I have a 1997 Chrsyler Sebring Convertible, 2.5L V6, that starts, revs to about 3000 RPM, and dies, here's what's been done to it;

First the car had no spark, no fuel, no nothing,
Connected scanner, no communication with the computers, read 'CCD Buss Inactive' checked the buss wires, had 2.49 on the +, 2.51 on the -, checked the connections, found a dirty connection on the heater mode door, cleaned that, and could communicate with all but the engine computer

Read the pins on the computer, the 5v feed to the TPS, MAP, and A/C switch read to ground, found the MAP sensor was shorted, replaced it, disconnected the battery for 10 minutes to reset the computer, but the computer wouldn't come back on.

Replaced the PCM, which had been a 1259AG with a 1259AI out of a wrecked 1997 convertible with the 2.5L engine, the PCM allowed me to program my car's VIN into it, whether that was because it had been out of service for so long, or what, I don't know.

Car started, but would rev high, then die, checked the fuel pressure, that was low, replaced the fuel pump, pressure is good, but car still revs and dies, car starts, scanner shows it's going to about 2900 RPM, then the fuel is shut off, IAC goes from 135 to 0, looked for an air leak, car would start with the intake blocked, so there's air getting in somewhere, had a friend start the car with the intake blocked, sprayed starting fluid uner the plenum (I'd checked all the vacuum hoses by this time) car would continue to run as long as I sprayed fluid under the plenum on the passengers side of the engine, replaced the plenum gasket, no change, so I replaced the intake manifold gaskets, also replaced the plugs while I had the plenum off. Car still goes to 2900 RPM and the computer shuts off the fuel, but, the car will no longer start with the intake blocked off, which is something. Rechecked all the vacuum lines, replaced the IAC, no change, disconnected the EGR tube from the plenum, blocked that, no change. Reran all the function tests with the scanner, everything is working, but the car still acts like it's getting way too much air, I can't find anything that shows the new computer would be making the engine rev, besides, I have the throttle cables disconnected. I've even tried blocking the IAC holes, but that makes no change.

This car has had the closest thing to the automotive equivalent of a nervous breakdown I've seen lately, it's got me totally frustrated, the car sounds fine during the brief time it runs, so I'm not getting into the timing belt yet.

Anyone had this problem, or have any ideas, I'm stumped

Randy

 

WOW...you have a live one.....(or a dead one, however you look at it) I'm guessing, if your fuel pump is shutting off then something is telling the PCM the engine is not running. Did you check the air in the tires ? Just kiddin'. A chilton's manual will explain all the sensors and curcuits, I would start there. But it sounds like you know what your doing, stay focused and you'll get it.

 

Well, there's progress (btw, I'm using Mitchell On Demand 4)

I blocked the IAC input port outboard of the butterfly in the throttle body, car now idles, so there's something in the IAC, I've removed, cleaned the plenum, and replaced the IAC, so I've got to fix that, but the car still dies, so it's not the computer thinking there's an overspeed, BUT.... I put a VOM to Pin 74 on the computer, which is the fuel pump relay feed, it shows 12v when the key is turned on, but goes to zip when the car starts, Auto shut down relay is good, any thoughts? I'm hoping it's not another dead computer, but, from what I can see, the computer just passes 12v to the FPR from the ASD, am I right?

Randy

 

Your talkin' way over my head...I'm just a dumb hic from Tennessee...I fix cars with a repair manual, a scan tool, and a garage full of nice tools. You are talkin' another language to me. It sounds to me, like you have a Masters Degree in electrical engineering. I do better with my hands then learning from a book. I can't help. My guess is that you'll stump even the most informed Chrysler service tech.

 

While I appeciate the reply, sort of, I've got a scanner, a manual, and all kinds of nice tools also, but, as I said, I'm stumped, maybe I'm wrong, but I detect a note of sarcasm here. Guess I came to the wrong place for some assistance.

 

I didn't mean no harm...It was a bad attempt at a joke...I never had to dig that deep into a project before, nor do I have the knowledge to do so.

 

Hi Rogue. I have a similar problem. 94 GTC with the 3.0 It ran great last fall and I put it away for the winter, put sta-bil in, removed the battery, etc. well I put the battery back in and tried to start it up, it did start right up but only runs about 2-3 seconds and dies. It acted like no fuel so I replaced the fuel filter and checked the fuel pressure (70 lbs) Then I put a noid tester on and it flashed for the 2-3 secs that the car ran then nothing. Anybody have any ideas?

 

The usual scenario when a car starts but dies after a couple of seconds relates to the anti-theft system. Does your car have that feature? If so, it may be the source of the problem. You might also want to check the ASD (auto shut down) relay.