Help...TTA backfires or pops

[Scott89TTA]

A little info 1st...I'm a complete noobie on these turbo cars and have a ton to learn. I have messed around with cars since the 70's but this is all new to me. I do have a Scanmaster and must admit I pretty much have no clue as to what I am looking at most of the time

We had some nice weather so I pulled the cover off the TTA to take it for a drive. First the battery didn't have enough to start so I jumped it and she started up...hadn't been started since late October. Once it warmed up I shut it off and restarted it a couple of times and it seemed fine. I took it for a short drive and all seemed fine. So I took it out Friday night to meet some local car club friends. Several times while getting on it pretty hard it sputtered and seemed to pop or backfire ? It did this a few times back in October before I put it away for a few months. Now the only thing I have done to the car is add a "Grumpy" MAF pipe and big K&N filter back in Oct. Ever since it has done this on occasion. It also did the same thing right after I purchased it back in May and turned out to be a bad alternator...was only putting out around 11 volts. So now looking at the Scanmaster I'm seeing 12.7-13.5 volts...seem low to me shouldn't I be around 14 volts? So not sure if I'm having problems do to low voltage or something I have wrong with my MAF pipe and K&N filter install since the problem started around the same time. Any ideas what is going on here?

Also by changing from the stock MAF pipe to the Grumpy MAF pipe and a large K&N open conical filter make the boost go up over the stock 16.6 psi ? I ask this because I swear when this thing is running right and it doesn’t backfire the boost looks like it shoots up to around 18-19 on the stock boost gauge. What is a normal reading on the Scanmaster for a stock TTA during hard acceleration (Deg. Retard) ? I hate to admit this but what exactly does knock sound like

Here is the current setup I have.

Any help would be greatly appreciated.
Thanks,
Scott

 

[V8Killer]

1st- Voltage on yor Scanmaster seems ok, that's the range mine's at all the time.

2nd-I had a similar pop/miss under load/heavy accel on my TTA when I first got it, changed coil pack, wires & plugs...problem fixed.

3rd-You shouldn't see any knock on your Scanmaster if all is well. There are a lot of variables there though....chip timing, total boost, crappy gas, etc.

4th-I wouldn't trust your factory boost gauge, hook up a real gauge to see what you have, and if there is a problem.

5th-By the time you actaully hear knock, it's propably doing damage. Enough knock & there goes a head-gasket...poof :frown:

 

[2QUICK2B6]

GRUMPY pipe

What is the diameter of Grumpy's pipe ?

 

[Grumpy]

What is the diameter of Grumpy's pipe ?

3" I would look at the coil pack , wires and such..... Maf goin to 255????

 

[V8Killer]

Got a Hi-po "Grumpy pipe" on my car & no problems here....except goin faster

 

[transampacecar]

I had the same problem and it was the coil pack

 

[TClassic]

With the Extended pipe you have to "MAKE SURE" your MAF isn't resting on the HOT Radiator hose where it bends!!

 

[Scott89TTA]

With the Extended pipe you have to "MAKE SURE" your MAF isn't resting on the HOT Radiator hose where it bends!!

Pretty much sitting right against it...come to think of it this problem might only be happening when the car is good and warmed up I believe but i'm not possitive? I was looking at the Scanmaster Friday night and one of the readouts said "HOT" but it was late and I'm not 100% sure what I was looking at so I can't say for sure which one it was but could have been MAF maybe? It didn't show up "HOT" when I went throught the modes again.

 

[V8Killer]

As heat increases so does resistance, which makes it harder to fire the plug & more likely to misfire/pop. This happens on all cars, but is worse on a turbo car under boost.

 

[Louie L.]

Did you bang the MAF around when you installed the new pipe combo? They are very sensitive. The cam sensor interuptor disc should also be checked for movement.

How much was the Grumpy pipe..it looks very nice..

 

[Scott89TTA]

Did you bang the MAF around when you installed the new pipe combo? They are very sensitive. The cam sensor interuptor disc should also be checked for movement.

How much was the Grumpy pipe..it looks very nice..

I don't think I banged the MAF around but it is a tight fit.

PM on the Grumpy MAF pipe.

 

[Scott89TTA]

Well after talking to John Pearcy about the problems I was having with sputtering and popping at WOT, over boost (19-20+PSI) and 19-22+ nock retard on the scanmaster. He suggested I do a few things.

This is what he suggested...
1. sputtering & popping: replace plugs (AC R42KTS gap .035) and wires (MSD 3199).
2. overboost 19-20+ psi and >19 knock retrard, new 3" MAF w/big K&N filter is allowing the turbo to spool up easier, quicker and making more boost...turn down the boost: install adjustable wastegate accuator.

We had 60 deg. weather here in MD today so I decided to try and fix some of these problems (car has only been driven twice since mid October). Well pulled the heat shield and removed the stock wastegate accuator. This is when I found that both vacuum lines after the "Y" were cracked and split. The one going to the turbo output was was almost broke in half...big leak. replaced all lines. Installed the new adjustable accuator then moved on to the plugs. Old plugs looked good in color (light brown/tan) but the gap was .040+ on all 6 (guessing these were the stock plugs). Installed new plugs gapped .032+, at the time I couldn't remember the recommended gap, I was talking to Dan "Grumpy" on the phone about the accuator and other stuff at the time and he recommended .032 gap. Did not have time to do the wires since the MSD 31199's need to be cut to length. Results Idle is better and no popping or sputtering even at WOT. I have been playing with the adjustable wastegate accuator, at first I was getting 20 psi and 19 knock retard, gave it a few turns and it went down to 10 psi no knock reatard. I turned it back up some and think it is around 15-16 psi now and sometimes it shows zero knock retard and sometimes it will show 2-8 knock retard, I'm wondering if my gas is not so good at this point. I would think I should be abale to get 16-18 withour knock on 93 octane gas shouldn't I

Anyway it looks like I'm on my way to correcting the problem, thanks to John and Dan for all their help...I'm still learning but I'm slowly getting it

Put about 20 miles on the car today and an couple of hard runs...feels much better, I'm sure the wires will help some more as I did get a pretty good shock from one while checking to see if they where on tight with the car running

Scott

 

[cottonpicker14]

Long MAF pipe looks great. Other than looks, does it make any difference in peformance ?

 

[TTA850]

I have been playing with the adjustable wastegate accuator, at first I was getting 20 psi and 19 knock retard, gave it a few turns and it went down to 10 psi no knock reatard. I turned it back up some and think it is around 15-16 psi now and sometimes it shows zero knock retard and sometimes it will show 2-8 knock retard, I'm wondering if my gas is not so good at this point. I would think I should be abale to get 16-18 withour knock on 93 octane gas shouldn't I

What chip are you using? If it's still stock or an older aftermarket chip that could be a problem.

 

[Scott89TTA]

Long MAF pipe looks great. Other than looks, does it make any difference in peformance ?

Grumpy's 3" MAF pipe combined with the K&N RX-3990-1 X-Stream filter (~850 cfm) I noticed a pretty substantial gain in power right away. This is mostly do to removing the restrictive factory air box and elbow...but I'm sure the 3"MAF pipe helps to move the air along smothly as well. Problem for me was I didn't have a adjustable wastegate accuator and my boost went up to ~20 psi and so did my knock retard. As stated I installed a new adjustable wastgate acccuator and pretty much solved that problem. Definitely spools up faster and sound real cool as well

What chip are you using? If it's still stock or an older aftermarket chip that could be a problem.

stock chip...until the addition of the Scanmaster, MAF pipe, K&N Filter and Adj. Wastgate Accuator the car was 100% stock...44K miles.

I'm planning on a few other mods shortly which would include a chip as well as...MSD 50's, 340 Walbro, Billet adj. fuel reg., Julio's Alky kit, 3" Accufab S/S DP w/electric dump, 100 lb valve springs, RJC power plate, Art Carr shift kit, trans cooler, and a bunch of other little things.
Lets just call it Razzor's resapie for low to mid 11's with some help from Grumpy and John Pearcy

 

[TTA850]

A good chip should help, I used Thrashers on my old stock TTA's and got an 11.99 @ 113 out of the car stock with just the mods you've already done plus a set of ET Streets, dump pipe, and 22psi on racegas. If I were to do it again I'd go with a turbotweak chip right from the start, and belive with the adjustability of his chips and a torque converter that actually locked it would have went considerably quicker. Too bad that car is gone and I cant prove it.

Anyway just my opinion, good luck sounds like your heading in the right direction.

Steve