06 IX MR

Had the the car almaost 2 months now... not a problem.

TBE ...Forge Wastegate actuator.. Cosworth cams...Boost controller...fuel pump...Flash

Just recently when i floor the car it builds boost but it seems to get slower under boost and stumble..

I checked for any loose couplings... possible boost leak and saw nothing obvious.

I checked plugs and it looked normal...even changed them...

I thought maybe it was a bad batch of gas... So i got some octane booster...still there...

Any thoughts?... This sucks!!.

It feels like i hit a brick wall under boost stumbles... I even hit boost cut once when i persisted...

Boost builds fast under load.... I just dont get it

 

I know you said you checked for a boost but that's what it sounds like.

 

bost leak?...

Forgot to add.... I have a apexi air filter and licp..... Stock uicp. Everything "looks" copasetic...

 

When you say stumble, does the car break up? What are your plugs gapped at? The colder weather might have alos changed your tune and put you in different load cells. If you hit fuel cut, you might want a retune. A boost leak would make you extremely rich, not extremely lean.

 

its got to be boost leak or the plugs.i bought mine with that problem and it had a .40 gap i fixed that and it ran great

 

ya it has factory plugs and they are gapped @ .23

Its like the car is congested.... The engine runs fine al the way to 7k rpms.... provided you are not on boost...

If I boost in any gear... it is really resistant to it. It shudders... feels like it is gonna explode.. It feels like it is trying to force air in but it is blocked???... Only way i can describe it.

 

i would question the Tune. by the way, have you change fuel pump?

 

ya it has a walbro pump....

I am thinking it is the tune as some have suggested....

Thing is i bought the car in Georgia...

It has got down to 25 degrees here in NY over the last week..... So the tune could have been altered ?... Is that possible?...

So do i have to get summer/spring/fall tunes?.... I dont plan on driving it in the winter?....


This Blows *****....!

Thanks,Dave

 

My first thought would be that it's a boost leak, like many have mentioned. This is especially true since you said you hit boost cut when you kept on it. A lot of times, you won't visibly be able to locate them without doing a boost leak check. Also check your vacuum hoses to make sure everything is connected correctly (especially the line going to the fuel pressure regulator).

It's less likely, but issues could also be caused by your tune based on hitting load cells you were previously not hitting during warmer weather. Turbos love cool air, so they spool faster and can push denser air, which in turn increases the load calculated by the ECU. That can put you in cells that a tuner may not have adjusted since they were previously unused.

 

Take it to a tuner and have them check it out (boost leak, knock / timing / fuel map check, etc.)

 

i had a similar problem, and it was the fuel grommet that goes from the top of the fuel pump into the fuel sending unit. the grommet had cracked and i wasn't getting full fuel pressure. might want to check that.

BTW my pump was also a walbro.

Rob

 

UPDATE:

I went to get gas today... Car was on E,... light was on also.....

Car boosted and ran strong in every gear!!!

I went to the gas station and filled up with 93 ( i even went to a diffrent gas station to be on safe side) Once car was full I drove off and same thing happened!!!

Here are more details on what is going on... Under load in 1st 2nd and 3rd gear it sputters and hesitates when boost comes on from 3k on.... And there is black smoke galore while these symptoms transpire.

If i am cruising @ 30 mph or so... Then put it in 4th gear say 2k rpms or 5th @ 2k rpms or 6th etc.... It will build full boost absolutely fine... Till it hits that 3k to 3.5k rpm mark then it starts to break up.

I am lost...... I truly dont think it is a boost leak.... But i realize anything is possible.

Thanks,Dave

 

just for s***s and giggle what boost controller are you using? and what bov are you using

 

tune tune tune....

 

I was just about to post that. I bet it is a tune issue.

Also, gas wont have an effect on building boost.