Engine 1988 5.0 bucks and pops

Mike1988

Member
Aug 21, 2018
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Hey all. Been trying to self diagnose a problem with my 5.0 that just happened out of no where. Was driving around the other day and the car started to buck, jerk, have little power, won’t rev through rpms, and I will hear a popping noise fro the engine bay when I try to give it some gas to accelerate. Has brand new plugs, wires, distributor cap and rotor on it as well as a new fuel filter. TPS volts read at .56 on a closed butterfly, to 4.something when gas pedal is fully depressed. Any help or guidance would be great, thank you in advance.
 
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jrichker

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Dump codes sticky

Look at the top of the 5.0 Tech forum where the sticky threads are posted. One of them is how to dump the computer codes. Codes may be present even if the CEL (Check Engine Light) isn’t on. You don’t need a code reader or scanner – all you need is a paper clip, or if your lady friend has a hair pin, that will do the job.
I highly suggest that you read it and follow the instructions to dump the codes. http://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4.889006/
 

Mike1988

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Aug 21, 2018
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Haven’t checked for codes yet, but just check fuel pressure at the rail. Gauge said 15-20 pounds of pressure. Could a bad fuel pump cause this or would a bad fuel pump show no pressure at all? Maybe something in the line?
 

Mike1988

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Aug 21, 2018
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I believe it should be 35 psi and 39 with vacuum line unhooked and plugged.

Do you think the pump would run at a lower pressure if it was bad? Or just stop working completely? Don’t want to get a new pump if the problem for low fuel pressure is just something clogged in the line
 

Tugamypuda

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Jul 30, 2018
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Do you think the pump would run at a lower pressure if it was bad? Or just stop working completely? Don’t want to get a new pump if the problem for low fuel pressure is just something clogged in the line


A weak pump or not enough voltage to the pump will show lower pressure. It wont just stop unless it is completely bad. Make sure you got a good fuel filter. Unplug vacuum line and plug it with your thumb and check pressure. Should be 39 psi.
 

General karthief

wonder how much it would cost to ship you a pair
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It could be a bad fuel pump, it could be the rubber fuel line that connects to the pump. Make sure you have the fuel filter flow correct but I suspect you will be dropping the fuel tank.
 

Tugamypuda

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Jul 30, 2018
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And if u do drop the tank dont just slap another one in and put back together. Take the time to look at the harness. Verify that you do have 12v and a ground to the pump. Put some die electric grease and a new relay wouldn't hurt. This way you would have all that covered and not have to drop again in the future.
 
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Mike1988

Member
Aug 21, 2018
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Great. Will be dropping the tank tomorrow and I’ll let you all know how that goes. I’ll double check but almost certain flow of filter is correct as well