Losing Power

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Cerulean

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Whenever I push the gas pedal on my 1990 Bronco with the 5.0 302 down more than an inch or so the truck seems to lose power. It sputters and backfires and just doesn't want to go. The only way I can get it to pick up any speed is when I pump the pedal repeatedly while only barely pressing it. Everyone kept telling me I needed a new distributor cap, rotor, plugs or wires. I changed all of those and there's no change with the problem. It just keeps sputtering whenever I drive it. I could press the pedal all the way to the floor and all I get is sputtering, a few pops, a backfire or two and no power.

I know the first thing people always say is to read the codes, but I don't have access to a code reader at the moment, nor the money to buy one. I've also replaced the fuel filter with no change. So far friends have mentioned everything from leak in a vacuum hose to needing a new fuel pump. I was just hoping to get the opinions of people who actually own similar vehicles and may have experienced something similar.

If anyone has any thoughts, please let me know. In the meantime, I'll be trying to get my hands on a code reader. Any ideas on what could be wrong would be greatly appreciate though.

Thank you,

C.

 

92bronco_in_progress

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Whenever I push the gas pedal on my 1990 Bronco with the 5.0 302 down more than an inch or so the truck seems to lose power. It sputters and backfires and just doesn't want to go. The only way I can get it to pick up any speed is when I pump the pedal repeatedly while only barely pressing it. Everyone kept telling me I needed a new distributor cap, rotor, plugs or wires. I changed all of those and there's no change with the problem. It just keeps sputtering whenever I drive it. I could press the pedal all the way to the floor and all I get is sputtering, a few pops, a backfire or two and no power.
I know the first thing people always say is to read the codes, but I don't have access to a code reader at the moment, nor the money to buy one. I've also replaced the fuel filter with no change. So far friends have mentioned everything from leak in a vacuum hose to needing a new fuel pump. I was just hoping to get the opinions of people who actually own similar vehicles and may have experienced something similar.

If anyone has any thoughts, please let me know. In the meantime, I'll be trying to get my hands on a code reader. Any ideas on what could be wrong would be greatly appreciate though.

Thank you,

C.

first and foremost, check for vacuum leaks, theres on a few vacuum lines so its fairly easy.....after that check your fuel preasure, keep in mind your truck has 2 fuel pumps, a low presure in the tank and a high preasure on the driver side frame rail

 

BroncoJoe19

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I have a '90 and I agree that you should check for vacuum leaks... that was by far my first thought. It was in 1990 that they changed to a single fuel pump in the tank. IF you have a feul pressure guage, checking the pressure at the rail is a good idea. Should be about 35 psi.

You can pull codes without a scanner, all you need is a 4 inch piece of wire and the ability to count to ten.

In the begining of this little tutorial there are tips for checking for vacuum leaks.

Here you go. Read this thread.

How to scan FORD on board Diagnostic Trouble Codes (DTCs) in your driveway

Howto Pull Codes 1983-1995 Broncos, Mustang, F series Trucks, Econolines, 302, 351 and more

Let us know which codes you get when you are done.

 
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Cerulean

Cerulean

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Well, I used the "paper clip method" to read some codes earlier and these are the two that I got. I'm not exactly mechanically inclined, to say the least, so any advice on checking on these further would be appreciated.

Code 33: EGR valve opening not detected.

Code 87: Fuel pump primary circuit failure. When the FP relay was activated by the EEC, voltage was not detected on the control circuit.

 

miesk5

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Cerulean

Cerulean

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I'm in the process of trying to check all of these things out. Truthfully, I've no idea what I'm doing bu I'm trying to learn as I go.

However, a new problem has developed. I tried to put new spark plug wires on again but there was no change so I went back to the old ones, which were still relatively new. During the process, I also removed the air filter to check it, and it was pretty bad. However, I tried to drive it around the block and.. oops.. forgot to put the air filter back in. I did so as soon as I realized it and I'm going to replace it today anyway.. but now whenever I get the truck up to about 15 mph or so the entore engine starts to shake like mad. Not vibrate, but shake. It shakes a bit even when just idling in park, but it's horrible when I'm driving. This is something new I've never had before, so I must have done something wrong. Any thoughts?

I really appreciate all the help. Thanks.

 

bigtrux

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Well first i would check to make you you put your wires back on right in the correct order make cap/rotor is tight. but you may have knocked a wire or vacum line off with these old trucks it's easy to jack the vacum line connections because most are brittle from age. and you probally have a bad fuel pump which one who knows. but thats why it gets power when you pump the pedal your building up the fuel pressure, good luck ...

 

BroncoJoe19

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1990 was the year that ford went to a single fuel pump in the tank in the full size bronco. You should have approx 35 psi at the fuel rail. IF you look closely on the driver's side on th etop of the engine there is a little tire valve looking thing. That is where you would check the fuel pressure with a fuel pressure guage.

 

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