High idle on a 1998 Explorer with a 5.0L AWD.

[simpsons254055]

Just replaced stock intake on my ex put a new from jegs cobra intake on it. replaced my gt40p intake. after doing a lot of modifications to the EGR and AC also extending the vacuum lines to shorting the EGR tube and deleting the stock location on the cobra intake for the EGR valve and using my stock 90 degree throttle body with the EGR valve on there. I now have a high idle (1400 rpm) First starts it is at 2200 rpms and slowly drops to 1400 rpm and thats were it stays at until I shut it off and then it sounds like a turbo sucking and thats coming from the throttle body intake tube from the air filter. Is the stock mass air flow sensor not calculating the right amount of air and causing the high idle. Can't hear a vacuum leak. Any thoughts thanks in advance

 

[BrooklynBay]

I've moved your thread into the modified 95-01 section. Do you have a check engine light? Do you hear any noise similar to a leaking vacuum line?

 

[simpsons254055]

no check engine light yet just got it started today and noticed the high idle no vacuum leak sounds ethier

 

[techieman33]

I'm sorry to read you went through all that work for nothing. The explorer intake is basically a cast version of the cobra intake, I would be surprised if there was any power gain at all. You would have been much better off putting that money towards headers or an aftermarket tune. Or if you really wanted a better intake manifold spent a little more and bought a trickflow, or holly piece that would actually flow better. Or put about $200 into a port and polish job on your stock intake and been better off.

 

[simpsons254055]

I Agree with u

See the only reason I did this mod is because the stock lower intake cost more then this cobra intake. The stock intakes thermostat housing had a broken bolt in it and I had it removed, but the person that removed had a lot of trouble doing so and ended up drilling all the threads out and filling it with aluminum and retaping the hole and in doing so the mating surface was not even and I couldn't get the t-stat houseing to seal again. Tried 5 different rtv's and none of them worked. So this is why I went to the Cobra intake replica from jegs. Still need to know what could be causing me high idle. If u have any suggestions they would be appreciated thank you in advance!

 

[simpsons254055]

figured it out finaly after removing the intake again I found that I had the wrong intake gasket on it that jegs sent me so I had to get the right one everything is working fine so far thank u for your help!!

 

[CDW6212R]

Very good, glad you discovered the issue.

BTW, what was the problem with the gasket, did it not match and created a vacuum leak? I ask because another member here has a high idle after a lot of work on a 351W swap. Regards,

 

[simpsons254055]

wrong gasket

the intake ports were to big causing the bottom of the intake to not be sealede and caused internal crankcase vacuum. The pcv and the hose from the oil fill neck was sucking so hard. Jegs gave me the high performance gasket with bigger port holes instead of the stock gasket that goes on the truck.

 

[BrooklynBay]

Thanks for the update!