I just got Brenspeed's Stage 3 Saleen Kit installed and the car is acting funny. Brenspeed is working onthe issueto see if it is in the tune, but I was wondering if anyone with any Twin screw charger who is running colder plugs can tell me if their acts like this. When I first start the car and drive away after it has been sitting like all night or the car cools down all the way it almost feels like it hesitates and kind of drowns in 1st and 2nd. But as soon as the car gets to temperature it goes away and the car seems to run fine. I have 20 degrees of vacuum, I have tried swapping out to the stock plugs and the car acted the same. Any help or advice anyone could give is appreciated?

ORIGINAL: silver05gt1

I just got Brenspeed's Stage 3 Saleen Kit installed and the car is acting funny. Brenspeed is working onthe issueto see if it is in the tune, but I was wondering if anyone with any Twin screw charger who is running colder plugs can tell me if their acts like this. When I first start the car and drive away after it has been sitting like all night or the car cools down all the way it almost feels like it hesitates and kind of drowns in 1st and 2nd. But as soon as the car gets to temperature it goes away and the car seems to run fine. I have 20 degrees of vacuum, I have tried swapping out to the stock plugs and the car acted the same. Any help or advice anyone could give is appreciated?


I can give you this comfort: I have exactly the same set up and mine does exactly the same thing on cold days (year round DD here). There is a bit of hesitation when I give it some good pedal within the first 3-4 minutes after cold start. This is the only time it does this and it's pretty mild.

I'm thinking the mixture is a bit rich (the 'safety factor'), and the engine a bit cold which makes the mixture even richer so you get the 'stumble'.

I just live with it as I don't believe nailing the throttle on a cold days with a cold engine would be the wisest course of action vis-a-vis engine longevity. I'm sure it could be fixed by leaning the A/F in the tune but then....

Be interested to know how you come out. You might mention to Daveand Brentwhat I wrote above.

How'd your numbers come out on the dyno?

Thanks 2007GT. That actually does make me feel better. I was kind of freaking out you know. New system, no problems like this before install, then installed and it started. So I thought for sure that the shop left something disconnected or something.... Brent and Dave told me they are going to look and see if they can safely change anything, but like I told them I would rather let the car warm up 3 minutes thencause damage to the motor. As far as dyno numbers go, I wish I could tell you. The closest dyno to me is 3 1/2 hours away. So until I can get a day off to get to Dallas I don't know what the car does. I am ready to find out though. My numbers should be pretty close to yours we have a pretty similar setup. But I know every car is different.

Read up on Spark Blow out. I just read about it today, that could be your problem. You could try a set of aftermarket COPS. Also you should really let the car get up to temp before getting into the boost at all.

Good luck I hope you get it sorted.

I had this exact same issue using brent's tune. ( you should be able to search the several threads on this issue) They never did solve it I put up with it for several months. I would feel it in the pedal. I replaced COPS, FUEL system lines plugs twice. I put tons of money at the problem. Lucky for brent my input shaft snapped. Got the car tuned byS.T motorsportsand I have 0 issues none nothing. No hesitation the car gets up and goes. I sent several datalogs they never found anything. According to brenspeed they put this exact tune on tons of car's so there is something wrong with your car not the tune.

For a long time I didn't think the tune had anything to do with it.

Mine does the same thing when its cold but I never even considered it a problem. After it warms up, runs great.
If it does something after it warmed up then you might have issues.
Have fun.....

MustangGT0405, that is why I am confused. I already have MSD coils on the car. And as far as getting in it when it is cold. The problem I have happens at like 2000 rpms driving 20 mph, so it is not because I am getting in it. I will just try to pull away from a stop sign and have the problem. Pretty much when it is cold anything more then 1/4 throttle and it spits and sputters. And sevenleaf, that is pretty much what Brent and the guys are asking me to do now. Is send them datalogs and see if they can find anything. But based off of what I am seeing here it doesn't look good. Of course as helpful as Brent and Dave have been they also told me I was the only person, aside from one other guy, who has this problem.Like I said the only place close for me to take my car to is Dallas Mustang. And I am not sure how good their tunes are in comparison. If anybody has experience with their tunes please chime in.

I never had the issue when I had mine. i did not have the brenspeed tune, plus I do live in Florida so cold starts are few and far between....well of course there are cold starts...but I mean where outside air temps drop below 50,.....I never had the issue though..sorry...

welcome to the world of ECU tunning. had the same problem on my sentra ( lol i know) basically the ECU uses different fuel/timing maps depending on Engine temp and can even in some cases cross ref fuel/timing maps and make educated guess on how much fuel/timing to run. the tunes you have most likely don't fully address this. this is very common when u get a reprogrammed ECU. its extremely hard unless you know the coding inside and out to get the car to 100% driveablity all the time.

ORIGINAL: silver05gt1

MustangGT0405, that is why I am confused. I already have MSD coils on the car. And as far as getting in it when it is cold. The problem I have happens at like 2000 rpms driving 20 mph, so it is not because I am getting in it. I will just try to pull away from a stop sign and have the problem. Pretty much when it is cold anything more then 1/4 throttle and it spits and sputters. And sevenleaf, that is pretty much what Brent and the guys are asking me to do now. Is send them datalogs and see if they can find anything. But based off of what I am seeing here it doesn't look good. Of course as helpful as Brent and Dave have been they also told me I was the only person, aside from one other guy, who has this problem.Like I said the only place close for me to take my car to is Dallas Mustang. And I am not sure how good their tunes are in comparison. If anybody has experience with their tunes please chime in.


Well I was going to say my car runs a bit rough when cold, but nothing like you are describing. If I had just robbed a bank and needed to make a quick getaway, I'd have no worries even if it was a dead cold engine.:D

Mine does this also, I blamed it on the delete plates or the colder plugs, it didn't bother me enough to complain about it just figured it went with adding so many different things to the engine. After about a mile driving it's fine. Some days it seems a little worse then others.

ORIGINAL: sevenleaf

I had this exact same issue using brent's tune. ( you should be able to search the several threads on this issue) They never did solve it I put up with it for several months. I would feel it in the pedal. I replaced COPS, FUEL system lines plugs twice. I put tons of money at the problem. Lucky for brent my input shaft snapped. Got the car tuned byS.T motorsportsand I have 0 issues none nothing. No hesitation the car gets up and goes. I sent several datalogs they never found anything. According to brenspeed they put this exact tune on tons of car's so there is something wrong with your car not the tune.

For a long time I didn't think the tune had anything to do with it.


Its in the tune. I had that same issue the there tune when I was N/A and then had the same issue with a tune with my procharger that time not tuned by Brenspeed but by some one else.

I am now tuned by Adam from ST and have zero cold start issues and the car runs like it did when it was stock but with excessive amounts of hp

Why dont you try a VMP tune?

Or if it goes away, you might just have to live with it until you make the trip somewhere. There has to be some really good tuners in Texas. Make a vacation out of it.

Good Luck

There are 2 places in Texas that I know of, of course 1 being Dallas Mustang, and the other being a place called Triangle Speed Shop. Both are about 3.5 hours from me.I have been to Dallas Mustang when my car just had a couple of bolt ons and they seem to do pretty good, so I am thinking about going back to them and see what happens. But at this exact second I don't have the $500 to go do a tune. So no matter what happens I will have to wait a month or so and just deal until then. I want to make a trip over there anyway so I can see what kind of numbers the car is putting down. Also, It sounds to me like S.T. Motorsports must know what to do. I have been told by like 5 people now that they fixed the tune tune that they have were having problems with. To bad Cal. is to far away.

I have a tune from Dallas Mustangs. I love it but...I've never had any other tune from anyone else, so I really can't compare. I havn't had any issues with the tune though. The tune is probably pretty conservative. I'm actually going to get gears installed there tomorrow. I hope the install goes well!

I would say bring the car to get it dyno tuned. I used Tillmanspeed, who I had bought my xcal2 from, but I'm N/A (for now).Yourproblemsounds like a tune issue to me.