Help! 96 ES dies when shift into gear.

[sassee]

My daughters' 96 'Trep ES is driving me nutz! It kept skipping and cutting off. I checked MAP sensor, no voltage on signal wire so I replaced it. I replaced both O2 Sensors. Now, it runs great....as long as you don't put it in gear! Put it in Reverse or Drive and it dies! (painfully) It acts like it wanys to go but stalls. If I give it some gas it will go but as soon as it slows down...........death!

It acts like my Toyota 4x4 when the clutch died. It was in gear and the clutch was depressed fully but it wan't to go! Could this be the torque converter not unlocking? If so, how do you test for that.? All help appreciated. $225 later and still not running! My teenage daughter is driving my Suburban!!! That's not good!!! I need to get her back on the road.

[theFREAKnasty82]

sounds like a fuel problem. Have the system pressure checked; if it's not at least 44 to 54 psi when running, it could be a bad pressure regulator or worse case, a bad fuel pump.

[sassee]

Originally Posted by theFREAKnasty82

sounds like a fuel problem. Have the system pressure checked; if it's not at least 44 to 54 psi when running, it could be a bad pressure regulator or worse case, a bad fuel pump.

It did have several codes from the OBDII scan. I don't have my norebok with me but one was "no 5 V. to MAP sensor and another involed being too lean and third was about idle speed. I replaced MAP and both O2 sensors (Upstrem) and it runs great until I put it in gear.

Would the fuel problem cause that? Like I said, it runs great and revs great until I put it in gear.

[sassee]

OK.....checked fuel pressure. 48 PSI running with vacuum on fuel pressure regulator. 54 PSI without vacuum on fuel pressure regulator. Fuel pressure drops when I apply pressure to regulator manually so regulator is working.
HELP!

[sassee]

BY the way...the codes from last week were:
P0171 System too lean (bank 1)
P1296 No 5V to MAP sensor
P1294 Idle speed performance

I replaced the MAP, both O2's upstream and fuel filter. It cranked and ran fine. I drove in arounf\d the block a few times. I erased codes and no more check lights on. I DID do the key on-off-on-off-on thing and keep getting a 12 and 55.
HELP! This car is about to meet Mr. Match if I don't get it running!

[theFREAKnasty82]

You mentioned that the code for idle speed driver: your normal idle speed should be around 750 RPM. Sounds like the idle speed motor is weak thus not allowing it to maintain the necessary idle when the engine's under load.

[sassee]

Thanks!

Is there any way to check short of just replacing it? At the rate I'm going, this will be a brand new car!

[sassee]

By-the-way......Does the "idle speed motor" have another name?

[theFREAKnasty82]

it can also be called IAC- Idle Air Control

[sassee]

OK.......IAC checked good. I actually took it out and verified it pulls in when turn ignition on. TPS sensor input and signal voltage good. Whats next

[sassee]

OK........Let the games begin!

After checking everything I could think to check, I went back and started over in case I missed something. When I got to the IAC, the voltages were DIFFERENT this time. I should have battery voltage on terminals "A" and "C" on the plug. The first time was 11.98 on both. when I re-checked them, I got .22 on "A" and 11.98 0n "C". Looked at wires for short, didn't find any. Checked voltage again, "A" was 11.98 and "C" was .07. Wait a little time and the readings are different. I don't know what "B" and "D" are supposed to be but they were different every time also.

What could possibly cause this? Is THIS my problem??? Still no Check Engine Light. Ran codes with OBDII, and nothing!!!

SOMEBODY PLEASE HELP!!! I'M LOSING IT HERE!!!

[theFREAKnasty82]

what I recommend that you do now is go to a shop or dealership (preferably a Chrysler dealer) who can hook up to the PCM and test it to see if it's working properly. If the sensors are good, that's an alternative route to take. If you want to save money, try this: disconnect the IAC again and get an ohmmeter and measure resistance. Measure resistance between terminals A & D and B & C; if you continuity at all, the sensor's fine, if one set of contacts have continuity and the others don't, you have a bad sensor and should be replaced.

[sassee]

The voltages I measured were from the plug itself, not the sensor. I read those volts from the wiring harness/plug with the plug diconnected from the sensor. It is supposed to be battery voltage at A and C. The voltages were all over the scale. No different scenarios, just lapse in time and readings were different. How does checking continuity on the sensor tell me what is happening with different volts on wiring harness?

Can dealership check PCM If I take just that to them? Closest Chrysler dealer is 50 miles and I'd have to have car towed (ouch)

[theFREAKnasty82]

the voltages confirm this for me, that the PCM is working properly b/c it has various drivers inside the module that control IAC movement; the purpose for checking the IAC itself will tell you if it can hold the signal needed to keep the motor going; a shorted out IAC will cause these same problems.

[theFREAKnasty82]

Here are a couple of other suggestions you might want to try; though your TPS never tripped a code, check it anyways: get a paper clip and attach it in the wire colored orange/blue and get your voltmeter (what you're doing is something called backprobing). With the key on, engine off attach the positive lead of the meter to that wire you've backprobed and the black to a good engine ground. Move the throttle by hand and you should see a smooth gradual rise in voltage; should go from 0.6v to 4.0V at full throttle. If it doesn't do any of those above steps, you have a bad Throttle position sensor and should replace it. Another thing, make sure your spark plug wires are snuggly in place and check the coil, make sure the primary ignition wires are not partially disconnected. Also, check around your intake manifold for any hissing or whistling sounds; make sure you don't have a manifold leak also check around your throttle body make sure it's snug and gasket's in place. Last, check body and engine ground connections make sure everything's in place; that could also be a trouble spot. Hopefully, I've been able to answer some issues for you and lead you in the right direction.