Hesitation in 4th gear around 2000 rpm
05-26-2005, 05:07 PM
#1
Hesitation in 4th gear around 2000 rpm I just got done a cam swap and everything went fine. I was able to drive it with no unexpected problems. Just a bad idle and a basic need for a tune.
Long story short…After I got a tune, my car hesitates in 4th gear at around 2000 rpm. You only feel the hesitation when your cruising around at the same speed (2000 rpm) and you put the peddle down about 50%. What would cause this and how do I fix it? Is there something in the VE tables the tuner messed up? What do you guys think? Think I should just learn to live with it?
Keep in mind I didn’t have a hesitation problem after the cam install, only after the initial tune. The “long story” is below if anyone’s interested = )
******
I got an appointment for a tune at FbodyCenral in Baltimore MD and after uploading tunes to the computer many times, the car wouldn’t start almost every time. It was late on a Friday and I was coming back for a dynotune later anyways so they said when you come back for the dynotune we’ll fix all the issues. After around 2 hours of tuning, I still had the rpm’s hang at around 1500 rpm after putting the clutch in and I’d also have some hesitation in 4th gear at around 2000 rpm. They did get it to start up and stay at around 900 for the idle so I went home waiting for the dyno and tune.
When I got home I put the stock maf back like they said to and the car idled much smoother, but I still had hesitation and it still stuck at 1500 rpm. The SLP MAF caused a few problems so I took it out.
When I got there the second time for the dynotune to fix the problems, I had to wait around an hour for their tuning guy to get there. When we drove around tuning it, he told me he could fix the rpms sticking, which sort of did. But he tried giving me some lame excuse about the hesitation, which didn’t fly. He then admitted it was something he should fix. He put it off fixing it because we had to make it over to the dyno shop (they don’t have a dyno). We did some pulls and got decent numbers considering my mods. After the dyno they said go drive the car and if you still have hesitation, come back and the president of the company will drive it to see what’s going on. He drove it around and it still hesitated in 4th. so he tried giving me the lamest excuse I’ve ever heard, which was the suspension was starting to get under load at that one time causing body flex. Weird that it didn’t ever have the problem before the tune isn’t it? I didn’t even have the problem after I put the cam in. Only after the horrible tune.
Basically, I had a very bad experience with the tuning at Fbodycentral! They don’t seem to know what they’re doing!
EDIT/UPDATE: I took my car back to Fbody Central and told them to put my computer back to stock and then retune it. They did a great job on the tune this time around and I'll feel a lot less apprehensive about going there now.
FWIW: I think the hesitation was due to some unnecessary tuning in the MAF table which was put back to stock when I had my computer flashed back to stock.
Long story short…After I got a tune, my car hesitates in 4th gear at around 2000 rpm. You only feel the hesitation when your cruising around at the same speed (2000 rpm) and you put the peddle down about 50%. What would cause this and how do I fix it? Is there something in the VE tables the tuner messed up? What do you guys think? Think I should just learn to live with it?
Keep in mind I didn’t have a hesitation problem after the cam install, only after the initial tune. The “long story” is below if anyone’s interested = )
******
I got an appointment for a tune at FbodyCenral in Baltimore MD and after uploading tunes to the computer many times, the car wouldn’t start almost every time. It was late on a Friday and I was coming back for a dynotune later anyways so they said when you come back for the dynotune we’ll fix all the issues. After around 2 hours of tuning, I still had the rpm’s hang at around 1500 rpm after putting the clutch in and I’d also have some hesitation in 4th gear at around 2000 rpm. They did get it to start up and stay at around 900 for the idle so I went home waiting for the dyno and tune.
When I got home I put the stock maf back like they said to and the car idled much smoother, but I still had hesitation and it still stuck at 1500 rpm. The SLP MAF caused a few problems so I took it out.
When I got there the second time for the dynotune to fix the problems, I had to wait around an hour for their tuning guy to get there. When we drove around tuning it, he told me he could fix the rpms sticking, which sort of did. But he tried giving me some lame excuse about the hesitation, which didn’t fly. He then admitted it was something he should fix. He put it off fixing it because we had to make it over to the dyno shop (they don’t have a dyno). We did some pulls and got decent numbers considering my mods. After the dyno they said go drive the car and if you still have hesitation, come back and the president of the company will drive it to see what’s going on. He drove it around and it still hesitated in 4th. so he tried giving me the lamest excuse I’ve ever heard, which was the suspension was starting to get under load at that one time causing body flex. Weird that it didn’t ever have the problem before the tune isn’t it? I didn’t even have the problem after I put the cam in. Only after the horrible tune.
Basically, I had a very bad experience with the tuning at Fbodycentral! They don’t seem to know what they’re doing!
EDIT/UPDATE: I took my car back to Fbody Central and told them to put my computer back to stock and then retune it. They did a great job on the tune this time around and I'll feel a lot less apprehensive about going there now.
FWIW: I think the hesitation was due to some unnecessary tuning in the MAF table which was put back to stock when I had my computer flashed back to stock.
Last edited by Xtnct00WS6; 09-12-2005 at 11:17 AM.
05-27-2005, 12:47 AM
#4
I had a tip in trottle hesitation similar to what you describe after I pulled the screen out of my MAF and ported my TB. If you did either of these or messed with the MAF table for fuel enrichment, that is what did it. Put the MAF table back to stock and do the fuel curve with the PE table and IFR table. If you messed with the MAF or TB put in the Z06's MAF table to tell the PCM to expect more airflow.
I am sure they tried to mess with the MAF table and that is where the problem is. The hangng idle is a throttle follower adjustment. I would have them flash it to stock and re-tune elsewhere.
I am sure they tried to mess with the MAF table and that is where the problem is. The hangng idle is a throttle follower adjustment. I would have them flash it to stock and re-tune elsewhere.
Last edited by Spinmonster; 05-27-2005 at 12:56 AM.
05-27-2005, 08:34 AM
#7
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did u have nock, these cars with a cam sometimes have nock under load right around 2k rpm or right below it, sounds like ur tunner pull timing in that particular rpm
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05-27-2005, 02:46 PM
#8
Nah…I don’t have any knock. I do most of my driving at around 45 mph so this is getting very annoying!
Spinmonster, I think you’re probably right. We had a lot of trouble with the maf because when I first had them tune my computer, they were thrown off by the SLP Maf so I'm sure they changed something in there! For those who don't know the SLP Maf tricks your computer which will in turn trick you when you trying to tune it if you don't know what your doing. When I drove home that first night after the initial tune, that’s when I noticed the hesitation. I put the stock maf back on and it’s still there though. I just still can’t believe the guy tried to pass it off as a suspension problem.
What do you guys think about putting thunder racings Maf on it that utilizes the stock electronics and having them set the Maf table back to stock?
Spinmonster, I think you’re probably right. We had a lot of trouble with the maf because when I first had them tune my computer, they were thrown off by the SLP Maf so I'm sure they changed something in there! For those who don't know the SLP Maf tricks your computer which will in turn trick you when you trying to tune it if you don't know what your doing. When I drove home that first night after the initial tune, that’s when I noticed the hesitation. I put the stock maf back on and it’s still there though. I just still can’t believe the guy tried to pass it off as a suspension problem.
What do you guys think about putting thunder racings Maf on it that utilizes the stock electronics and having them set the Maf table back to stock?
05-28-2005, 01:34 AM
#9
Originally Posted by Xtnct00WS6
Nah…I don’t have any knock. I do most of my driving at around 45 mph so this is getting very annoying!
Spinmonster, I think you’re probably right. We had a lot of trouble with the maf because when I first had them tune my computer, they were thrown off by the SLP Maf so I'm sure they changed something in there! For those who don't know the SLP Maf tricks your computer which will in turn trick you when you trying to tune it if you don't know what your doing. When I drove home that first night after the initial tune, that’s when I noticed the hesitation. I put the stock maf back on and it’s still there though. I just still can’t believe the guy tried to pass it off as a suspension problem.
What do you guys think about putting thunder racings Maf on it that utilizes the stock electronics and having them set the Maf table back to stock?
Spinmonster, I think you’re probably right. We had a lot of trouble with the maf because when I first had them tune my computer, they were thrown off by the SLP Maf so I'm sure they changed something in there! For those who don't know the SLP Maf tricks your computer which will in turn trick you when you trying to tune it if you don't know what your doing. When I drove home that first night after the initial tune, that’s when I noticed the hesitation. I put the stock maf back on and it’s still there though. I just still can’t believe the guy tried to pass it off as a suspension problem.
What do you guys think about putting thunder racings Maf on it that utilizes the stock electronics and having them set the Maf table back to stock?
