I have recently purchased a 1997 4x4 ext cab w/ 120k. It has the 4.6 and the 4R70w tranny (I think..it has " U" on doorjamb). I degreased the motor yesterday and it ran like trash all the way to work. (3 miles each way) and after work to an auto parts store to pull the codes..misfiring cylinder #8. I bought and replaced plugs and wires. Runs good again but tranny shifts really hard from 2-3 and when you come to a stop it nearly dies like the TC is not releasing as the truck rolls to a stop. Also when you slow down it is hesitant to downshift and lugs motor for a while when you try to re accelerate. This morning I shifted it manually on my way to work as the missing cylinder was worse at low RPMs and engine RPM were low. I thought maybe the tranny "learned" goofy shifting because I held it in lower gears and let it rev higher but disconnected battery and shifting issue still remains. The truck always shifted a little hard from1 to 2 but the person I bought it from said he had a performance tranny shop do work on it 2 years ago and I though made they put a shift kit in it. Could I have done something like damage vacuum hose or unplug something while I was installing plugs and wires.....the ones by the firewall was a treat. :-) Will battery disconnect "un-learn" the tranny? Seems like too big of a cowindie dink to not be related.

 

First thing you done wrong was degrease the motor and cause yourself problems with the ignition.

The trans may have very well been reprogrammed to to harsh a level but you won't be able to tell unless the valve body is removed and inspected.
With all the other ways the trans is acting you need to have it gone over anyways.
There is no getting around it any easy way.

 

Who knew the grease was helping it run smoothly. :-P

I am trying to see if the TPS or another sensor can do the symptoms.

 

I drove and got Autozone to pull the codes....still nothing (execpt the EGR P0141) that has been there. If I hurt the TPS with water would that throw a cose to the OBI scanner AutoZone uses?

 

Update....I went at lunchtime to local indep. tranny shop. they put a Snap-On scanner on it and no codes. The guy drove it and said the TC is locking up WAY too early and not releasing..that is causing the shudder when truck rolls to a stop. I think his scan tool showed if TC was locked/unlocked. He also said the brake should unlock the TC automatically and it had no effect. I noticed if I manually downshift it into 1st as the truck gets to about 10 MPH no shudder as truck stops...might mean nothing..might be a clue to those who know more than me. He recommended pulling pan and draining TC..which he did. Oil and pan looked totally clean..like operation table clean....almost too clean like someone just was just in there. (recall I just bought truck a little over a week ago) . Of course he said for a cool $1600 he will rebuild tranny and new (reman?) TC. I am hesitant because other than a slightly firm 1-2 shift I had no issues prior to this(although it was only a week of driving) I am now scared to drive it....if the TC is coming apart it will get ugly fast.

 

Your at a point the trans shop can't tell anything more with out taking it apart.
You have to go ahead and have it fixed or you just waisted your money buying the truck.
Did you not road test the truck before you bought it?
I'm not trying to be a hard *** but you bear some responsibility for this.
Go back to the seller and see what they say.
Good luck.

 

1st off, use an air compressor and blow off the entire engine. Use a nozzle and get into the nooks and crannies, especially around the spark plugs / coils / etc. Really dry it off good. This should help with the stumble and misfires.

2nd, take a good, close look at the connectors going to the tranny. Disconnect them and clean them with a quality cleaner that displaces water.

Re-assemble and let us know what happens...

Good luck !!

 

I did test drive it and although it shifted "slightly firm" 1-2 it had no issues other than that . Plus the guy said he had a performance rebuild~ 1.5 yr ago and I figured they bumped the line pressure thru a shift kit at that time. The truck fine for ~ a week prior to my "washing" it.

 

That's a big clue. When the shifter is in manual 1 there is a hydraulic circuit that forces the torque converter to unlock. Apparantly that is working, so the torque converter clutch is working and the converter clutch valve in the valve body is working.

That means that the problem is almost certainly the torque converter lockup solenoid, or even more likely, the wiring to the solenoid. If the wire to the solenoid is shorted to ground the converter will only release in manual 1st and reverse.

Cleaning the connectors to the transmission is a good suggestion.

 

I talked a guy @ Baugham (they build a lot of trannys for Mustangs) and he told me what wire from the ECU controls the TC lockup. I am going to try to remove that wire from the harness plug to disconnect it and put a volt meter on it too see what the computer is telling the TC to do. Then I will know if it is in that circuit at least and not a mechanical issue.

 

I re-cleaned the connector at the transmission and followed it up to main harness on pass. side firewall. Took the connector apart and removed the purple/yellow strip wire from the plug. I think that should have made the TC never lock up. I drove it and it acts the same...I put a multi meter on the computer side ad I get resistance (although higher then I would have expected) when I think it should tell the TC to lockup....high speeds steady throttle..and then throttle to idle /coast or brake on makes circuit go open. If I start truck and put it in 2nd and not "D" or 1st the truck almost stalls. I suppose the wiring from the firewall connector could be grounded yet...I am out to check that.

Update: when I test the TCC lockup wire at the firewall connector it is "open" to ground....I expected it to be the TCC solenoid value.(whatever that is but ~10-20 ohms I bet)

 

I dropped the pan and removed the TCC. It measure 1.6 ohms. I also broke the connector clip that makes sure it stays attached...aaaahhh my day/weekend has been like this. I think I can use a very small wire tie to serve same function when i re-assemble. But I digress. I also read somewhere you can put +12V across it and it will click...which i did in both polarities...nothing. Maybe a TCC?

 

Update: I replaced the TCC and it solved the issues. I guess it was locked "open" mechanically and allowing the TC to enter lock-up. Thanks a million to all those who offered advice/assistance.

 

How much did that set you back because I think I have the same problem??

 

Ponycar. The TCC was like 30 bucks from a "buy it now" off eBay. I actually was going to purchase it from local Ford dealer but was out of town for work during the week and couldn't get to a Ford Dealership. Be aware there are at least 3 different types TCCs and ypu must get the right one. Describe what your symptoms are and I will try to help.