91 Grand Marquis start then stall

[HATNINJA]

ok i have fuel press but i think it only has pressure in the prime or the start up you know when it pumps for 2 secs when you turn on the key. i changed the relay and filter. still the same thing start then stalls. the next step is to find out if there is any thing else that controls the fuel pressure after start other than the relay? guys i need to fix this thing befoer it snows tomorrow this is a beast i pushed it when this happened there is no way ill be able to push it in the garage. oh and ill let you see my wifes boobies shes hottt!

[DarkKnight]

Do you know if youu have a switch in ure trunk? where if the car rolls over it will keep fuel from pumping? Might beelcated else where too. Im not familiar with the 91. but if yuu find it see if yu can press it down.

[HATNINJA]

i said it has pressure the inertia switch shuts off the pressure

[marquisman]

does it run if you hold the throttle an 8th of throttle while starting it?

[85crownHPP]

I think this is one weird thing that can happen when the ignition switch goes bad.
'Run' and 'start' are two different sets of wiring for at least the ignition. I may be wrong but I want to say the fuel pump too...
Either way, one trick you can try is something that got me out of a pickle once. You will need two people, but have someone stand at the starter solenoid and pop the 'start' signal wire off once it starts up. Keep holding the key in the 'start' position, and it may keep running.

[gadget73]

could also try hot wiring the fuel pump relay to force it to stay on. Whichever wire in the self-test connector that has 2 wires going to the same terminal is the one you want. Ground that wire and the pump should stay running the whole time the key is on.

Nothing else controls fuel pressure really, just the relay, pump, and inertia switch. There is a fuel pressure regulator, but unless its squirting fuel through the vacuum line, its probably OK.

[HATNINJA]

wow progress

does it run if you hold the throttle an 8th of throttle while starting it?

yes it does man this is wierd so what next i was about to take gadgets advise and just replace the tfi mod but i decided to try 1/8 throttle and it did run for about ten seconds then i moved the pedal then it stalled but it stalled slowley not sputtering stall but a slow blugh kinda stall. so what u think could this be tps like i said ford systems were back in a vault in the back of my brain locked up all rusty with cobwebs all over

[marquisman]

this is a long shot but, is it possible that the IAC is pluged badly?

[HATNINJA]

hmmm

this is a long shot but, is it possible that the IAC is pluged badly?

ill try that first i had the wife buy a tps on the way home but ill first try cleaning the iac i did notice the intake was pretty gummed up.

[HATNINJA]

I FU**IN HATE THIS SHIT!!!

Ok the snow has melted so i went out and started throwing parts at it and still the same thing start then stall. I changed the tfi module, tps, map sensor, took off the iac and cleaned it checked for voltage yes there is voltage, fuel filt, and yes the pump is working. I checked for codes KOEO and got 21,24,34. I cant do a KOER because the thing wont run. Now i know that general moters had a test they ran before codes to check the computer does ford have one? Is that what the code 11 is supposed to be? In this shitty manual i bought it shows a code 11 and all it says next to it is pass. Well fuck me stupid the book dosnt say if this is the pcm check. Can the absense of this code 11 mean that my pcm is fried?

[91waggin]

Code 11 means everything is happy. If you get other codes, you won't get a code 11.

21--Engine Coolant Temperature (ECT) sensor out of range

24--Intake Air Temperature (IAT) or Vane Air Temperature (VAT) sensor out of range

34--EVP sensor is/was high

Check out your ECT first. Almost entirely by itself, this controls mixture during open loop (until operating temp or 10 mins of running have passed)

[gadget73]

was the engine warmed up? If not, that explains the 21 and 24. If it was fully warmed up, those sensors are your problem.

34 probably means theres a chunk of crap under the egr valve, or the position sensor is bad.

and 11 is the hunky-dory code. You get that only with no other codes.

Based on the fact it runs with a little throttle, but won't idle I'd say your IAC is shot and stuck fully closed. If that doesn't open, it won't start and won't idle. Pull it off and clean it, it may just come back to life. Or it may not.

[HATNINJA]

ok ill try cleaning the egr tomorrow the iac is clean and moves freely also has 12 volts at the connector with the key on. i knew what the codes were i read them in my book i just wanted to keep you all apprised of everything. is there any way to check the iac moter itself to see if its operating?

[HATNINJA]

car only ran about ten seconds at one position on the throttle, ran real shitty for ten seconds then stalled when i tryed to move the pedal.

[gadget73]

the iac is a bit hard to test. it doesnt really run on 12v exactly, it has a constant hot and a controlled ground to vary the position. I'm not sure how to duplicate that without a variable power supply of some sort. Its even possible that its not strictly voltage controlled, but it may have some sort of variable frequency pulse signal. The EGR works that way. basically i just swap them with a good used spare to see if it changes anything.

sounds like a massive vacuum leak, which a stuck open egr valve can cause. be sure to replace the egr valve gasket when you pull it off.