Mechanics

MERCURY MARQUIS COOLANT PROBLEM

1987 Mercury Marquis • 124,000 miles

Needs some ideas to check. Only after the car warms, it will sputter every now and then. It is very intermittent. Also, it will sputter on deceleration and some times even stall the car.
Things changed already:
plugs, wires, fuel filter.

The air filter is clean. The throttle body is clean. IACV seems to be working properly and is currently being cleaned. Also going to check for vacuum leaks. Is there anything I am missing to inspect? Thanks
Avatar
Cjstafford
March 21, 2013.



Could this (Picture) be the culprit?


Tiny
Cjstafford
Mar 21, 2013.
You cannot clean the iac valve. It has to be replaced if not working correctly.

Look for coolant leaks around wires going down to plugs. Intakes are common for this type of issue with running

Roy


ASEMaster6371
Mar 21, 2013.
Oh, I read you could clean them. My bad. I verified it is working correctly. There were no air leaks. The water pump is shot and leaking straight out of itself. Before I found this out, I did a fuel pressure test. A guy from Ford said there should be 35 lbs of pressure and there was only 28-30. Also, the pressure did not change as the throttle increased. Seems to be a bad fuel pump to me. I did not get a chance to see if the coolant was leaking on the plugs though. What do you think?


Tiny
Cjstafford
Mar 21, 2013.
How did you check the IAC to determine it is working perfectly?

I would look at the plugs, wires and coil.

Fuel pressure is too low

Roy


ASEMaster6371
Mar 21, 2013.
I don't know that I can say "perfectly" but is is working. The idle is off without it plugged in and controls when it is plugged in. Is not a proper way to determine that? Plugs and wires have already been replaced.


Tiny
Cjstafford
Mar 21, 2013.
With it disconnected, the idle should be 500 rpm, not shut off.

Roy


ASEMaster6371
Mar 22, 2013.
Sorry, I meant off from normal and then it fixes itself when it is reconnected.


Tiny
Cjstafford
Mar 22, 2013.