Just to clarify, in case it matters, flooring it isn't a magic bullet. It BARELY sputters to life with a lot of cranking. But with no flooring, it absolutely will not start for quite some time.

 

I am betting on something time/temp related. It always runs fine first start because it is cold. The shop couldn’t see a problem after it had cooled off. I had a Honda like that. The water temp sensor was failing but still within the range of operation so when it hit a certain temp, it would suddenly tell the computer it was like 20*F outside when it was 70 out and kick the idle up high, stall, and not restart until it cooled.
test your sensors hot and cold.

 

SOLVED!!

Solution back in the original post

 

wrong window