Hey guys,
Does this happen to anybody else? I finally licensed my car yesterday, unhooked everything after it finished reading. And when i started the car, it didn't start the first 2 tries, and then when it did, it hesitates before it revs up.
Heading to work in 10min, hope theres no problems along the way, but curious if anybody else has had this happen. Is there a fix?
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
Everytime after I write a new flash to my car, it will stumble at 1500RPM under light throttle, I watched the sensors and found the TPS to not be reading when I give part throttle, and causing the stumble. After a few sharper revs through the stumble, it would learn and the problem goes away.
My issue is likely due to my bored out TB (the plate sits at a different angle when closed than stock, and the TPS had to be modded to make it read 0% at idle). Basically, if you have anything out of spec that the ecu is compensating for, it will need to relearn before it's able to compensate again.
15.3 @ 89.97mph, 14's on the way?
Ian Brydon wrote:Everytime after I write a new flash to my car, it will stumble at 1500RPM under light throttle, I watched the sensors and found the TPS to not be reading when I give part throttle, and causing the stumble. After a few sharper revs through the stumble, it would learn and the problem goes away.
My issue is likely due to my bored out TB (the plate sits at a different angle when closed than stock, and the TPS had to be modded to make it read 0% at idle). Basically, if you have anything out of spec that the ecu is compensating for, it will need to relearn before it's able to compensate again.
mm.. i have teh 60mm tb aswell. Maybe with hpt we can fix this.
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
i have the same problem, i have the stock tb...
sometimes the car wont even stay on unless i hold the gas down for a few minutes, yea, minutes! but only after a hptuners reflash.... weird...
|Forged 8.9:1 Wiseco Pistons|Forged Eagle Rods|HPTuners|60trim|Tial Wastegate|
|Precision Intercooler|2.5" Exhaust|2.5" Charge Pipes|630CC Mototron Injectors|
|Stock: Fuel Pump, Transmission, Manifold, TB, Head, Head Gasket, Ignition, Suspension...|
I'm bumping this thread from the dead, as it's become an issue for me again, different car, and much worse.
'04 ecotec SC auto, trying to get the HPTuners up and running on a 2nd ecu with the base tune for the car modified to work with the 2.5 MAP sensor. After every re-write, the car won't run right, it stumbles and hesitates, wants to stall, and the wideband shows very high or off the chart lean conditions when trying to rev in park/neutral. If you try to drive it, it will either stall or stumble, it takes a few minutes of reving to get things sorted out. The TPS shows that it only picks up a range of 9% at idle to 86% at WOT, I feel this could be a major part of the issue. I've tried several times to do a case learn via the HPTuners program, but I can't seem to get it to work, any insight?
15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
After flashing the computer it is a good idea to unplug the battery for a half hour or so to let the computer to reset. That is what i do because if i dont the computer gets real ignorant .
245hpcavy wrote:After flashing the computer it is a good idea to unplug the battery for a half hour or so to let the computer to reset. That is what i do because if i dont the computer gets real ignorant .
How in the world is that going to work if you are tuning on a dyno? There has to be a better solution, but thanks for the response.
15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
Yea your right i was just trying to help..
245hpcavy wrote:Yea your right i was just trying to help..
It is appreciated!
15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
no you don't have to unplug the battery, you just have to follow the procedure. After the flash simply turn the key back all the way then start. you have to turn the car back off first you cant just start it from the on position it was in while you did the flash.
Very true!! Maybe that is whats happening when they are flashing his computer..
K. Vega..Mr. M62 L61 himself. wrote:no you don't have to unplug the battery, you just have to follow the procedure. After the flash simply turn the key back all the way then start. you have to turn the car back off first you cant just start it from the on position it was in while you did the flash.
thats what i have always done....by coincidence, and I have never noticed the problem you guys are describing.
I made a post about this awhile back i belive. When i flash mine, it wont stay running for about 15 to 20 mins. It does it really really bad. Then after touching the gas to help it stay running it will finally stay on. I hate reflashing.
ive noticed the no start after the reflash too. what i try and do is turn the ignition to the off position, pull the key (not really needed but...) then i start the car.
the stumble when it starts is more than likely because of the fuel trims. has been an on going problem. if your STFT arent dialed into where they should be, your car will have to relaern them the hard way.
1997 Cavalier Z24 - 15.647 @ 88.02 MPH
I've been doing the pull the key before starting the car thing all along, I have forgotten in the past, and the results are very similar to this, but it's not being triggered by not pulling the key after flashing. Thanks for the ideas.
15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
Each reflash you do, the ECU has to go through its relearn. ALL fuel trims are reset too.
----------------------------------------------------------------
www.bradsairsoft.com
CheesyPackerFan wrote:Each reflash you do, the ECU has to go through its relearn. ALL fuel trims are reset too.
That shouldn't be such a big ordeal that the car won't even barely run though, none of the other cars I've used HPTuners with have done this poorly. This is the 5th J-body we've tuned, and none of the others were anywhere near this bad.
15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
Bump for some insight.
15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
have you tried to reflash the stock file back to the car?
K. Vega..Mr. M62 L61 himself. wrote:have you tried to reflash the stock file back to the car?
Nope, I guess that would be the next step, make sure it does this for all writes and not just the modded ones. We are using a spare ecu for the hptuners bit, and the other one has the GMSC flash on it. The stock file won't be provisioned for the 2.5bar MAP though, not sure how it will react to that.
15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
well go to hpt histogram site and d/l another file with the stock s.c reflash on it and work from there why would you rather work with a non boost n/a tune opposed to a stock boost tune straight from gm? unless I am missing something here.
K. Vega..Mr. M62 L61 himself. wrote:well go to hpt histogram site and d/l another file with the stock s.c reflash on it and work from there why would you rather work with a non boost n/a tune opposed to a stock boost tune straight from gm? unless I am missing something here.
Unless I am missing something, you can't read/edit the GMSC tune for the ecotec, so you have no choice but to work from the NA tune.
15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
well 1st off according to his profile he has a ld9. that reflash can be read.
2nd the gm reflash can be logged just not worked on.
K. Vega..Mr. M62 L61 himself. wrote:well 1st off according to his profile he has a ld9. that reflash can be read.
2nd the gm reflash can be logged just not worked on.
Who's profile? I'm tuning an eco with the GMSC, so that's the application I'm having problems with. 2nd, I'm not trying to log anything when I'm having the problem, it's when I write a new tune to the ecu that it screws up.
15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
Ian Brydon wrote:K. Vega..Mr. M62 L61 himself. wrote:well 1st off according to his profile he has a ld9. that reflash can be read.
2nd the gm reflash can be logged just not worked on.
Who's profile? I'm tuning an eco with the GMSC, so that's the application I'm having problems with. 2nd, I'm not trying to log anything when I'm having the problem, it's when I write a new tune to the ecu that it screws up.
Please send me the tune.. Email it to
pnptuning@gmail.com .. The GMSC Eco flash is not able to be tuned due to checksum errors. I want to see exactly what tune you have. I will not share it with others, I just want to see if I can help you out..
P&P Tuning
420.5whp / 359.8wtq
