IMRC rebuilt, new codes

[jdsupertinter]

98 Cobra vert

Ok, rebuilt IMRC’s, new bearings, new o-rings, used old gaskets cuz everyone says they’re good over and over again.
Runs wayyyy better. Got a kick at low and and at 5k, awesome. But....
Now throwing a 0171 and 0174 code, actually the 0174 was first.
Went in checked connections, retorqued, everything seems fine.
Those composite gaskets looked old, sure they were intact, still soft. But where it folds over in some places make me suspicious, it’s 21 years old!! Could that cause the code?
Also on opposite side of throttle body is a metal thing that bolts to intake, there was no gasket there, just some weird silver gaskety stuff, does that need a special gasket? Could it be leaking there?
Any suggestions are always appreciated!!
Thanks.

 

[Tillerman77]

Have you tested for vacuum leaks yet?

 

[ViciousBlack97]

The thing you're referring to is the EGR valve, and I've reused what gasket was left stuck to both surfaces before without issue. I'd just double and triple check everything again, especially the fuel injector o-rings, since they can get rolled over on install and cause a vacuum leak.

 

[jdsupertinter]

I just remembered, one of the injector collars, on the bottom of the injector, had a small chunk missing, oring still went on snug though, but I thought it looked fugly.
So I’m gonna fix the obvious first, thanks for reminding me!!
Question, since I got a hella kick at low and high rpm’s now, I can assume the IMRC plates are good, right? I’m just concerned about the aftermarket orings I put in there, seemed to go in fine. But if they were bad I would get issues during acceleration I would think.


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[Tillerman77]

It does sound like your IMRCs are working properly. The transition RPM is 3250.

 

[ViciousBlack97]

Best thing would be to either get a propane torch, attach a hose to it and use it to find the leaks by listening for engine RPM to increase, or a smoke test for any potential vacuum leaks

 

[jdsupertinter]

I’m gonna replace the broken collar injector and go from there, I’m thinking at high rpm it’s sucking a little air, hopefully that’s it.
Then start looking for leaks, thanks.


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