Last night while driving around my car backfired HUGE (Loudest Ive ever heard, easily louder then a shotgun)
Now my car backfires anytime I am driving @ 3400rpm or higher and give it was gas and then let it decel under gear load.

Anyways, after it backfired, It wouldnt go above wastegate spring pressure. All AFR remain @ 10.9-11.2 under WOT. But It wont go above 8-9psi. I should be making 18psi.

Did the backfire damage the wastegate? is that even possible? No codes were thrown.
Dont Hear an exhaust leak really. All vacuum lines are intact.

So basically what mechanical causes for Haltech going to Wastegate pressure instead of target boost.


Haltech PnP Standalone.
ID1000 Inj
3" Single Exhaust
Momentum ST kit
TiAL MV-R Wastegate

 

only way its gonna stay at gate pressure is if the line coming off the wastegate top port has a hole.

there could be alot of other things wrong,. but if its still boosting to gate pressure at the same rpm, check the lines 1st

 

K nothing wrong with lines

Next check Boost selenoid?

 

ya if the boost solenoid isnt pulsing then you;d be stuck as get pressure as well.

you vacuum at idle didnt change did it?

 

I dont think so it might of changed by 2"Hg

 

How can I check it from pulsing?

 

just apply 12V to the solenoid to make sure its clicking.

you can do that by telling the haltech to run duty cycle at idle.

 

Would a bad Vband clamp in the uppipe be a cause? I hear a ever so slight whistle at idle. I cant seem to pinpoint it. But I remember my buddy saying my vband was closed all the way but it was still a very little bit loose.

 

I just went out and did some WOT pulls, and logged it.. did you want to take a look at the csv Str8? how do i post it?

Also I noticed that I make 7-8psi in 3rd, 6-7psi in 4th, and 3-4psi in 5th gear. It also seems really laggy. The Wastegate spring is I think 8.5-9psi.

 

Sigh.

Kinetix Velocity..... ****.

 

SO you found the problem OP? Leaky Kinetix? Time to upgrade to a Cosworth plenum...

 

Yes a 10 in crack along top of Kinetix, Im gonna weld er up, and sell it and get a cosworth haha

 

with the crack behind your TB, you should have seen a decrease in vac at idle. did you see that on your logs?

10" crack is pretty extreme

 

Maybe vacuum sucks it shut? LOL I bet that made a loud boom when it popped

 

Ya there was a little bit of a Vac drop, by only 1hg We thought it was a vac line, then pre turbo V band Clams.. etc etc. Good news, we took ALL piping apart and new vbands lol
Welded up the intake. Threw a 3.3 diff in and Its a wee bit faster then it was before. I think I had a small leak when it was tuned, because my AFR's used to be 10.9-11.1 now their 11.2-11.3 WOT.


.................................... I WAS UNDER DECELERATION WHEN IT BLEW haha.

 

Gonna give it a good polish tonight,