Melted IAC

[Pookapotamus]

So anyone that knows my jeep knows that my hood is pretty religious,
That being said, I have been having idle issues lately, and stumbling under light acceleration (the odd time I don't have the pedal to the floor to hear the exhaust whistle) so in have been thinking IAC and tonight I decided to have a look at it.
First thing I noticed was I could not even touch my fuel rail after mort sat for 15 mins with all three fans on to cool him down. Pulled the IAC and it was clean but a light tug on it and it came right apart.

So... Apparently my under hood temps are still pretty high, I have a stainless borla header, with the late model intake (also way too hot to touch) gauges say I'm running around 100f.

I don't want to wrap the header because I have heard that doing a water crossing the wrap can hold water and crack the header. Is this true or not?

Is it possible to wrap the fuel rail? Would this be a problem in winter?

Is there some spray on insulation you could get for the intake?

Is a custom heat shield in my future?

Any advice???

[4.3LXJ]

Custom heat shield might be the ticket. They do make one for that intake to insulate the fuel rail and get rid of the #3 miss the late models have. I made a heat shield for my exhaust out of a double layered cookie sheet. Works great and easy to work with

[Pookapotamus]

What about the wrap Steve? Have you used it?

[4.3LXJ]

Yes I have. It accelerates corrosion when wet, so I took it off

[Pookapotamus]

Even with a stainless header?

[4.3LXJ]

Not sure on that. But stainless does corrode too with heat and exhaust gasses. I really think one of the most effective wraps would be with multiple layers of aluminum foil and a couple of hose clamps to keep it in place.

[gary63]

you might try eastwood's 2k ceramic underhood high temp.paint or there Hi-Temp internal exhaust coating w/extension tube.

[Pookapotamus]

Thanks Gary I'll look into that!

[Carves]

Rusted out an expensive, replacement set of headers on an old 1000cc suzuki years ago ... thanks to the myth that header wrap is good idea.

Didnt take long either.



Just as a thought, and as a test

... slap some magnetic vehicle decal material over your front vents ... in case they are reducing flow past the manifold.

Shouldnt be an issue really tho - as the front vents will usually draw air from most spots in the engine bay.

[Pookapotamus]

I borrowed a laser thermometer from work, now I can at least see what temps I'm running. Go from there. Awesome advice carves! Still stalled 5 times this morning, did not seem to stumble too much though.

[Pookapotamus]

So the new IAC did nothing!!!

Fuel rail temp when I got home was average, 95*c intake temp avg was around 110*c, header temp at head was 120*c and at the collector 270*c.

Methinks that with all the venting I have in the hood it's pulling all that heat up around the intake and rail, where as a stock hood will allow the heat to be pulled down and out. At least at any sort of speed.

So...I'm thinking of wrapping the intake and cutting the fins between the ports to allow as much heat as possible to escape, and wrapping the fuel rail. And maybe add a heat shield between the block and header.

Opinions?

[gary63]

what I have done to help the heat soke is wrap half of the fuel rail the bottom and lift the top open so air can get around and heat can go around the rail and not heat it up. now I'm working on trying to wrap the bottom half of the intake to see if it can make it any cooler.

[Pookapotamus]

Number 6

Number 4

[4.3LXJ]

Looks like that might be running a wee bit warm. You burning oil Dana?

[Pookapotamus]

Yes, 4,5 and 6 ports have oil in them.