Engine Stuck At 3000 Rpm's

Discussion in '2.3L (N/A & Turbo) Tech' started by Matt E, Jul 10, 2014.

  1. Just bought a 1988 Mustang lx w/ the 2.3L engine. Owners thought the engine was seized and let the car sit for three years; but upon trailering it home found that the engine turned over, but the distributor was stabbed wrong and they had the firing order set wrong. After re stabbing the distributor, correcting their firing order mistake and replacing the plugs and starting the car with starting fluid i found that it was running high at 3000 rpm's. Can you guys give me a list of things to try?
  2. High RPM usually means either the IAC motor is stuck wide open, or you have a massive vacuum leak. Or the throttle plate is stuck open. Check other things first, but if someone has turned the idle set screw all the way in, I don't know if it would go that high, but that could cause an increased idle.
  3. Thanks, yesterday when I was playing with it, I actually set the idle screw to drop the rpm's from the 3000 range to around 900 while it was running; however, when I restarted the car it jumped right back up to high rpm's, the IAC has been replaced and the car still acted this way... HOWEVER people I know that also own an 88 mustang that had the same problem told me that it could be running extra hard to combat the engine feeling cold (they explained that this scenario would be caused by the temperature of the anti-freeze not being registered by malfunction, or lack of anti-freeze in the radiator allowing a cold temperature to be taken) they also suggested that maybe it could be a fuel problem from the fuel pump... coincidentally or not, today the fuel pump went out, wonder if tomorrow when I change it out if the rpm's might drop. A vacuum leak is a slight possibility same for the throttle plate. Thanks for you're time I'll keep you posted.
  4. First thing I would do when it's running again is check for codes. A bad coolant temp sensor should (hypothetically) trip one.

    Something else you can do is unplug the idle control valve and see what it does then. It should idle low or not at all.
  5. Thanks for the suggestion, today I replaced the fuel pump and started the car, was running around 900 rpm... sad part is the return line started spraying fuel because of a clip that broke after I got the tank back in... never seen a clip like it before and all the parts stores in my area thought I was crazy. Hoping these will work http://www.amazon.com/dp/B00066UKL2/?tag=stangnet-20

    Thanks 65ShelbyClone I'll post the outcome whenever I get the clips shipped in.