(If this is in the wrong subforum, I apologize)

I have a 1990 F-250 4x4 with the 7.3 and an auto transmission. Every once in a while, the truck revs out to almost 3K before shifting to second gear. The 2-3 shift is fine. It does this regardless of throttle position.

At first, I thought that it was b/c the vehicle was cold, but it did it today after an hour of driving. I also considered that it might be when the car was too hot, but some sub-30* days, it does it right after warm-up. It will be fine for a few days, then do it for a day or so, then fine, etc. Sometimes it does it only for part of the day. the only other info that might be important is that the temp gauge seems to be malfunctioning. It rarely (VERY rarely) reads in the "Normal" range, no matter how long the truck has run.

Any suggestions?

 

The engine temp gauges in the Dash on the early 90's trucks usually read on the low end or just inside the "Normal" range.

Your truck has got an E4OD tranny. The early E40D tranny's (89,90,91) were not very good and had a bunch of issues.

I would start with the obvious checks:

• Check your OD lit. If it is on or comes on intermittently it is trying to tell you there is a problem with the tranny.
• Ensure your tranny fluid is at the proper level. A low fluid level could delay shifting the way you have described it.
• Is the fluid nice and pink or look brown and smell burnt. If it looks like ATF then you are probably ok. If not change the oil, look carefully at the magnet in the oilpan for any metals - they are bad news.
• Have your tranny codes read by a professional tranny shop or buy an OBDI code reader and read them yourself.
• Are your Speedometer and Engine Tachometer Gauges on your dash working perfectly. The sensors that supply these instruments also supply the tranny electronic controller and if the instruments don't work properly then there is a good chance the tranny controller is not going to work properly and cause funny shifting or delayed shifting.

 

Thank you for your suggestion. I had NO odea which transmission I had, and I could not find an ID plate anywhere. When I went to aut parts stores, they said that due to the trucks of that year having multiple transmissions, I needed to call a dealership with my VIN to verify the transmission and proper fluid. I am sure that I need to do a fluid change, on top of everything else.

I just bought this truck a few months ago, and I am still getting acclimated to it.

 

look on the drivers door rear cab piller under the striker bolt. you should see a tag with all the truck info on it. copy all the numbers off that tag and let us know, and we can decode your truck. does it have a 3 speed trans, or a 4 speed?? it may just be something as simple as needing a trans filter/fluid service. when i buy anything the first thing i do is a full service on it, no matter what the previous owner says is new or not.

 

You have the same as my 90. You need to check for codes, and check the FIPL (TPS) to see if it is adjusted right. Do you have a manual for the truck? tjc might be right about the fluid change. I would start there. Don't just flush it, drop the pan and do it right. Do NOT use mercon 5 fluid. Also do not waste your money on synthetic, since you might need some other work, and you would loose the fluid. How many miles on the trans? Is it stock?

 

I will copy the tag today. I checked fluid levels and they appear in the normal range. For the last week, I have had no problems. It is very weird. Previous owner had a tranny rebuild (have receipts) at the dealership a few years back.

Truck is stock, and has 165K on the odo.

 

Next time you should try manually shifting the gears, see if it still happens to overspeed.

 

Sounds like a possible FIPL/TPS problem, but first I would advise checking all the electrical connections to the trans.........Since they are mentioned in the manual.

Check all the trans electrical connections especially the one on the right side with the tin cover, remove the tin heat shield, remove the solenoid connector by pushing on the center tab and pulling up on the wire harness. To install push down until a click is heard. Always reinstall the tin heat shield.

Your looking for corroded, bent or missing pins and water etc.......

Possible MLPS manual lever position lever out of alignment also.........

 

Sorry to bring back an old topic but I'm having the same problem with my e4od. I was wondering if you ever found the problem. I'm suspecting possibly an electrical problem. Since the problem is intermitant. I have scanned for codes and it comes back with none. If there was an electrical problem would it most likely generate codes? I had the transmission fluid changed within the last month and it was all clean and looked good. Any help would be greatly appreciated.

Again my problem only exists in lower gears. specifically from 1st to 2nd. Its seems to slip sometimes alot. I have adjusted my fipl using a volt meter and this doesn't seem to help.

The transmission is a ford factory rebuild with about 25k - 30k miles on it. I believe the updates were done since the rebuild was done within the last 5 years.

 

When my '90 started having intermittent problems similar to these it lasted about 40,000 miles before going into limp mode, the problem I finally found was the fusible link between the passenger side battery and fender, it had partially melted but would still make contact. After about a year it finally melted all of the way

 

Thanks I'll have to check that out. I know theres a bunch of wire going to that battery. Between the plow, dump hydraulics and backup lights. I drove it today and it worked like a charm. I'm really hoping its not my transmission it self. although that would be easier to find I think than an electrical problem...

 

If you got a poor power supply to the tranny controller or a poor ground connection then reading the tranny codes may not tell you much. You need to resolve power/ground issues first.

 

My tac won't read anything under 700, I also have the intermitant OD light. Trans seems to work better once it's warmed up and I've driven it awhile.

 

The engine tachometer sending unit is a common problem. It is located on the injection pump housing, drivers side of your engine oil filler cap. (1" nut with two black wires coming out of it).

Replacements unit are about $70. Fairly straight forward swap.

Note, the tranny needs an engine tachometer signal to control shifting.

 

Thanks, I'll look at it when it's cooler today.