Some new developments. The problem continues, but I am now zeroing in on some other symptoms. When the shifting problem occurs, I can smell exhaust inside the passenger area and at times the AC compressor will stop running. It now seems that whatever is causing the trans to downshift is NOT the trans itself. Could clogged cats or something else related to the O2 sensors have anything to do with it? I have cut off my mufflers and extended the tailpipes back. Normally there is no exhaust smell inside the cabin, but when the shifting issue occurs, I notice a strong exhaust odor. The problem also seems to occur when the vehicle is not warmed up, about 1/2 way home on my 20 mile trip, it will start shifting perfectly. The last hint is that it NEVER happens on acceleration, only while cruising at a set speed of 50-65 mph. As long as I am in the gas fairly hard, it pulls strong without hesitation. Any other ideas?
Need Help Please - Trans Problems!!!
- Thread starter ruswin
- Start date
The nightmare continues... I brought the car to Ford today (of course it drove PERFECTLY the entire 20 miles) and I assumed if ANYONE could figure this out, it would be them. After doing pressure test and checking for any engine codes or errors, he said they could not find anything wrong. He also said that because I installed a 98 trans in a 94, their scanner cannot "talk" to the trans? He suggested I take it to an aftermarket transmission shop because they have different scanners. I think it is bull:q:q:q:q, so I have no idea what to do next. The more time that goes on, the more it seems the actual cause of the problem is NOT transmission related, but the trans shifting is just one of the symptoms of the actual problem. Help? 
rayner601
Dedicated LVC Member
The nightmare continues... I brought the car to Ford today (of course it drove PERFECTLY the entire 20 miles) and I assumed if ANYONE could figure this out, it would be them. After doing pressure test and checking for any engine codes or errors, he said they could not find anything wrong. He also said that because I installed a 98 trans in a 94, their scanner cannot "talk" to the trans? He suggested I take it to an aftermarket transmission shop because they have different scanners. I think it is bull:q:q:q:q, so I have no idea what to do next. The more time that goes on, the more it seems the actual cause of the problem is NOT transmission related, but the trans shifting is just one of the symptoms of the actual problem. Help?
Last I remember, scanners don't "talk" to 4R70Ws...it's the PCM the scanner talks to and the PCM actuates solenoids or reads sensors
Do you have an oil leak? If so, check the harness that the trans is connected to. My 95 Cougar and 97 Mark 8 had oil leaks when I got them. The insulation on the wires fused together and caused all kinda hell...gear position data errors, rear o2 sensor codes, horrible shifting, blowing fuses when in reverse, no hazard flashers, no turn signals, auto lock not working, speedo not working right....
Thanks rayner601, the car is real clean underneath, only 64,000 miles and NO leaks. I would hope it is simple as that. Well I went ahead and dropped it of at another trans shop to see what they can find... I will let you know what is found in the end hopefully.
Need Help still... getting desparate!!!
This is an update. I have recently installed a new battery, alternator, ground wire, cleaned and reconnected all other main wires. That seemed to help a rough idle and hesitation, but did nothing to solve this problem. REFRESHER... While driving above 50-75 mph, the transmission will downshift to 3 and sometimes to second if my forward speed is low enough. When it happens, my AC clutch is also turning off momentarily which leads me to believe it could still be a bad TPS or a short or something giving the computer a WOT or similar signal causing the AC to shut off and the trans to kick down. My question is this, I have replaced the TPS already, what else should I look at? Where do the wires from the TPS go? What terminal on the ECU does it connect to? Is there any way to monitor the TPS signal while driving by using a volt meter in parallel? Any other ideas would be HUGELY appreciated.
This is an update. I have recently installed a new battery, alternator, ground wire, cleaned and reconnected all other main wires. That seemed to help a rough idle and hesitation, but did nothing to solve this problem. REFRESHER... While driving above 50-75 mph, the transmission will downshift to 3 and sometimes to second if my forward speed is low enough. When it happens, my AC clutch is also turning off momentarily which leads me to believe it could still be a bad TPS or a short or something giving the computer a WOT or similar signal causing the AC to shut off and the trans to kick down. My question is this, I have replaced the TPS already, what else should I look at? Where do the wires from the TPS go? What terminal on the ECU does it connect to? Is there any way to monitor the TPS signal while driving by using a volt meter in parallel? Any other ideas would be HUGELY appreciated.
NoLimit95
Dedicated LVC Member
Your idle problem is going to most likely be the IAC. It's next to the TPS but over to the left and has 2 bolts holding it in.
Your O/D problem is the 3-4 shift solenoid or w/e others call it. My 94 done the same thing. It only happened after the car warmed up but while it was cold, O/D would work perfect. It will eventually not have O/D at all. I'll show you a picture of mine and the hardest part about changing it was removing the Trans pan. The 3-4 shift solenoids are held in with 2 bolts and it plugs in. I changed mine in 2005 and I have had O/D ever since. Look below and you will see two silver boxes with black dots in the center. That comes all in one piece and it will fix your problem. Take yours with you to make sure the bolt pattern matches up. I learned the hard way that some parts stores carry them but bolt patterns do not. The cost of the part was around $60 and the IAC you need for a good idle will be around $65.
Your O/D problem is the 3-4 shift solenoid or w/e others call it. My 94 done the same thing. It only happened after the car warmed up but while it was cold, O/D would work perfect. It will eventually not have O/D at all. I'll show you a picture of mine and the hardest part about changing it was removing the Trans pan. The 3-4 shift solenoids are held in with 2 bolts and it plugs in. I changed mine in 2005 and I have had O/D ever since. Look below and you will see two silver boxes with black dots in the center. That comes all in one piece and it will fix your problem. Take yours with you to make sure the bolt pattern matches up. I learned the hard way that some parts stores carry them but bolt patterns do not. The cost of the part was around $60 and the IAC you need for a good idle will be around $65.
I am not ruling it out... and I appreciate ANY suggestions at this point, but why would the shift solenoids affect the AC clutch? I am looking for a common cause for the symptom of the trans down - shifting and the AC clutch turning off at the same time. Ford has no fricken idea what is wrong with it. 
NoLimit95
Dedicated LVC Member
OK, I'm just now catching on to the AC problem. Now that I see you have put in a 98 trans and having AC problems when the shifting things starts, scratch out what I said about the 3-4 shift. It still could be some of theproblem but your idle I can almost say for sure is the IAC. I had a bad idle and sometimes would kill out at the first start and then crank fine on the 2nd start but idled very low. I changed out the TPS and it made it better by 100 rpm's and then finally changed out the IAC and now I couldn't ask for a better idle. STarts up at around 1000 rpm's and then lowers on it's own down to around 700 to 750 rpm's.
turn_on68
Dedicated LVC Member
I am not ruling it out... and I appreciate ANY suggestions at this point, but why would the shift solenoids affect the AC clutch? I am looking for a common cause for the symptom of the trans down - shifting and the AC clutch turning off at the same time. Ford has no fricken idea what is wrong with it.
A/C shuts off because of higher RPM's, when you go above a certain RPM the compressor disengages to give more power, then re-engages after it shifts.
The IAC is about the only thing I have not replaced... what the heck... I will give it a try for the idle problem. I can live with a slight high idle but... it is the other crazy problem I still need to solve? 
The RPMs do not climb above 3000 even if it downshifts at 80 on the highway. I thought the only way the AC clutch is disabled is under WOT conditions?
The RPMs do not climb above 3000 even if it downshifts at 80 on the highway. I thought the only way the AC clutch is disabled is under WOT conditions?
The AC "shut off" is not RPM based
it's TP/Load based..the setting is "turn off AC at WOT".
Unless something is tellling the PCM he went to WOT the AC shouldn't shut off at "any RPM".
I'd test the TPS
At idle you should have between .9-1.0 volts on the signal wire
{usually a green wire) and 4.9 volts at WOT.
Once you verify these two voltages then you need an "analog voltmeter" to see if the TPS has any "bad spots".
Using a digital guage wont work in this case.....
You want a smooth sweep of the analog needle, from idle TO WOT.
If the needle jerks, hangs or otherwise doesnt sweep smoothly then you have a bad TPS {irregardless of the fact it's new).
If the TPS is bad and voltage is jumping around it'll make all kinds of goofy stuff occur.
If the analog needle makes a smooth uninteruppted sweep from .9V-4.99V then the TPS is NOT the issue.
That is correct
Thanks ALL!!! I will get an analog meter and test the TPS. I also was wondering if it is possible to tap into the TPS signal and actually watch it inside the cabin while driving? The TPS just has 2 wires, a 5 volt and a signal correct?
One more question... what do you guys do that allows you to be online all times of the day and respond to questions like mine?
Awesome... thanks!
One more question... what do you guys do that allows you to be online all times of the day and respond to questions like mine?
Awesome... thanks!
NoLimit95
Dedicated LVC Member
Correct but it could be causing his rough idle. It will have no effect with the 3-4 shift. Bad TPS, possibly but doubtful. 98 trans swapped into a 94, bad solenoids is where I'm leaning for some reason.
MLPS would be suspect before Shift Soleniods...IMHO
Might give it a shot to adjust the MLPS, it's been known to cause some goofy shifting stuff just like he describes.
I smoked my shift solenoids and the car only had 2 gear.
Might give it a shot to adjust the MLPS, it's been known to cause some goofy shifting stuff just like he describes.
I smoked my shift solenoids and the car only had 2 gear.
NoLimit95
Dedicated LVC Member
True too! His also seems to be different than mine was. I didn't have O/D after the car warmed up. From a cold start, I could drive 100 miles as long as I didn't have to stop and I would still have O/D but if I ever did stop, all I would have is 1st, 2nd, 3rd. I did buy a new MLPS first but it didn't do any good until I got the 3-4 solenoids and put them in. I wished that parts store was still open. He was one of the old school guys, about 70 that had been in business for 40 or 50 years and always had OEM parts but the chains eventually put him out of business.
I have finally been able to test and monitor the output voltage (0-5vdc) from the TPS inside the cabin. Here is how I did it.
http://www.lincolnvscadillac.com/showthread.php?p=575737#post575737
http://www.lincolnvscadillac.com/showthread.php?p=575737#post575737
This is like a soap opera, but maybe there is a happy ending. My AC clutch finally gave up working a couple weeks ago. After removing the pulley, it appears the clutch has burned up electrically also? (see photo) So I purchased and installed a brand new compressor, receiver-dryer and orifice tube. My hope is that since the shifting issue I have been experiencing seems to have occurred when the AC was operating, and since the AC cut-out at the same times that the shifting problem occurred, that somehow the shorting or damaged AC clutch could have affected the shift schedule or send a bad signal to the PCM? I have now driven it for only about 60 miles or so since the installation, so far so good. Time will tell if this really solved the problem. Check out the photo of orifice tube I removed from my "working" AC system, and the new one. Amazing how much crud accumulates and how important it is to change the orifice tube when possible... Using a small pick I ground down to fit inside the tube, it came out about the third try. I try to keep my AC working up to specs... especially here in Arizona where we run the AC 10 months out of the year! Keeping my fingers crossed.
kustomizingkid
Dedicated LVC Member
Holy crap!!
I know nothing about AC servicing... all my cars have had working ac, never had to dig in and fix it... yet
I know nothing about AC servicing... all my cars have had working ac, never had to dig in and fix it... yet
rayner601
Dedicated LVC Member
It appears that you have a failing compressor...
kustomizingkid
Dedicated LVC Member
Fixed that for ya...
Final Solution!!!
This is a follow up to this lengthy problem. I just hope this thread helps someone else someday. After replacing the melted A/C clutch, the car has run perfectly for about 2500 miles. No more shifting issues. How the burned up AC clutch could have possibly affected the transmission enough to downshift I have no idea? Thanks for everyone's help!!! Now on to the next problem... I cannot communicate with the computer to pull codes... that is another thread...
This is a follow up to this lengthy problem. I just hope this thread helps someone else someday. After replacing the melted A/C clutch, the car has run perfectly for about 2500 miles. No more shifting issues. How the burned up AC clutch could have possibly affected the transmission enough to downshift I have no idea? Thanks for everyone's help!!! Now on to the next problem... I cannot communicate with the computer to pull codes... that is another thread...