Car spits and pops on boost

[HOOCH256]

Well I took the car out for a spin and when I got on it it cut out really bad and the A/F just goes super rich. Noticed it was over boosting and I didn't hear the wastegate opening, so I checked and the vacuum line from the controller to WG was melted, I put a new hose on and tried again and now the wastegate opens but it still pops and cuts out and the A/F just reads rich. As soon as I start to roll into the throttle the A/F is at 10. The car drove just fine earlier today just parked it and got back in a few hours later and this was the problem. Any help will be greatly appreciated.

90 Eagle Talon Tsi
AWD
4g63
272 cams
FP mani
Hx35 bullseye housing
FIC 950s
Custom FMIC
Dijon intake
GM MAF with translator
Burned emprom ecu
Dual HKS BOV

Update 3/3/14

alright guys sorry it took so long to get this updated but i work out of town and my mech was super busy and just now got it in. Now when we had the leak down tester hooked up to cyl 4 you could hear a slight hiss of air coming out of the oil fill cap. but here are the results of the leak down and comp test...

comp test cold
cyl 4- 90#
cyl 3- 95#
cyl 2- 95#
cyl 1- 95#

Comp & leak down Hot
cyl 4- 93# & 18%
cyl 3- 110# & 4%
cyl 2- 110# & 4%
cyl 1- 110# & 4%

Fuel pressure 39#

 

[Kdouglas89]

Well I took the car out for a spin and when I got on it it cut out really bad and the A/F just goes super rich. Noticed it was over boosting and I didn't hear the wastegate opening, so I checked and the vacuum line from the controller to WG was melted, I put a new hose on and tried again and now the wastegate opens but it still pops and cuts out and the A/F just reads rich. As soon as I start to roll into the throttle the A/F is at 10. The car drove just fine earlier today just parked it and got back in a few hours later and this was the problem. Any help will be greatly appreciated.

90 Eagle Talon Tsi
AWD
4g63
272 cams
FP mani
Hx35 bullseye housing
FIC 950s
Custom FMIC
Dijon intake
GM MAF with translator
Burned emprom ecu
Dual HKS BOV

Are you running link? Can you post a log or anything? Do your plugs look ok? Did you pop off a major vacuum line that you are not seeing?

 

[HOOCH256]

I will be pulling plugs here in a bit, and no I'm not running link best thing I could do is try and record it. I'm just trying to think what major vacuum lines could have gotten knocked off? I might have to wait till tomorrow and look in the light

 

[Gerg]

Is it possible that the CAS may have gotten moved at all? That would of caused the ignition timing to be off, and your car will run horribly until it is set right.

 

[HOOCH256]

Here's a few other things I noticed while just driving home. At idle it shows 5# of vacuum. And at idle it's A/F is around 11.5-12 when before it was 14-15. Car runs fine until you hit around 18-19#, if I stay under that you don't even notice it. I normally run the car at 25#

Is it possible that the CAS may have gotten moved at all? That would of caused the ignition timing to be off, and your car will run horribly until it is set right.

I will check this out, but like I said in my other post is it runs fine till 18-19# then starts to cut out

 

[Kdouglas89]

I will check this out, but like I said in my other post is it runs fine till 18-19# then starts to cut out

I am 78% sure you have a boost leak somewhere. Please report back after you have done a proper boost leak test, and we can diagnose from there.

 

[codym]

I am 78% sure you have a boost leak somewhere. Please report back after you have done a proper boost leak test, and we can diagnose from there.

I like your calculations A boost leak could definently be the issue.

OP are you recirculating your BOV(s) or venting to atmosphere?

A boost leak post MAF and/or venting to atmosphere (without the proper setup) would cause less air entering the engine then what has already been read by the MAF, causing you to run rich.


However since you noticed a spike in your AFR at idle, I would lean more towards a boost leak.

 

[1G Eclipse94928]

I like your calculations A boost leak could definently be the issue.

OP are you recirculating your BOV(s) or venting to atmosphere?

A boost leak post MAF and/or venting to atmosphere (without the proper setup) would cause less air entering the engine then what has already been read by the MAF, causing you to run rich.


However since you noticed a spike in your AFR at idle, I would lean more towards a boost leak.

and if none of this works, your probably going to need to re tune it.

 

[HOOCH256]

Heading out there meow to do some tinkering on it. But the BOV's are pre MAF to the atmosphere.

 

[codym]

Heading out there meow to do some tinkering on it. But the BOV's are pre MAF to the atmosphere.

Ahh okay I just noticed you're on a maft. Might try giving the settings on that a lookover to see if everything checks out.

 

[HOOCH256]

Bump this up

almost 80 views since last night with no reply?

 

[Beaubo]

I bet you are not getting any more replys because users are waitinig for you to post your findings of suggested solutions.
You said you were going to check on and do some of the things that were suggested but you haven't really answered any of the questions asked or posted your findings of suggested solutions.

What do your plugs look like?
Did you do a boost leak test?

 

[HOOCH256]

I bet you are not getting any more replys because users are waitinig for you to post your findings of suggested solutions.
You said you were going to check on and do some of the things that were suggested but you haven't really answered any of the questions asked or posted your findings of suggested solutions.

What do your plugs look like?
Did you do a boost leak test?

I did update, i just edited the first post., and the plugs look fine nothing out of the ordinary. Checked all the couplers and everything is tight and secure with no leaks

Update 3/3/14

alright guys sorry it took so long to get this updated but i work out of town and my mech was super busy and just now got it in. Now when we had the leak down tester hooked up to cyl 4 you could hear a slight hiss of air coming out of the oil fill cap. but here are the results of the leak down and comp test...

comp test cold
cyl 4- 90#
cyl 3- 95#
cyl 2- 95#
cyl 1- 95#

Comp & leak down Hot
cyl 4- 93# & 18%
cyl 3- 110# & 4%
cyl 2- 110# & 4%
cyl 1- 110# & 4%

 

[Beaubo]

Is this what you did when doing the boost leak test?

https://www.youtube.com/watch?v=fdjadhUP1u4

 

[HOOCH256]

my mech did the testing not myself, and he is a DSM guy so he is familar with the cars but he seems to think that a piston ring is broke

 

[codym]

First of all the compression test should be done with the car at full operating temp, you will not get accurate readings on a cold motor. If your mechanic performed the compression and leakdown test he should know that every single one of those compression numbers you posted are below the service limit.

Even though all are below service limit, Cyl 4 is significantly lower than 1, 2 and 3. With +/- 6psi being the threshold, I would have the head pulled to further investigate IF a proper compression test has been performed yielding the same or similar results.

 

[DSM Chase]

verify compression numbers with another compression tester, ive had readings vary as much as 50psi with a faulty shrader valve in a tester.

 

[Kirkamus]

Here's a few other things I noticed while just driving home. At idle it shows 5# of vacuum. And at idle it's A/F is around 11.5-12 when before it was 14-15. Car runs fine until you hit around 18-19#, if I stay under that you don't even notice it. I normally run the car at 25#




I will check this out, but like I said in my other post is it runs fine till 18-19# then starts to cut out

From this it says your idle is at 5# of vacuum and im pretty sure you should have more than 5# of vacuum. When I start mine on a cold start it has between 14-18# vacuum.

so I would think that there must be a boost leak as well in there somewhere


Or maybe my car has something up with it.

 

[HOOCH256]

Thanks for all the insight, I will call him to relay this info