Motor Stumbles??

[CHARLIE]

I first posted this thread on the sedan area by mistake. Sorry bout that.
My 87 Quad. with 2 liter F.I. engine has a problem with dying when a small amount of throttle is added. It is especially bad when the engine is cold. If I push the throttle down about an eight of an inch it feels like the ignition has been turned off. With a hard throttle there is no noticable problem. It runs great except below 2000 RPM.
When comming to a stop sign if I let off the gas normally, it dies. If I gradually decrease the throttle it is OK.
The car is totally stock and only has 40K miles.
Any ideas??

[MrT]

Have you thought of a sticky air flow meter door? Or a dirty rheostat assembly under the AFM cover? Worn contacts might have an area of poor response. I suspect you could monitor the resistance of the assembly as you open the door manually to verify this.

You might also want to check that the Throttle Position Sensor is properly adjusted so when the throttle opens by the spec. amount, it no longer tells the ECU that the throttle is closed. Disconnecting the TPS connector _might_ be a workable test, but I don't know whether the failed response is to assume closed or not-closed.

Just my 2cents worth.

Michael

[John M]

Hey Charlie:

I will add to what Michael said and suggest also checking all the rubber and hard intake plastic hoses as well as the vacuum hoses. Look for cracks in the mating surfaces of the hard hoses. Also look for tears/cracks in the flexible rubber intake hoses.

Best Regards,
John M