89 f350 460 problems
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89 f350 460 problems
Hey guys, I have an 89 f350 with the 460 in it. Two days ago everything was fine, now it won’t go faster than 55mph with the pedal all the way to the floor.
I did a fuel pressure check and that was out of spec so I replaced filter and high pressure pump, now I’m in spec but no change. I did a compression test and got 165-180 on each cylinder, so that seems ok. New plugs, wires, and cap, no change. Exhaust removed to check for plugged cat/muffler, no change. Vacuum check will be tomorrow but was wondering if any of y’all have experienced this and if so, what was the culprit for you? I’m expecting tps/IAC/Map sensors are going to need to be replaced but wanted to try and “diagnose” before I throw random money at the truck.
Thanks I’m advance!
I did a fuel pressure check and that was out of spec so I replaced filter and high pressure pump, now I’m in spec but no change. I did a compression test and got 165-180 on each cylinder, so that seems ok. New plugs, wires, and cap, no change. Exhaust removed to check for plugged cat/muffler, no change. Vacuum check will be tomorrow but was wondering if any of y’all have experienced this and if so, what was the culprit for you? I’m expecting tps/IAC/Map sensors are going to need to be replaced but wanted to try and “diagnose” before I throw random money at the truck.
Thanks I’m advance!
Lead Driver
Joined: Jan 2019
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From: N.W. Alabama
keep the parts cannon locked up, and check for codes first, even if CEL light isnt on, could have stored codes.
Then test parts first before buying new, with the knock offs, you could get bad right out of box, and still have same issue.
Then test parts first before buying new, with the knock offs, you could get bad right out of box, and still have same issue.
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parts cannon is holstered....I forgot to mention that there are no codes koeo/koer or in memory. Parts stores here didn’t have a vacuum gauge today so I will just be using the ole multimeter to see if I can find anything.
Lead Driver
Joined: Jan 2019
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From: N.W. Alabama
Did you at least get, system good '11' code,
tps check-->Throttle Position Sensor Testing, Replacement and Adjustment - Ford Bronco Forum
iac check-->How to Clean and Test your IAC - Ford Bronco Forum
map check-->Fuel Injection Technical Library » Manifold Absolute Pressure Sensor (MAP)
tps check-->Throttle Position Sensor Testing, Replacement and Adjustment - Ford Bronco Forum
iac check-->How to Clean and Test your IAC - Ford Bronco Forum
map check-->Fuel Injection Technical Library » Manifold Absolute Pressure Sensor (MAP)
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I have 12” of vacuum at idle, coming off the manifold. Is that enough? I feel like that’s low but I can’t find what I’m supposed to have.
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Cargo Master
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That seems quite low to me, but I have no idea what a stock EFI 460 is supposed to pull at idle. I would *guess* based on experience, closer to 20"
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More info...vacuum was actually fine, 20” at manifold. So, it only runs this way when the engine is warm. The first few minutes it runs like a new truck, then it starts acting up. Anybody got any late ideas before I have to take this thing to a shop?
Lead Driver
Joined: Oct 2016
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From: Houston/Sugar Land
Did you at least get, system good '11' code,
tps check-->Throttle Position Sensor Testing, Replacement and Adjustment - Ford Bronco Forum
iac check-->How to Clean and Test your IAC - Ford Bronco Forum
map check-->Fuel Injection Technical Library » Manifold Absolute Pressure Sensor (MAP)
tps check-->Throttle Position Sensor Testing, Replacement and Adjustment - Ford Bronco Forum
iac check-->How to Clean and Test your IAC - Ford Bronco Forum
map check-->Fuel Injection Technical Library » Manifold Absolute Pressure Sensor (MAP)
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