Hi

It seems ever since i put my few mods on my car, when i run my car ill come to a stop and the rpms drop almost to the point that its gonna stall on me. Once and a while it will stall, others it will be what feels like a surge of air at the last around 1200 rpm.

On cold starts driving around in 1st and 2nd seem to hesitate a little and i can sometimes hear a whirring sound like air is leaking somewhere.. Boost leak says otherwise, no leaks are found . I recently added a Buschur 65mm TB and it seemed to help a lot. (My old one had worn out rings on the inside.)

When i press the clutch in at a stop it seems to help and it won't dip in RPM or try to stall, but i have only 30k miles on the car and i dont run my car hard so im kinda

This is the kind of problem I could spend thousands of dollars replacing crap and get no where, so I wanted to check the community first. I found someone with a similair issue with an NA lancer but no resolution.

Has anyone else had a similar problem that they could offer me some tips on? i dont want to waste my time taking it to the dealer because theyll just tell me that the car has mods on it so they can't touch it.

This is on an 03 evo.



Any help or comments are much appreciated, I'll check back from work tmrw.

Thx.

Lots of people have vacuum problems like this. What mods did you add recently? It's most likely those mods caused the problem, so I assume you switched those back to stock to test, right?

Yeah, I no longer own the stock airbox & cams etc though, so switching back to stock anything is not really an option.

I believe it started after messing with the airbox / intake, but it's been so long that I forgot - I barely drive it and lately it's just been bothering me so I wanted to see if anyone has had the same issue.

I have a new intake on the way - I guess I'll wait and see how it turns out.

I have an older AEM currently.

update:

I ran another boost leak test and found a leak in a weird spot. When I pressurize the system I hear leaks in around my valve cover.. I took the Oil Cap off the valve cover and sure enough there is air somehow getting in there.

Is this normal or? Anyone else seen or heard of this? I saw a few threads on it with no answers.. I really hope its not the rings.

I closed the garage for the evening, but maybe what I heard was PCV blowby


Do I need to cap the PCV line in order to run a true boost leak test?

are you tuned for the intake????? if not its your problem

Well I had a dynoflash about 2 years ago, I don't remember if Al customized it for that or not.

If you didnt have the intake at that time, then Im assuming you're not tuned for it...

not being tuned for an option like an intake will not cause a leak in the valve cover. i actually just saw a post like this last week, same problem. there were all kinds of bs comments like the piston rings could be bad. you need to search and keep posting till you can find someone who HAD THIS problem and solved because you never know the level of education your receiving from some of these guys here. i'm a mechanic myself for Caterpillar machinery but we don't have problems like these they just arent near the same so my evo is a learning process too. good luck

Not being tuned for an intake will not cause a leak at the valve cover correct but IT WILL cause the stumbling and such that he is describing... Since the problems seems to have started since the intake mod... Makes sense to me that it could be causing his stumbling. NOT his leak

what blow off valve are u running???

I had an intake at the time of the dynoflash..

+1. Sounds like everyday VTA problems to me.

i have an intake and im not tuned, my idle is fine

true and good point.

if you care to ask me i think your boost leaking into the valve cover is causing your stumbling. its all one problems and i have an idea where to look but like i said i'm learning on the evo's and i dont want to get bashed haha