1991 Cadi Fleetwood ISC Motor Questions

countchocula79 · #1 (**permalink**) 09-26-07, 11:43 PM

I have a 91 Fleetwood, i was wondering, when my vehicle is shut down, even for a long period of time, that damn ISC motor continues to ratchet, not loud at all, in fact i have to put my ear up to it to hear it, is it supposed to do that, also i have a problem where she starts but then shuts down after a sec, but starts again on the second try, thanks for any suggestions

**Ranger** · #2 (**permalink**) 09-26-07, 11:56 PM

No, it is not supposed to do that. It is failing and that is why it dies.

jamesmdx1 · #3 (**permalink**) 09-27-07, 12:24 AM

does the isc motor do the same thing after shutting the engine down for a 88-89 4.5?

**Ranger** · #4 (**permalink**) 09-27-07, 12:39 AM

Not sure, but I think so.

haemka · #5 (**permalink**) 11-23-08, 04:14 PM

I have the same problem when starting und shutting down the ignition. What can I do?

**Ranger** · #6 (**permalink**) 11-23-08, 04:59 PM

Have someone start the car while you watch the ISC plunger. If it retracts and stalls the engine, replace it.

haemka · #7 (**permalink**) 11-23-08, 06:03 PM

The plunger does not retract, it moves sometimes in and out, and there is no gap between the plunger and the throttle positioner

**Ranger** · #8 (**permalink**) 11-23-08, 09:26 PM

Might want to get a fuel pressure gauge on it and make sure you have good fuel pressure. Yours might be a failing fuel pump.

chubbyranger · #9 (**permalink**) 11-24-08, 02:53 AM

Quote:

Originally Posted by haemka

The plunger does not retract, it moves sometimes in and out, and there is no gap between the plunger and the throttle positioner

The ISC on my 1990 used to twitch after shutdown, but only for a few seconds. It never really affected anything and the car ran fine so I just lived with it. Is yours causing a problem?

haemka · #10 (**permalink**) 11-24-08, 04:06 AM

Yes, the problem is, when I press the gaspedal to start the car, the first moment happens nothing but than it accelerates heavy. Cruising is no problem and the fuel consumption is also ok.

**Ranger** · #11 (**permalink**) 11-24-08, 11:35 AM

No need to press the pedal when starting on a fuel injected engine. That's an old outdated carburetor method. Try starting without touching it.

haemka · #12 (**permalink**) 11-24-08, 04:06 PM

Sorry, It is a missunderstanding. I don't press the pedal when I start the engine.
I mean when I driveaway the car. For the first moment there is no acceleration, so that I have to press the gaspedal very very slow, to avoid that the car makes a jump. By the way, the ECM Trouble Code is 49 (Air injection Reaction system fault.

**Ranger** · #13 (**permalink**) 11-24-08, 05:30 PM

That sounds like it might be a bad TPS.