95, 3.8 liter tranny problems and CEL

[Android_Gimpy6456]

Ok I bought this van 6 mos. ago and while I was looking at it it blew a lower radiator hose. Not good right but the wife HAD to have it so we bought it. They fixed that but it still overheated after a few quick fixes and finding the fan relay (found that by accident by the way) replaced it and replaced the temp sensor underneath the throttle body. (That was a pain in the a** by the way, pay someone to do it) It still want to get hot while sitting for a while, finally figured out you have to leave the defroster on for the fan to keep working, it even turns on and off like it suppose too. Now for the fun stuff. (1) When throttling really hard (like passing) the tranny will kick out of gear and rev. real hard in D or in (D) both times it will do that. But it slides back into gear ok no hard shifting or clunking. (Something to do with the TCC?) I did a trans service new fluid and filter and it still does it but it does shift better. (2) Very rarely while going down the road for an extended period of time with the cruise on, it will just die on me. No warning it just dies. But if you pull over and put it in park and restart it, it acts fine any TAKERS.
(3) Lastly my CEL comes on and off at random, the computer plug only has three metal contacts in it. I tried crossing them but still the CEL wont blink when I turn on the key, is there a trick to this and if so what did you use to cross them and what tabs did you touch together? Autozone told me it was OBD1 so they cant read the codes, but I still need to figure out what codes are being pulled. (4) I was gonna ask about the wiper thing but I think from previous threads I have the answer.

Thanks A bunch:
Carl E Weisenauer

[Android_Gimpy6456]

Can ANYONE help me with this??

[LMP]

95 is not "flash" readable like 93 ..and '94 may be maybe not. Flashing the codes needs contats A and B in the computer plug....

There are codes readers that are "OBD1" compatible...they are more expensive.

Fans: when you use the DEF position, as well as DEF/HT mix, A/C is trigged on at same time and then fans come ON. This is because a/c acts at same time as dehumidifier and this helps clearing the fog. I do not like that A/C be energized without my own consentment...and in my other cars, where this cross action is from a mechanical switch, I have disconnected it. With this one, is comes from the computer....so have to live with it.
Yes..temp sensors are positioned in the worst place they could find. Just below throttle body is the 2-wire computer temp sensor...the one that should enable starting the fans when it gets hot. THere is another 1-wire sensor farther back just for the indicator....So....while these are generally sturdy and correctly matched, there is no absolute garantee they tell same temperature.

About transmission shifting: downshifting when pressing hard is quite normal....this engine does not rev easily over 4500 rpm...so between 2nd and 4TCC, there are several gears: first, TCC comes off as it stays in 4tn gear, then will shift to 3rd....may be it will shift to 2nd is slow enough....I'm not sure '95 has a throttle cable to the transmssion..but there is a vacuum modulator...a leak in the vacuum feed to modulator can make it downshift much easily as loss of vacuum is like depressing the throttle to the floor...so if it really seems to downshift in an abusive manner, check for that...and eventually, for the modulator itself.

[Android_Gimpy6456]

About transmission shifting: downshifting when pressing hard is quite normal....this engine does not rev easily over 4500 rpm...so between 2nd and 4TCC, there are several gears: first, TCC comes off as it stays in 4tn gear, then will shift to 3rd....may be it will shift to 2nd is slow enough....I'm not sure '95 has a throttle cable to the transmssion..but there is a vacuum modulator...a leak in the vacuum feed to modulator can make it downshift much easily as loss of vacuum is like depressing the throttle to the floor...so if it really seems to downshift in an abusive manner, check for that...and eventually, for the modulator itself.[/quote]

Ok I didn't explain the tranny prblem well enough. I understand that downshifting is common when you pass, but my van dosen't down shift it just simply shifts into neutral without actually kicking the tranny into neutral. (Ok imagine driving a standard and while you go to pass someone halfway through the passing manuver you step on the clutch and the engine just revs.) But when I let off the throttle it will slide back into gear as pretty as you please.(I've never experieced this before in my 10 yrs. of working on cars never, not once it makers me think that the bands or clutches are bad for passing but the tranny otherwise works just fine (for the most part)

[LMP]

OK..understand. Easy causes are low fluid level, clogged transmission filter....then I would try to determine condition of the transmission modulator : when throttle is down and vacuum goes to near atmospheric pressure, the modulator must increase oil pressure in transmission to keep clutches from slipping: a dead modulator would maintain low pressure and induce slippage when engine torque is high. THis is the last external component but after that, everything is possible....I would not like it either.

[Android_Gimpy6456]

Originally Posted by LMP

OK..understand. Easy causes are low fluid level, clogged transmission filter....then I would try to determine condition of the transmission modulator : when throttle is down and vacuum goes to near atmospheric pressure, the modulator must increase oil pressure in transmission to keep clutches from slipping: a dead modulator would maintain low pressure and induce slippage when engine torque is high. THis is the last external component but after that, everything is possible....I would not like it either.

Well according to autozone and napa this part dosen't exist on a 95 Lumina APV which is extremely funny, BUT on a Pontiac Transport there are modulators so... Does anyone have this part on there 95 3.8 4 speed tranny or did some morrons put a Transport tranny on my Lumina van. If so could this be the cause of my tranny problems? And what am I to expect, is there any differences, gearing, TCC the electric computer managment, I'm a mechanic but I'm not a mexican mechanic (no affence intended) but we've all seen really studid S*** on vehicles.

[LMP]

Check Rockauto.com and modulator is alive and well for both '95 Xport and APV. Autozone info is interesting but lacks year specific details.

[Android_Gimpy6456]

Ok yet to get the modulator so I'm not sure if thats the problem yet, seems autozone wont sell me one because it "dont exist" for my exact model. If I do buy it for my van which is a 95 LUMINA APV 3.8 what would I ask for exactly, I'm gonna go to Marion and get it so if I dont need it they'll take it back. TADA