Top End sputter

[AJ]

Running a stage III ATR setup. Stock injectors. High Flo F/pump.
Boost pegs out at 20 psi.
anything between 16 & 20 psi is causing miss & backfire.
I have to get out of throttle to keep it around 15 to 16 psi.
Have boost control turned all the way down, and have decreased the wastegate adjustment 3 full turns with little results.
Anyone with a similar setup, I would be interested in your settings to find out what works.
Seems to me that it's,
(A) not getting enough fuel at the top end,

(B) Maybe i don't have the wastegate and F/P regulator set correctly to work together to not over boost, and provde the right amount of fuel.

Thanks, any responce is appreciated.

AJ

P.S. I have to say that ATR's Customer service in solving this problem has been quite dissapointing. If your a shadetree mechanic like myself, and count on advice to help you solve problems you run into with thier products..., I don't recommend a purchase from them.

 

[smeagol]

Stage 3 huh? Which stage of detonation is that? I'm assuming that means external wastegate, 3" downpipe and Garrett turbo... right?

Ok, if you keep at the 20psi stuff, you're gonna blow it up. It may be on its way out already.

The ATR gate is a piece of crap, plain and simple. I won't trust it as far as I can throw it.

Ok, don't mean to sound harsh, but do this... don't get into boost with your truck until you do some reading on this site, searching for old posts, reading syty.org archives, etc etc. You will need to catch up here, we've been at this for years now, and there is a LOT for you to learn.

The trucks are hard on ignition and will cause problems there.

They detonate like mad, modifying them can help, doing the wrong modifications will blow up stuff.

 

[AJ]

Brian, thanks for your reply. While I'm somewhat familiar with some of the problems of these trucks,(have had mine since 98) I've been unable to find the solution as to the cause of this overboost since putting in the ATR bolt in stuff last year after my stock mitsi gave out. After calling mutiple times to ATR, they determined that some part of the downpipe had not been ported. They told me to send it in and they would port it and it would fix the over boost problem. Needles to say, it did not. Now, ATR won't even
return my calls. While your not the first person to tell me the ATR wastegates are not good, it's the card that I have and have to play with.
I'm thinking maybe a larger spring inside might help.
I've done some surfing around to find a solution also, but to no avail to this perticular ATR problem.
I know I can't be the only one with this kind of setup?
Again, thanks for your help.

AJ

 

[smeagol]

The wastegate issues can be fixed by (in order of what my preference would be):

a- welding up a new wastegate... you could bring your upper section of downpipe and a real wastegate to a welder/machinist (HKS would be my choice, but Innovative, or Tial would work well too).

b- selling the downpipe, and getting a PTE downpipe & exhaust housing

c- sending the wastegate to Limit Engineering to be rebuilt & fixed

 

[Tydriver]

Re: Top End sputter

Boost pegs out at 20 psi.
anything between 16 & 20 psi is causing miss & backfire.
I have to get out of throttle to keep it around 15 to 16 psi.

My guess, and this is ONLY a guess.. The spark is getting BLOWN OUT, causing a backfire through the intake.

Get some NGK Plugs, and try them, if you insist on running CR42TS's (please tell me thats atleast what you are running) then make sure they are gapped correctly (.035) I would even contemplate cranking them down a little, to say .030 and try it.. Hell its cheap enough to check, I have heard some peeps say on the NGKs, dont gap 'em.. Just install 'em and go...
Thats upto you.. Remember as a plug wears the GAP gets wider and the spark has to work harder therefore 'BLOWING OUT" can occur. Aviation plugs are tested all the time at simulated boost pressure and I can say firsthand I have seen it happen, some plugs WONT LIGHT when gapped incorrectly.

As BG mentioned, these trucks are B*TCHY about ignition problems and an overgapped plug will demonstrate these exact symptoms.. I've seen it, I've done it.

As far as overboosting, well thats upto you. Obviously BG made some stellar points about other issues and you would want to resolve them also, I am not commenting about those, merely the point U illustrated with the 16-20psi deal,
Good Luck hope some of this made sense.

Todd

 

[JSM]

Keep playing with ATR wastegate = blown up engine in near future.

Just because you have a part, doesn't make it USABLE. I had one on my truck for awhile. (borrowed from a friend), needless to say, it was reason his truck blew up, and it was removed from my truck VERY quickly.

That thing might be worth 10 cents (cost of scrap metal). I won't even hold or touch one anymore, let alone install it on ANY truck.

 

[Maverick87]

You have to port the wg outlet of the turbo it is to small also if you run a bigger spring it will get worse I have a 14# spring and boost is under control . With the stage 3 kit you still only have a 2 bar chip so it is not fueling for the extra boost that you can not control

 

[smeagol]

Porting & spring won't solve it always. Glad it solved yours. Rebuilding it by Limit Engineering doesn't always help it.

It will always be a question mark, put it that way.

2 bar or 3 bar, doesn't matter...

 

[Maverick87]

if you put the wg on the crossover would that help

 

[smeagol]

Not really an issue here. Either location will lower turbine pressure, which is what is needed to lower boost level.