1996 VP 5.0fi ford surges at idle, missing timing marks?

[Justin Kennedy]

Re: 1996 VP 5.0fi ford surges at idle, missing timing marks?

Still no luck. You name it, I've cleaned it or replaced it. I even installed the kit from Ford that allows you to adjust the air manually around the IAC. No luck. The surging seems to start after about 125 degrees. The engine is not hot, but it definately starts after its warmed up. I also noticed that if you throttle up to about 2000rpm, it slowly occilates about 100rpm up and down. Im going to try to find a knowledgeable marine mechanic that can put it on a diagnostic computer. Anyone have any recommendations in the Daytona Beach, FL area?

 

[Justin Kennedy]

Re: 1996 VP 5.0fi ford surges at idle, missing timing marks?

As far as vacuum leak, the only vacuum hoses are the one to the regulator and one to the vapor separator, I've visually inspected both, they seem fine, they fit tight etc..What am I missing? Maybe an intake gasket leak? I'll look into that but I know I cleaned that area real good before I put in a brand new gasket. One more thing, I have read over and over about disconnecting the battery to erase the Keep Alive Memory after replacing various sensors. It just dawned on me that I have been turning the Battery switch to off to do so. However, the EEC has its own power wire connected directly to the battery therefore when I turn the
Batt switch to off, the EEC is still powered. I am going to disconnect that wire tomorrow morning and see if it helps.

 

[Justin Kennedy]

Re: 1996 VP 5.0fi ford surges at idle, missing timing marks?

Still surging. I'm thinking dynamite might fix it.

 

[shdw2001h]

Re: 1996 VP 5.0fi ford surges at idle, missing timing marks?

did some searching on the internet and found it could be coil, or a sensor going bad. also check
for loose wire on the alternator. they can all be checked with a meter. but I do not have the info for how to do this.

 

[Justin Kennedy]

Re: 1996 VP 5.0fi ford surges at idle, missing timing marks?

I finally got it! Removed the upper intake manifold to do some double checking. While I had it off, I retorqed lower intake manifold bolts, they were suprisingly loose. I also re-cleaned all gasket surfaces and installed new gaskets. Again. Started it up and it ran perfect all the way up to 150 degrees. No surging at all. Im gonna water test tomorrow. Previously I tried spraying carb cleaner around intake while it was running to find leak. This tecnique failed me I assume because the access to the lower manifold and other potential leaks areas is limited because of the big upper intake manifold. Thanks for the help. Happy boating!

 

[Justin Kennedy]

Re: 1996 VP 5.0fi ford surges at idle, missing timing marks?

By the way, I found a great website for Ford EFI info. www.fordfuelinjection.org. Very informative!

 

[shdw2001h]

Re: 1996 VP 5.0fi ford surges at idle, missing timing marks?

glad to hear you found it.