I just finished installing a new in-tank fuel pump, a new pressure regulator on the carb., a new filter on the frame, checked the filters on the fuel injectors and they were clean as a whistle. These carbs. have no adjustments anywhere. If you turn the key, it will start up every time, but you have to keep reving it up to keep it running. As soon as you take your foot off, it shuts down. Will not idle. Is there anyone out there know anything about these carbs., or is there something else causing this problem. It has electronic ignition (DuraSpark EEC-IV) Could this be bad. Well, this isn't a truck, its a '84 mercury Grand Marquis. I figured in '84 they used this same engine in trucks, but not sure. Is there anybody out there that can help me out with this? I'm stumped. It's my wife's car and she really misses driving it, I don't know why because she's been getting to drive my '78 Bronco. Any help would GREATLY be appreciated. Thanks, Rob

 

Rob, have you used a fuel pressure guage? You need to find out what the fuel pressure is by calling a dealer or a Haynes or Chilton manual. You mentioned that you installed a new fuel pump,and if it isnt the proper pressure ie.. too low it wont idle or it'll die when you hit the throttle. I have installed alot of pumps and seen it happen more than once. Good luck. Windsor660

 

Hey windsor, i checked the pressure and it was 39 P.S.I. and thats what the chilton book says. It will start every time i turn the key, but want idle, every time it dies i here the pump continue running for a second, then it quits, turn the key fires right up, then dies. I've changed fuel injectors, coil and relays. Do you think it could be the brain box? The parts I replaced were used. Thanks for your help. Rob

 

Rob Dont take this personal,but it sounds like your spending alot of time and money changing parts you dont need. Have you checked (TPS)throttle position sensor?? (IAC)idle air control valve?? Do you have the tools to check stuff?? Talk atcha' later Windsor

 

Hey windsor thanks for replying, well, i have'nt checked the TPS, or the other thing you mentioned, and i also have no way of testing anything, just trial and error and this site. If i hold my foot on the gas, say approx. 3000 RPM's or something like that, the engine will not stay at that RPM. it will go up and down, like the fuel pump is loosing pressure and then regaining pressure. Is this possible? Why could'nt ford just keep it simple, like my '78 bronco? The reason for changing these parts and thinking it might be the brain box is when i hit a bump, the car would stumble, like a loose wire or something, im trying to actually fix two problems at the same time. I really appreciate your input. Thanks, Rob

 

Rob,what I would do is hook the fuel pressure tester again and watch while increasing r.p.m.'s and the chilton manual should give you psi at high and low r.p.m.'s and if its within' spec's that will eliminate the fuel problem.Next check your timing etc..to eliminate it.A bad EGR valve will make a engine run bad also.I know you dont want to hear this but if you dont have anything to work with to test parts, you probably should take it to a shop.I would say the ECM would be expensive and I would check everything else before I would condemn it to be your problem.You could also start car up and wiggle all the wires by ecm etc..to see if it changes anything. Where are you from??Its hard to fix a engine problem without actually hearing it run and being there. well see'ya later Windsor

 

Hey windsor, what i'll do is go to a u-pull-a-part junk yard and grab a brain box ( like all other parts ) and try that and see what happens. If thats not the problem, i guess i'll have to take it to a shop. My father-in-law has a pretty good mech. so he says, it's just hard for a working man, like myself, to go to a shop and not know 'em. I've heard to many story's of people getting ripped off. Well anyway, i live in Jax. Florida. How about you, where are you from? Right now it's about 98 degrees here, heat index about 105, man i cant wait for winter. Well windsor, i sure appreciate all your help, if you just happen to get a brain storm of an idea, i sure would like to hear it. Have a good day. Rob

 

 

Hey, Rob whats goin' on?? did you have any luck with your wifes car???I am in spfld Ill. and its just as hot here as it is down there.Bet you have alot more scenery(thong bikinis)down there!!!I'll be down in Sarasota in two weeks so I'll check it out then. Later Windsor (Rick)

 

Hey windsor, well what i thought was the carb. in the beginning, then fuel pump, then what ever else, turned out to be just the M.A.P. sensor. I unplugged the electric connection, tried to start it and would'nt start. Hooked it back up, and it fired up. Unhooked the vacuum line from the M.A.P sensor and it started idling, rough, but idling. Put my finger over the vacuum line and it smoothed out, for a second. Hooked it back up and it idled perfect,for a second, then died. I'm replacing the sensor this morning so hopefully i'll be through with this thing. Are you the same windsor that wants to put a 351w in your truck? well, have a good trip to Florida and yes, enjoy the senery, try to visit the coast, its very nice. Thanks again for the help, have a gooden. Rob

 

Yes that is me.I put 32-11.50-15 BFG A/T on it and it has 3.31 gears in it.I cant decide what I want to do,Im thinkin' that either way its going to cost about the same since Im doing all the work.Its a 95 ext.cab 4x4 Black w/302& a AODE.Ive thought about a supercharger,but their about 3000+ and I also want reliability.Im going to have it paid off in a few months so I hope I can decide by then. Talk atcha'later,Windsor

 

Hey Rick, well im not to good with all this high tech stuff '80s and up, but '79 and down is a piece of cake, as long as im standing in front of it. When you make up your mind keep posting i'll try and help as much as possible, and i'm sure there's alot of others that will too. Good luck on your project. Rob