After the engine gets warm and in park...the engine will stall then surge back to idle speed about once every 10 seconds. If your sitting in drive with your foot on the brake...it does not occur. While driving, the car will run fine under load, but if you are coasting it will stall and completely lose power until you pop it into neutral for a second...then it starts running again... :roll:
How many miles are on the car?
Have you checked for vacuum leaks?
Have you checked for codes?
Does this car have a MAF sensor or throddle body that needs to be cleaned?
This car has a vane metering system (VAT/VAF), but the problem sounds like the idle air control valve, since it only happens when the throttle is at idle.
"sleepdog" wrote: > This car has a vane metering system (VAT/VAF), but the problem > sounds > like the idle air control valve, since it only happens when > the > throttle is at idle.
It has 95,000 miles on it...it does not have an idle air control valve (CFI 1.9 L). I have checked for vacuum leaks...
My bad, assumed it was MFI like my old Escort. For CFI check the idle control motor.
You know...you may be onto something there...I have watched that thing and I never see it move...
1990 seems a bit late for CFI? You sure?? The CFI's used an "Idle Tracking Motor". One common failure was the "nose switch" in the tracking motor asy. that sensed when the throttle was closed. I don't remember the symptoms, but if the nose switch was bad it caused an bad idle concern. The motors used to fail on a regular basis also. I remember a few CFI cars with shorted?(full hot) coolant temp sensors that mimiced tracking motor concerns. (No or low idle until the CTS was unplugged).
The CFIs were made up until the 1990 model year, you could get them in the AT LX and Pony trims. 1990 was the last year for the 1st gen Escort, 1991 and forward were the 2nd gen Mazdas that I think were always MFI.
"Tom Adkins" wrote: > chum wrote: > > "sleepdog" wrote: > > > >>My bad, assumed it was MFI like my old Escort. For > CFI check the > > > > idle > > > >>control motor. > > > > > > You know...you may be onto something there...I have watched > that > > thing and I never see it move... > > > > 1990 seems a bit late for CFI? You sure?? > The CFI's used an "Idle Tracking Motor". One common failure > was the "nose switch" in > the tracking motor asy. that sensed when the throttle was > closed. I don't remember the > symptoms, but if the nose switch was bad it caused an bad idle > concern. The motors > used to fail on a regular basis also. I remember a few CFI > cars with shorted?(full > hot) coolant temp sensors that mimiced tracking motor > concerns. (No or low idle until > the CTS was unplugged).
If CFI means "central fuel injection" then that?s what it has...one injector that sprays into a throttle body.
Does the temp guage on the dash have anything to do with "coolant temp sensor" If it was shorted wouldn?t I have the symptom constantly...it does not happen when the engine is first started...it has to run for about 10 minutes before the problem starts...
The dash temp guage is connected to its own temp sensor in the heater tube behind the head. I wouldn't worry about that, it has no affect on the car's computer.
The coolant temp sensor that sends a signal to the computer is right next to the temp guage sensor, in the same heater tube. It's a real PITA to replace unless you take the intake manifold off, which I would not recommend anyway.
10 minutes? Maybe an EGR component??? Hard to say on my end.I would scan for codes and post them back here. You can pick up a scanner at Sears for $20 or go to autozone and have them do it for free. I have an alldata account that I can reference to get some insight on any codes you might have stored.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.