Contour Enthusiasts Group Archives Forums General Troubleshooting Mystique w/ 2.5 stalls accelerating, uphil

My friend's 1995 Mystique with the 2.5 and auto tranny is stalling (badly) when accelerating normally. Same thing when going up any kind of hill at all.

Runs fine at idle, and runs fine on level ground at constant speed.

I have replaced the fuel filter, no help.

It has a brand new set of plugs in it.

I also put a new Mass Airflow Sensor on this thing (on advice from AutoZone) but that didn't seem to help it at all. I did not , however, unplug the battery (to reset computer ?) when i put the new part on .. should I have ?

I have never had a check engine light.

I've also checked the fuel pressure, seems to be at about 40 lbs which I belive is about right.

I'm running out of ideas fast.

The temperature is running in the normal range, on the cool side, even on the hottest days.

Thanks for any ideas,

DLD

ps i'm not familliar with some of the acronyms i'm seeing here (iac?) so spell 'em out if you don't mind

Welcome onboard.

Don't think I can help with ideas on core problem, but here's a little info.

Common acronyms from FAQ section:

http://www.contour.org/FAQ/FAQ.cgi?s=terms

For some reason the most common, CEL (check engine light), isn't listed.

Reset PCM by pulling fuses f9 & f11 in engine compartment fuse box for a few minutes, easier than disconnecting battery.

F9 and F11 or F6 and F11 ? anouther post on here said F6

thanks !

DLD

bit of an update, i put the jumper on so i could check the computer codes and it says i have an EGR valve not operating properly

anybody else have trouble with these before ?

dld

Way to go on the jumper test! This is a great feature of the 95s! What code did you get? A 332 is pretty common if you have clogged up EGR ports. These ports built into the upper intake run from the EGR valve to the main air intake just behind the Throttle Body. You can clean these with throttle body cleaner and a soft rag once you remove all the intake stuff and the TB. Also check for cracks in the green plastic vacuum hoses leading to the EGR valve and other components.

i got a "33", then anouther "33" then a 1 , then two more 33's

this one seems to use 2 digit codes rather than the 3 digit codes i've read about.

DLD

i'm planning on just sliding a piece of sheet metal down between the intake and the EGR to see if that is indeed the problem, to cap it off (the intake)

any reason that won't work ? if it quits this stalling crap i'll assume that's whats wrong and either clean or get a new EGR valve.

DLD

I'm pretty sure this will set a constant CEL as you will completely block the EGR passages. The PCM knows from various sensor points what the EGR flow situation is and will complain if it's not correct. (i.e. CEL) The OBD 1 computer has different codes, but yours should be the same as mine (95 'tour) I don't have my haynes manual with me, but will look up a 033 code when I get home. (THe 95 codes are different than these: http://contour.org/FAQ/FAQ.cgi?s=probs&display=checkengine )

Might want to double check/recount the CEL flashes to make sure you have right code. The EGR may be causing the CEL, but usually will not cause stumbling like you mentioned. Might want to double check that the plugs are tight, that each cylinder is firing at idle and higher RPMs, and that there are no intake leaks etc.

i never get a check engine light

i got those codes when i did the jumper thing to start diagnostics, and i looked up the code value on a generic EEC IV web page i found .. so it should be a valid code

i belive the EGR is stuck open, and it should *run* fine with the egr blocked off at the intake. i'm not going to leave it that way, it's just an easy way to check if that's my problem or not .. block it off, go for a ride, see if it still stumbles.

i'm postive on the code, checked it many, many times and i get the same code with the key on, engine off test and with the key on, engine on test

DLD

bounce