chrly924s

Has anyone had any problems w/surging or 'bucking' on trailing throttle? I had this problem when I got the car but replacing all vacuum lines, venturi delete, throttle reseal, etc, I eliminated this problem. Everything was fine until I put the new chip in. I have adjusted the idle because it was at 1200 rpm. now it's at about 1000. The car idles smother there. Could this be the problem. Other than that the chip is awesome. I've already gotten a speeding ticket

chrly924s

The car is an 87 951; no cat, flowed stock injectors, 3 bar FPR, LBE, Flowmaster exhaust. Thanks.

xsboost90

havent had any problems w/ my max chips.

Luis de Prat

I did. My DME was shot. The chip ran great until after about 40 minutes and then the car would run terribly, bucking and backfiring. Managed to find a good used DME and am using it stock. Having it rebuilt to finally enjoy that phenomenal chip.

LFA951

I've had a similar problem, I got the Max chip for my Autothority MAF with a 30C calibration and the chips it came with, leaned out in higher gears on throttle, so Russ sent me some 30C and it felt faster accelerating, but when cruising in 4th or 5th, it would buck when I coast then accelerate gain, that's cause the chips max out your injectors at all ranges of the rpm, even when you're not flooring it. It also raised my idle by about 200 rpm right off the bat, I'm at around 1,100 and I left it there. I'm gonna see how it goes this week with them, but what you are experiencing is normal I guess, but the idle speed has nothing to do with the bucking or surging as you put it.

chrly924s

Thanks. I guess I will just have to live with it.

xsboost90

did you ask russel about this? he is very helpful - ive talked to him many times.

LFA951

I talked to him and like I said he sent me another set of chips, I saw an imporvement, no backfiring and less bucking, but still surging in 4th or 5th while cruising. I'm gonna try it out this week and see if my gas mileage is affected...

xsboost90

do you have a recirc valve or a BOV? Are you sure its working properly?

35thSLP

I have Russell's chips and they run perfectly. None of the symptoms you are seeing. Idle is even normal. Sounds like something else is going on. Maybe a FPR problem or vacuum issue perhaps? My experience has been plug-n-play for the chips. I'd give Russell a call...

BlacknRedGT

I did blow a head gasket with the chips at 15 psi but I'm not sure quite yet if it was because of the chips. I'm installing a wideband a/f gauge to see if this was the case.

Jeremy Himsel

Under no circumstancess should you just live with it. Double check your mechnical sources and if the problem still is still there go to the chip. I had similar issues with 3 sets of Guru chips years ago. I finally got fed up and put in a set of Vitesse and the problems went away.

One of the hardest things for a chip tuner to do is remap a proper chip when there are other mechinical/electrical going on. I'd start by swapping the stock chip back in and go from there.

chrly924s

Thanks. I am going to recheck my vacuum lines. I didn't change anything when I swapped the chips. I haven't had time to ask Russell, and I know he would help out, but since so many people run them here, I just thought I would go for some feedback. I have an exhaust leak at my WG, on the inlet side that I am trying to fix. It leaks bad between the flange and the pipe when it is tightned down, but it will not let liquid thru when it is out of the car. I doubt this is causing my problem, but it could account for some of my trailing throttle back firing.

xsboost90

ive done a few runs w/ my car and the new chips- a/f looks about perfect all the way through besides alittle rich for a split second when i lift but we are working on that. Ive even turned boost up to 18 psi and did a quick run and a/f stayed within acceptable range.

89951DREAMER

I had the same problem with the Max951 chips. It was most noticable on the track when "lifting" the throttle in 3rd gear at high rpm into a gentle sweeper. I have changed to the Vitesse stg III and the problem is eliminated. I can't completely blame the Max chip, however, because I had a problem with the throttle position sensor. There was a flat spot in the tps, and I think that this compounded the problem. I still have the bad tps on the car, but the hickup is gone. Anyway, you should check your tps. Use a scope and look for dropouts in the signal. That will tell you if there is a flat spot.

Ian