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1988 All Other Makes All Other Models Repair Question


Topics covered: Egr valve, Fuel filter, Rough idle.
Mileage: No information provided.

Asked on March 15, 2007

88 merc grand marque egr valve

88 merc grand marque, 5.0 L, FI, Air, 160K.
Problem: rough idle, stalling, choppy during normal driving, hard to start.

EGR valve has been replaced, same problem. However, when the vacuum line to the EGR valve is disconnected the problem goes away. I am not really sure what the EGR valve does or how it works. Could there be some kind of blockage in the air plenum that it attaches to. Any ideas on where to go from here would be appreciated. It has new plugs, wires, rotor, coil, and fuel filter. Thanks in advance for any help.

Robert
Avatar Asked by mrfixit435

Answer

Replied on March 22, 2007

The problem might be a 25.00 dollar part called the egr solinoid. It's small and has two wires and two small vacuum lines lpugged in to it. When you pull the vac hose off the egr is there vacuum at idle? There should not be!

Tiny Answered by merlin2021 (expert)
18,112 answers provided
Replied on March 24, 2007

Thank you for your reply...
Yes, there is vacuum to the EGR valve at idle, according to vac guage there is about 2 lbs.
Is the solenoid controlling the vac at the EGR valve? I take it if this is working properly there should not be any vacuum at the EGR valve at idle.
Thanks again for your help with my problem.
Robert

Tiny Response from mrfixit435
1 question asked
Replied on March 24, 2007

Replace the egr solinoid...Done! Get the codes cleared afterwards or the light will stay on for a while!

Tiny Answered by merlin2021 (expert)
18,112 answers provided