Contour Enthusiasts Group Archives Forums Modifications Duratec Performance New header install

If you have stored your car for awhile and then run it hard, chances are you may have damanaged your plugs electrodes. Pull the plugs and ensure the gap is within spec. My Explorer had a terrible miss at a certain RPM and it turned out that a gap adjustment of only .005 inches (from .055" to .050") fixed the problem. If it's a miss, it can only be 1 of 3 things, or a combination of the three. Fuel, Air or Spark. IACV could be the culprit, but I doubt it. Besides, checking/adjusting spark plug gap is free, and a new IACV isn't. Before making any changes though, run your gas down to nothing and then fill up with good quality gas. If the plugs are gapped properly, I would turn to the next cheapest item in line .. a fuel filter. If it's a stumble more than a miss, it could be the fuel pump. I would only fork over the dough for a new IACV if it was a last resort.

Yes the car has been sitting for awhile. I know the gas is probably down on octane big time I have to get a fresh tank of gas in it first. I'll check the plugs to make sure they are OK. The car runs fine but once it hits 5-6K thats when it just looses power/falls on its face. I'll try to get it out again this weekend, if it ever stops raining

Well here is the official staus on the car.
1 It's got a few exhaust leaks, main cat for sure and maybe a few more.
2 Spark plug OK.. I only checked one quickly
3 I filled it up with 93 so now I have a full tank of good gas.
4 The car will not rev out at all. Once it hits 5,500 it falls off immmediately. After that it takes forever for it to rev past 6K. I held it flat footed in 2nd, 3rd, and 4th and it just won't rev past 6200. It take s very long time for the revs to climb past 5500 to 6200. I'm getting to think I either have a major problem or something very stupid wrong with the car. I want to fix some of the exhaust leaks first so I can make sure the manifold gaskets aren't leaking( I have a very strange feeling the front one might be)I also have a little exhaust system tweaking to do. The car pulls very good from about 2500 to 5500, and really comes on around 4500-5K, but then just falls on its face at 5500????? I'm really baffled by that I guess I'm just gonna have to triple check eveything I touched while installing the headers. Oh and I still haven't got a single CEL yet!!!!!!Thats what is really driving me nutz Of all things to

falling flat at high rpms also sounds like the IMRC isn't working, but your symptoms don't describe a failing IMRC to a "T." There's an easy check for it, though - rev the car by hand and see if the linkages are moving. (They're visable, just below the TB)

I;m just about to check that out.

ImRC is ok and operational...the mooose is back though I year old IAC and shes a moosin The car falls off at 6K for sure now.

fuel pump is ont he way out!

I don't think so... The IMRC is all screwed up. return spring is broke inside the IMRC. The linkage from the rear bank to front bank wasn't connected, the grommets are missing. After I get all the sorted out I'll see how it runs.

Well my car wouldn't rev past 6K at all. I found the secondaries linkage not connected on the front bank. So, I tore apart the UIM/LIM and cleaned everything while I was at it. The manifolds where nasty. I got it all back togeter last night with new gaskets and secondary linkage grommets. The car is a whole new machine it friggin pulls hard as hell at 4K and up. It sounds mean as hell once the secondaries open.