Archived 97 12 vavle loping at idle

[moparmafia1998]

Having issues with my 97 12 valve. I have checked the fuel pressure and it is good, check all hoses all a fairly new. This only happens at idle otherwise runs like it should. It will idle and then just start loping like it has a big cam. i can tap the throttle and it will stop but i can also tap the throttle to make it start loping. Idle is set at 850. I can also crack the injector lines and will stop to. Please help. Have had diesels for awhile but just joined the site and i love it!

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[Sticks]

Any injector line in particular or any of them?

 

[moparmafia1998]

ive tried all of them and its not a consistant one. Sometimes one will and the next time it wont. talked to piers diesel and they said i could still have a suction leak somewhere or a sticking plunger in pump? Its been over 100 the last few days so i havent messed with it. Supposed to cool down this weekend

 

[Sticks]

I concur with Piers. 12v engine fuel supply components have issues, particularly the fuel heater (starts sucking air in through the port where the wires go in). Best and only way to check that, that I have found, is to pressurize the fuel tank to 10psi and look for leaks.

Other than that, the pump is probably the culprit.

 

[moparmafia1998]

Was thinkin the pump was the prob but was tryn the cheap fixes first. If its the pump... time to up grade to a 215 pump!!! Thanks for the input!

 

[Sticks]

Verify your fuel supply first. Hate to see someone drop big $$$$ on a new MFIP and find out it was a supply issue.