5.0L HO issues...still

[marquisman]

its been a while since i worked on the wagon since its summer and i drive the lincoln for summer but i thought id be smart and work on the wagon before winter so i have a reliable car for when winter does come. the problem is that all cylenders run rich. iv replaced sensors, injectors ECM an even replaced the wiring harness. the damn thing will burn your eyes out if its in a garage lol. what the heck would cause this shit?

[tim marks]

im not familiar with yor particualr setup but i would suggest possibly the fuel pressure regulator or maybe a stuck o2 if its been sitting a while. are there any codes?

[mrltd]

fuel filter?

[tim marks]

what size injectors are you using and what computer?

[marquisman]

02 sensor switching not detected, always running rich. thats what i get. all sensors have been replaced and nothin has changed. this was to be a simple HO conversion but, yea.....i also did a compression check on the engine just to make sure there aint a dead clylinder but, i get 140-150psi accross the board.

[marquisman]

the orange 19lb injectors and a '88 mark VII ECM. iv gone though differnt ECMs and injectors and sensors and wire harness' and so on even the fuel pressure regulator. only thing stock is the plenum and fuel rail. im gonna check the timming again and try to go from 10* to 11-12*. but like i said, ive gone through it all lol

[tim marks]

are you running cats on it?

[marquisman]

yup, they are new magnaflo high-flow cats

[mrltd]

MAP has been changed? How much of the harness has been changed?

[88grandmarq]

Either have uncontrolled/excess fuel pressure (fautly pressure regulator OR a clogged/kinked return hose.
get a fuel pressure guage and check the fuel pressure. with the vaccum hose off the regulator, fuel pressure should be 38-42 psi
with the engine idling and vaccum hose attached to the regulator, fuel pressure should be 30-32 psi.
Or there is Vaccum leak.

Is the MAP sensor connected to direct manifold vaccum?
Is the fuel pressure regulator connected to direct manifold vaccum?
Are the metal vaccum fittings on the upper intake installed correctly, tight and sealed?
Check the PCV system and hoses, make sure the PCV grommett is seated and the PCV valve fits snuggly.
might also want to look at the Brake booster and the cruise control servo, both can be a potential HUGE vaccum leak.
get a Vaccum gauge and a hand held vaccum pump, start testing stuff.
Don't over look the obvious and dont assume anything... check it !
After my HO conversion, I found the check valve on the vaccum hose going to the air pump was installed backwards. Vaccum was being sucked through the air pump vent.


Also.... make sure you have the correct throttle body and EGR gaskets installed.
installing stock CV size gaskets on HO size upper manifold will cause problems.

[1980c10]

Is your ignition system up to par might not be getting a full burn with a weak ignition. Also Is it so rich it's fouling plugs?

[tim marks]

wouldnt a vacuum leak cause a lean condition?

will it flood itself at idle?

im thinking its got to be something with the fuel pressure regulator

[marquisman]

my concern is fuel pressure and timing. the ignition sys is good, the coil is very powerful on this car lol

[88grandmarq]

wouldnt a vacuum leak cause a lean condition?

will it flood itself at idle?

im thinking its got to be something with the fuel pressure regulator

Yes... it would cause a lean condition.
thats why he is getting trouble codes... the 02 sensors are reporting a lean condition and ECM commands full rich to try to compensate.

[marquisman]

i cant get this thing to run with out adjusting the throttle to the point that the screws spring gets fairly compressed