New issues after head gasket... - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Speedway · 11-14-2005, 01:33

Well not exactly new, but persisting. I have finished doing the head gasket on my EA but aside from fixing the water disappearing problem, some of the original problems are still present. Prior to pulling the head, the old girl was drinking fuel like it was going out of style and running rough as guts. After reassembly it is still doing that, even on a new set of plugs. All 6 plugs are jet black and she is running ultra rich. I am going to replace the dizzy cap and rotor tomorrow but is there anything else I should be considering?

Cheers
Bruce

madmelon · 11-14-2005, 04:48

Well I'd be betting on some sort of fuel rather than spark problem to begin with, thought it is possible. Perhaps oxygen sensor- they actually do die after a certain time (constant heating and cooling) or maybe throttle position sensor, MAP, something else like that.
As a car gets older everything inside the engine wears out and so allows slight air leaks, thus reducing vacuum in the manifold. This gives the car a signal that it's under more load than it really is, so oversupply of fuel occurs. Falcons already run rich, so this would just make things really bad. Same deal if the TPS is telling the ECU that the throttle is open when it's not.
There's probably other things too, but that's basically all I know.

tufLTD · 11-14-2005, 05:53

Quote:

Originally Posted by Speedway

Well not exactly new, but persisting. I have finished doing the head gasket on my EA but aside from fixing the water disappearing problem, some of the original problems are still present. Prior to pulling the head, the old girl was drinking fuel like it was going out of style and running rough as guts. After reassembly it is still doing that, even on a new set of plugs. All 6 plugs are jet black and she is running ultra rich. I am going to replace the dizzy cap and rotor tomorrow but is there anything else I should be considering?

Cheers
Bruce

Check the vacuum hose running from the MAP sensor to the inlet manifold. The ends go brittle & split, resulting in a lower vacuum signal to the MAP sensor, causing it to run rich. This can show up even worse after doing the head gasket repairs, because you've disturbed the hose.
Cheers, from Mal.

Speedway · 11-14-2005, 15:46

Thanks guys

It turned out to be the Map sensor hose. The damn thing was off altogether! The hose has slipped down under the wiring loom so I couldn't see the open end. Plugged it back onto the sensor and the engine settled down immediately!

Cheers
Bruce

jas24zzk · 11-15-2005, 03:55

Good to hear!
i was actually going to ask if it was MPI or CPI.
Other things for future that will generate a similar response..
Dead Coil lead
Leaky injector (ESPECIALLY on CPI)

Cheers
Jas