Car runs fine normal throttle but floor it and machine gun sound!!

[AL92]

I got my car a week ago and it was running really bad would barely idle,idle surging and could hardly drive it around at any throttle setting it would surge and sputter and buck a bit.

Since then put in redline injection cleaner,premium 92 octane,new battery,new air filter,new fuel filter,new pcv,new therm,new accel wires and new ngk plugs.Did Mopar CCC to the car and then engine flush and new synthetic oil.Checked timing and tps and timing was way out but is stock now.Checked upper hoses on intercooler tighten them all up and even checked exhaust manifold for big cracks.Turbo spins up and seems to be boosting fine at part throttle but go full throttle and machine gun sound and car don't go at all.

Vacuum was steady at around 16 or so..am at 2000ft above sea level.

Took off cat and catback also to make sure wasn't clogged cat.

Tested ignition coil seems ok and tps.

What the heck is left to check here.What would cause this machine gun sound and no power at wot.Can a bent valve car pull steady vacuum have perfectly smooth idle and run fine not wot???

No check engine lights either.Nada..

Haven't checked my underneath intercooler pipes yet and haven't checked fuel pressure.

Appreciate any help you guys can give.I even ordered mods for car thinking the problem was just a tune up but starting to wish I hadn't bought this thing.Its undriveable the way it is.

 

[Tsi21]

sounds like a spark problem
Ive heard of accel wires sometimes crapping out at high rpms
not often, mind you, but ive heard about 3 or 4 cases
Mis firing may be a small type of pre detonation if ur timing is a little off and may make that machine gun sound
check ur wires and/or coil pack
Not sure if this is the solution but from what u describe its the first place i would look

 

[leet]

This may sound wierd, but have you checked for boost leaks?

 

[AL92]

Checked top intercooler hose and tighened up all clamps and checked for any holes.Havne't gotten under to look at bottom and really check out intercooler yet though.Will do that soon.

 

[timmy]

Replace with NGK plugs and wires, and it will fix you prob

 

[AL92]

Have ngk iridiums brand new and accel wires brand new so will see if they are a problem by swapping in some cheap ngk and borrowing buddies wires.I really doubt the wires and plugs are the problem.

 

[Defiant]

Originally posted by AL92
Have ngk iridiums brand new and accel wires brand new so will see if they are a problem by swapping in some cheap ngk and borrowing buddies wires.I really doubt the wires and plugs are the problem.

Iridiums and platinums aren't recommended for turbo cars, go with regular old stovebolt copper core NGKs in a 6 heat range, gapped to .028.
Do you have any exhaust leaks?

 

[AL92]

Well ngk recommends them..even has specific part number for them as does denso and lots of turbo cars are running them with good success.I am only at stock boost right now so you would think they should be fine with that.
Still due to many people who swear by the cheap ngks I will be throwing some in to see what diff it makes and trying some other wires.
The car was doing the same thing with cheap ngk although not sure how used they were and with other wires athough couple of the other wires looked not to match the car.

I took off entire cat and behind it and am just running downpipe until new apexi system goes on in next day or so.So not much exhaust left to leak.Exhaust manifold seems uncracked.

Will try the pressurized leak tester thing shortly and see what leaks can be found.

This is very frustrating problem to have next to no power at all.Car is basically undriveable.Really hope can get it figured out.

 

[Megags]

Sounds like spark, could also be valve timing. Does your bov make a choppy whistling sound?

 

[AL92]

Well tonite after finding out parts dumbo had given me two non turbo and two turbo iridiums for my car and buddy who didn't really check and I confess didn't either just put them in.I pulled the wrong plugs out expecting for how bad the car has been running to find them totally black or oil fouled or broken from bent valves or something.Instead they looked fine and reasonabley clean.Didn't bother pulling the two correct iridiums.
Also made sure the plugs were in right not crossthreaded and tightened properly and made sure the new accel wires clicked on to the plugs.Not sure buddy really made sure they were on to tell the truth.

Gap is way higher on the non turbo ones so guess they just blow out as soon as the boost starts coming out.
I bought some nifty tower testing things at auto store.You put them in between your wires and plugs and they flash as the plugs spark.I revved the car in driveway and they flashed smooth no problems.
I then took car for good test drive on our terrible horrible icy as heck roads on my worn out crappy tires and managed to still punch it out a few times and guess what she hauled freaking ass.I knew if I totally kept it floored would hit a parked car or post for sure and before if I floored it just dogged and felt like a big lawnmower.!!

So now have other problems..How do you guys with keep these things on the road in winter with 300 hp or more
And have to say this but I think my talon handles very bad.It feels floaty and too high and sort of wobbly? when you throw wheel from side to side.Not sure whats up with that or if need any parts under there but will give them a once over shortly.And then its time for eibach pros,kyb agx,sway bars and shock towers and poly bushings to make this car handle as good as it goes now with just stock boost and open downpipe!!

And now sure will be impressed even with simple boost mod and other basic mods but sure hope the roads improve around here.
And then come spring thaw its time for new turbo and big power..

 

[AL92]

Oh and guys I think some of you should be more open to the iridiums over the cheap ngks.They can work fine.And if you read the newest mags many many cars putting out sic power are using ngk or denso iridiums.NGK needs to offer some colder heat range iridiums like denso does.And its platinum that is usually not recommended for nos and turbos not iridium.

 

[leet]

I use Iridiums on my car. I have NEVER had a stuttering/lack of power issue with them. I am also using Magnacor wires.

 

[AL92]

The bog at wot demon is back today..don't hear the machine gun noise but floor the car and it bogs.I would say anthing much past 1/2 throttle.Keep the throttle under half and car boosts and moves out good.

So the proper gap iridiums didn't fix problem after all.

Next part going in.ordered new coil have good amount of miles on car so figured its a good idea anyway.

After that fuel pump..

After that well not sure going to order new turbo and fmic and injectors
anyway and after all that the bog when wot better be gone....

 

[BISHILVR]

replace your knock sensor!!!!!

 

[mitch83]

did you check to see if oil was on the washer that rests on the head because water or oil on those washers will ground out the plug and cause a miss fire(had that problem). Also the way you describe the new problem did you check to see if your MAF was plugged in(had that problem as well). I dont see the knock sensor causeing that problem
. check the cheap stuff first before buying all the other big stuff.
mitch

 

[my95tsi]

Originally posted by AL92
Oh and guys I think some of you should be more open to the iridiums over the cheap ngks.They can work fine.And if you read the newest mags many many cars putting out sic power are using ngk or denso iridiums.NGK needs to offer some colder heat range iridiums like denso does.And its platinum that is usually not recommended for nos and turbos not iridium.

Its not that the iridiums are bad its just that they are not needed. To get optimal performance the NGK-R bpr7es or 6es are great. Iridium are just a waste of money. Honda guys like to use them b/c they try all they can to get an ounce of a horsepower but for a dsm its just waste of money.

 

[mark95turbo]

Might want to check your ECU for leaking caps too. If you have a buddy with a DSM see if you can borrow his ECU. Doesnt matter if his car is FWD AWD as long as its turbo and has the same tranny (auto\5-sp.) Good luck!