More Crossfire Injection Help Needed
Thread Starter
Instructor
Joined: Feb 2012
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More Crossfire Injection Help Needed
Long story short, my car started all of a sudden running rough. I replaced my fuel filter and replaced the old banged up metal lines with new ones. I'm now getting 10-13psi from 700-4k rpm's. The car was 'chugging' at all but hard acceleration. This may sound weird, but it also sounded loud and was running lean (spark plug were tanish). I unplugged the IACV's and tighten a ground by the front of the manifold (not really loose before, just somewhat). And now the car runs like a sewing machine. The weirdest part is that the computer is throwing NO codes even with the unplugged IACV's. Any ideas?
Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
Not sure what your question is. Sounds like it WAS running poorly, but you replaced the filter, fuel lines, unplugged the IAC's and tightened a ground? And now it's running like a sewing machine?? I'd say you're doing alright.
Disconnecting the IAC's won't throw any engine codes. There is no "feed back" in the IAC system so the ECM doesn't "know" if they are connected, disconnected, working or not. They send signals to the IAC's and that is IT. No feed back, no codes.
BTW, "tan" plugs is not lean. on today's EFI vehicles, even "white" is pretty normal.
Disconnecting the IAC's won't throw any engine codes. There is no "feed back" in the IAC system so the ECM doesn't "know" if they are connected, disconnected, working or not. They send signals to the IAC's and that is IT. No feed back, no codes.
BTW, "tan" plugs is not lean. on today's EFI vehicles, even "white" is pretty normal.
Thread Starter
Instructor
Joined: Feb 2012
Posts: 105
Likes: 0
My bad, I was in kind of a rush to post it. I replaced all the fuel lines, etc and that affected the poor performance at a minimal to no effect level. So the engine doesn't know if the iacv's are there? What would the effect of unplugging them have? Just make the engine run richer because it's trying to adjust for the rpm's?
And thanks for the quick response by the way.
And thanks for the quick response by the way.
Not sure what your question is. Sounds like it WAS running poorly, but you replaced the filter, fuel lines, unplugged the IAC's and tightened a ground? And now it's running like a sewing machine?? I'd say you're doing alright.
Disconnecting the IAC's won't throw any engine codes. There is no "feed back" in the IAC system so the ECM doesn't "know" if they are connected, disconnected, working or not. They send signals to the IAC's and that is IT. No feed back, no codes.
Disconnecting the IAC's won't throw any engine codes. There is no "feed back" in the IAC system so the ECM doesn't "know" if they are connected, disconnected, working or not. They send signals to the IAC's and that is IT. No feed back, no codes.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
In MY CFI car, unplugged IAC's caused a low idle when COLD (below ~20F, cold start), but otherwise, it was not noticeable when the were unplugged.
The IAC's have no effect on the air/fule mixture. That is controlled by the ECM, using signals from the MAP, coolant sender, TPS and RPM...mostly. All the IAC's do is let more air in, or not to control idle speed -like a mini throttle. The ECM REACTS to the changing air flow by seeing changes in MAP and RPM and adjusting the fuel mix accordingly.
