Hi,

Has anyone experienced a consistent power drop in especially 3rd and 4th gear? On the dyno it shows the power dropping to zero and spiking right back up over the interval of approximately 100 rpm. When driving the car there is a noticeable hesitation. The car has stock computer, intake, downpipe, cat back, stock mid section. The car does have a boost gauge however where the brake up is occuring, the gauge is only showing 10 lbs. I know this sounds like overboost fuel cut, but at only 10 lbs I am confused. I am going to try swapping a spare ecu, as well as a pettit unlimited and see if that fixes the problem. Any other ideas?

Thanks,

Andrew Wojteczko
andrew@voytechco.com

 

I'm surprised that you are not running a modified ecu already. What boost gauge are you using? If its the autometer on then they can be very inaccurate up to 1 psi off. It sounds like you are hitting fuel cut. Get a boost controller asap to keep the boost to 10 psi or there will be a good chance that you may pop your motor. Get a modified ecu asap as well to ensure that you will be safe.

R.K.

 

This one isn't mine, it's in for repair, I'm running a profec B already, and I'm installing one in this one as well, i believe the boost gauge is the one pettit sells, I think it may be the culprit as well.

 

the strange thing is, is when this gentlemen spoke with cam at pettit, he told him he didn't need an upgraded ECU.

 

i remember going down to Kdr a while ago, and somebody came down with his rx7 and was telling dave how the car didnt feel like it had any power after around 5 grand. They did a compression test and turns out that he had a chipped apex seal in the front rotor and his rear rotor was pretty much shot. I hope this isnt the problem, but it is very well possible. Check the compression asap. he may need more then an ecu.
adam

 

power is fine, it is definitely a fuel or ignition problem, the power is intermittent yet still strong, the car dynod at 270 whp

 

tca might be having problems, is your boost falling off?

what does your a/f ratio look like during the power drop off?

 

I had almost the same problem when I dynoed my car. Horse power drop as low as 50 when I hit 6,500 rpm, and then went all the way back up. Reason for that is that my a/f was so rich that it fell off the graph.. I know I have some kind of problem with the car, but never figure out what was.

 

you dont need upgraded ecu with stock cat. the car is most likly getting rich, but i never heard of this with stock ecu and cat. are you sure you dont have a gutted cat?
2 things you can do
1 take the cat off check it out (make sure ap is hooked up)
2 just upgrade ecu and see if anything changes.

good luck
geoff

 

if i had to guess, coil pack or secondary injector ground?