help!!! a power loss

[91callaway]

when going up a incline (moderate) in 3rd gear and up i get a loss of power and check engine light comes on. feels very similar to our family car when i press overdrive button. does not matter if gas tank is low or full. it only will happen when revs drop to around 2,000. if revs 2300 or higher it never happens. i imediately stop car shut off engine and restart and all is normal. when its happening engine running poorly. not really sure if skipping but significant loss of power. ???????????????

 

[TAC]

There's many reasons to lose power. First and easiest to check is what's the code your getting? Do you know how to get the # from the computer? There was a post recently here about power loss on the Callaway due to the vacuum line coming off the microfueler under the dash.

 

[91callaway]

car fine 99% of time, so cant be that. only happens at low rpm up hill

 

[SurfnSun]

It doesn't happen when the engine is under load at low rpm on flat ground?

 

[91callaway]

it never has. but not sure ever under load on level ground.
callaway did some work with a gas pick up device (??) in gas tank. the said it was out of the pocket. they seemed sure it would resolve problem but it did not. before rebuild problem only occured if under 1/2 tank of gas. now doesnt matter if even full.
on a new subject, has anyone thought a of higher rear end gear.
when on ct highways (speed limit 65) most traffic moves along @ 70 to 75 mph. thats a bit to low for 6th gear and yet a bit to high for fifth gear. my 6th gear really is useless below 85mph. when cruising on a highway i like tach to read about 2200 to 2400.
when i first got my callaway i got to 138mph on a long straightaway on rt 395 (on way to casino) i meant to look at tach to see what rpm's were but it seems i forgot.

 

[TurboLuigi]

I have experienced similar problems when going to WOT on level ground with less than 1/2 a tank but then that is documented in the owners manual. Seems like the Fuel Pump (in the tank) starves for gas in an incline or when the gas sloshes in the tank from WOT.

I have not experienced this in a while, particularly since switching to Chevron gas (with Techron), and I don't know why. It used to do it before when I was using Shell and then Mobil gasoline though it doesn't make sense that it would be related to gas but then I am no expert, just relating my experiences.

Also, see an earlier post from Malc350 and his problems http://www.corvetteactioncenter.com/forums/showthread.php?s=&threadid=14882 but they don't sound like what you are experiencing.

Luigi
:cool

 

[91callaway]

very interesting. it should make no difference as u said but i do use mobil also. i did know that if u accelerate fast with less than half a tank full car will experience huge hesitation because gas in tank is pushed away from pick up by g forces.

 

[mangusta1969]

Watch for lean out detonation!

Lack of fuel (and lean out) is potentially a very serious problem under boost (acceleration) conditions. If I were you, I would pull the plugs and look for any signs of detonation right after a hesitation expisode. Any signs of melting or deformed electrodes or little spots on the ceramic insulators within the combustion chamber are what you are looking for (and hopefully do not find). If found, this really needs immediate correction.

It sounds as if this may be a common problem in the Callaways. That is a little scary to me, as lean conditions under boost will cause audible and inaudible detonation. This will break top compression rings, pistons, and rods if it is severe enough.

FWIW, my turbo BMW has two pumps. The primary pump is in the tank; there is a pretty good size booster pumper just after the fuel filter in the back of the car. It never has any hesitation problems under acceleration. Are there two pumps in the Corvette/Callaway setup? FWIW, the injection system for the Corvette is really an adaptation of the same Bosch Motronic injection system that is in my 1984 BMW. I hope they kept the two pump setup...

Is there a good technical description of exactly what Callaway did to turboize these cars?

good luck,

Steve

 

[90Callaway]

There is no point in guessing about this. If your SES (Service Engine Soon) light comes on your computer is logging error code(s). It could be your EGR, CCP (Carbon Canister Purge), IAC, O2 sensor, Cat, injector(s), something else or none of the above. Once you get the codes as Tim already suggested we can go from there.

It is not the fuel starvation problem due to low gas levels from what you described. Also, I don't recommend lugging the car below 2000rpms going up hills. Why tempt detonation? I only use 6th gear if I am on level ground and running over 65-70mph. If I go up a hill at anything less than 75-80 I generally take it down to 5th. It doesn't have much power at that low rpm under load anyway. I think lugging it is more of a strain than the few hundred extra revs it turns in 5th.

The most common cause of the Callaway TTs going lean is a problem with the microfueler. If the secondary injectors don't fire and you go into high boost you can very easily grenade the motor due to lean detonation. The Callaway uses an upgraded Bosch fuel pump but does not use a secondary pump. It provides plenty of fuel pressure for the application.