1990 5.0 fuel problem???
#1
1990 5.0 fuel problem???
i have a 1990 f150 with a5.0, runs fine for about 20 minutes, then starts to miss. everything is new, plugs, plugs wires, cap is in good shape.i already ran 2 cans of sea foam within a couple weeks.i dunno if it could be injectors they have never been replaced the only way id know is to hook it up to a pressure test right?? forgot to mention..pedal to the floor it goes but if you tryin n slowly accel.it cuts up
#2
#3
well i actually elliminated the rear tank its just the side tank.my truck has been running good for a while and it just started doin it on a cold day. my buddy was sayin take the distributor cap off and look to see if there is moisture, it was fine.i dont think i have an ignition problem deff fuel problem did the same thing today once it warms up it starts running ****ty.im almost positive its injectors i just wanna be a little more sure.need sum more input...
#4
#5
Join Date: Nov 2006
Location: Memphis, TN 38135, USA, Earth
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No, the injectors are among the least-likely causes. Get a Haynes manual & test the TPS & MAP. If you can zip into a U-Pull-It JY and snag a spare MAP or 3, that might be quicker. You can get one from any '87-93 Bronco or gas F-series, and some later trucks.
I doubt it's fuel-related, and a '90 doesn't have the valve that an '89 does. A bad coil can do this, though, and Haynes has an excellent diagnostic procedure for the ignition system.
How exactly did you delete the rear tank? What did you do with the fuel lines?
I doubt it's fuel-related, and a '90 doesn't have the valve that an '89 does. A bad coil can do this, though, and Haynes has an excellent diagnostic procedure for the ignition system.
How exactly did you delete the rear tank? What did you do with the fuel lines?
#6
More than likely a bad MAP but don't rule out the TFI on it. Both will give you the same symptom. The MAP is the easiest to replace.
TFI= Thin Film Ignition- it's the little black box on the distributor. When they get warm they start to break down and yields a miss. It will get worse over time if it's the TFI and probably leave you some where.
TFI= Thin Film Ignition- it's the little black box on the distributor. When they get warm they start to break down and yields a miss. It will get worse over time if it's the TFI and probably leave you some where.
#7
when i eliminated the rear tank i just connected the lines from the side tank directly to the lines that run aling the frame..i dont think there is a selector on the frame i just replaced that little sensor on the side of the distributor not too long ago maybe 5 6 months ago what is the MAP and TFI.sensors would cause it to break up after 15 minutes??i dont really understand its pretty difficult trial and error ive been buying parts like crazy i just put a new coil in it..mad it a little better.but you say its most likely not a fuel problem?
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#8
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Actually, it's Thick-Film Integrated-IV (4th generation) Ignition Control Module.
Automotive Terms & Abbreviations
Automotive Terms & Abbreviations
#11
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#12
there is only 2 lines running down the side of the frame then it splits into a y and there was a set of lines running to the rear tank..those i took off and deleted the Y connector. The fuel pressure im pretty sure is the same or my truck wouldnt have ran right??..my truck has been running for almost a year like this
#15
my truck is still doing the same *******ING thing. new coil, new ICM, plugs. ignition is pretty much brand new i dont have resources to hook it up on a computer not alot of people cqn hook up a 1990..my light came on for about a minute then went off its really bothering me!!breaks up at 2-3000 RPM but it doesnt do it every single time o come to a stop it happens eevery so often SOMEBODY HEEELP!