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Hello, I am new to this site and have just purchased my first diesel. It's a 1992 F-350 crew cab, 7.3l. I bought this truck knowing there was shifting problems with the transmission but I got it real cheap, hoping it is something sensor related. The transmission runs fine in 1st then it shifts hard to 2nd but when it shifts to 3rd it shifts hard back to 2nd then to 3rd and so on, until it reaches a point where it shifts to drive and then it runs ok there and in OD. I just drove it about 5 miles to my house and parked it, so I don't have much information. The ABS light and the Brake light are on. Could this be a ABS or Speed Sensor problem that is making it not know what gear it should be in. Sorry I don't have anymore information at this point. Can anyone get me started in the right direction. A list of items that may cause this or a list of items that wouldn't cause it would be helpful. Thanks
Hey man, sorry to hear about your rig. There are several different sensors that you can peek at. Have you looked at the FIPL at all yet? If its gray then it should be replaced due to the gray ones being known to fail. It should be replaced with a new black one.
I had a chance to drive it for a few miles down the road today and it almost seems to shutter back and forth between gears. At one point it seemed to go into neutral for a second. I can manually shift from first to second and it does fine. The FIPL is the grey one. I guess I need to start by replacing it. Does anyone have any more suggestions?
Buy,beg,borrrow,rent a OBD1 code reader. Follow the directions on how to use the code reader to retrieve the Key On Engine Off codes. Replace or re-adjust what is called for by the retrieved codes. Perform another KOEO test, same as before. If everythings reads good, then do a Key On Engin Run test and see what other codes are shown. Repair or replace what is called for by the codes. Perform the KOER test again. If there are only good codes then you are set to go. Good Luck. Jim
Acording to the in fo PLC7.3 gave me I black is the old style and should be replaced with the grey. Not sure if that would cause the problem But he should be along in a bit with some advice.
Acording to the in fo PLC7.3 gave me I black is the old style and should be replaced with the grey. Not sure if that would cause the problem But he should be along in a bit with some advice.
You are correct the black is the old one....I was going from memory, I should have just looked under the hood....
If it goes into neutral at random, it is probably related to the connection (MPLS?) on the drivers side of the tranny. Try searching on here for similiar issues, it may help guide you.
Well, I hooked up the scan tool and tried to ferform the scan but the scanner kept saying must plug tool into the DLC. I checked for loose wires in the connector, sprayed contact cleaner in the connector and checked the connection several times but I could never get it to connect to the scanner. Any Ideas of what may be causing this?
After driving the truck more it seems to have more of a slipping into neutral and slamming back into gears than it does, changing gears eratically. Supposedly the transmission was rebuilt about 20,000 miles ago. The fluid level is good and it looks and smells ok.
So I decided to start replacing sensors. I replaced both the MLPS and the VSS and they did not help. I have the FIPL sensor but have not had time to change it yet. If the FIPL does not work, are there any other options other than take it to a tranny shop?
Did you have both connections going to the scanner? From what you are saying I would have put my money on the MLPS, but it seems I would have been wrong.
Was there any warranty on the supposed tranny work?
Another way to find the codes is to connect a light to the connections and count the flashes. Thats all mine basicaly does anyway. Yours seems pretty high tech comparatively......
FYI mine is an Actron CP9015 I got it at O'Rielly Auto Parts for like $25.....it seems to read codes fine. It uses a 9 volt battery though.
I just thought of something but I don't know if it would be related or not. I have never seen a check engine light come on. Even when I turn the key on. It may just be a blown bulb. Could the scanner not reaching the computer and the check engine light not working be connecting in any way?