Calderone

I don't remember which was the member that i was sharing this experience some months ago,before the tranny rebuild it happened and now its happening again,but not always.-

Its a strange symptom...
The car acts like its towing something,i press the gas pedal and its like sleeping,it sounds accelerating,but in a low tone,with a nice boomboomboomboomboom i have to floor it a bit (not complete floor) and the car wakes up and accelerates,normally,but if i put 1/4 throttle,it acts dormant,then goes away.-

It does not happen everyday,its sometimes only.-
i was thinking ...and i came up with this :
- MAF ?
- Injectors ?
- o2 Sensor ?
- Transmission ? (i don't think this one,because its not a slip feel)
- Valves ....? today we adjusted the valves again and they are not noisy anymore,for those who remember my thread of a "bird" that sounds like a pulley,it was loose valves.-

I Received a PM from a member which i don't remember,
rodj told me something bout "drawing in "unmetered" air to the engine.ECM will see engine as running lean and try to richen it up .Need to hook up the hose from cover to TB port on RHS"

Any of you has similar problem ?
what's the cure ?
thanks !

Master__Shake_

No power under accel, huh? Sounds like plugged cats to me. What is your exhaust layout? Could also be running bad gas, if your tank was near 1/4 it might've sucked up some chunks that have been sitting at the bottom.

It used to happen to me frequently when I had the TPI, not once since the swap. Sometimes computers can be more of a PITA than they're worth.

Calderone

Hi MS !!!!
i have no cats,and my exhaust is clean.-
Yes bad gas could be,i hate when that happens.-
i think its computer related,maybe some bad sensor reading
any more experiences ?


ps : how's your carb setup ?
did you sell the intake/runner thing ?
thanks ! Nice to read you !

mr.beachcomber

If you have the 700R4 transmission, the symptoms sound like the torque converter isn't unlocking when your tranny downshifts into second gear for passing. Alternately, the converter unlocks, but the tranny doesn't downshift from third to second gear for passing. Either of these scenarios would make your Vette sluggish during acceleration. Hope this helps.

dan_t

no ecu codes? it almost sounds as if its setting an ESC or Knock Sensor error code, in this case it pulls something like 20degrees out of the timing map. More noise, but less work done...

CorvetteMike2024

Sounds like timing issues possibly.

PAINTER MAN

Since you just worked on the transmission, that is were I would be looking.

Calderone

its strange because its not when the tranny has to downshift,its the opposite,it happens when the tranny upshifts,its feels like it goes from 1st to overdrive or something and it gets real heavy.
This happened way before i worked on the trans,its too heavy to be the transmission
the transmission has not a super heavy gear....i have to check the codes since i delete them every day cause i have a master switch,i don't like my vette to sleep with the battery on,i disconnect battery every time that i park it.-

Calderone

The noise does not get louder,it sounds like its pulling a really heavy load,i've never experienced the ESC or Knock sensor error..so must be that maybe ....or maybe what rodj said before about unmetered air and getting rich,but no rich black smoke comes from the pipes at all like carbed cars.

dan_t

a car with retarted timing will sound laboured - not louder as such, but not happy...

Calderone

So..maybe the timing gets retarded because of the knock sensor ?
and the knock sensor is acting ......because ?????
thanks

dan_t

either way you shold have a "check engine" light come up on the dash - you need to check for saved codes, you will find out how with a search.

If your getting real knock the sensor will "hear" it and the timing will retart, if the knock sensor fails (or wiring) then the ECM will defult it to something like 20degrees retard.

Another thing to think about is the ESC wire that you unplug to check your timing - this does the same thing.

Calderone

Dan,yes there is a check engine light,it appears all the time,i haven't read the codes yet
but yes,i know how to read them,i will read them after a trip here and there.-

Does the ESC goes to the dist ? i think i know which one is it,the brown connector.

Im sure both wires are OK ,what you got me thinking now is that....since i put Hypereutectic flat tops,the compression raised i guess to 10.2,the chip is catching this
and worrying about it making it act funny,not sure anyway.

Maybe its time for a pcmforless tune.- ????

dan_t

have added you on MSN - will try and help

MK 82

If you have a recurring Check Engine light, you really should pull the code before you come asking for help.

Master__Shake_

I did sell the Hi-Flo Edelbrock setup, by the way. Sorry ya missed out on it. A guy from England snagged them up since parts are so expensive out that way. The carb is still running strong, even with the colder weather these days. Only a few weeks left until it's time to put it away.

On the topic, I still think it might be gas. The time mine had a bad 1/4 tank it misfired and ran sluggish for a good 5 miles before I put in a fresh tank with some fuel cleaner. Get the SES code out and if it isn't any sensors then I'd bet my money on it. It can't be the tranny since it happened before and after it was rebuilt, just less frequently. Good luck my friend.

cv67

Start from ground zero with codes. Ck F.P. too
When the trans was worked on was the TV cable reset properly?
Sounds like its upshifting into OD too soon and that will lug the motor down.

Calderone

Hi guys ! Yes it was reset properly,the same issue happened before i messed with the trans.- thanks cuisin !

Hey MS ! yes i missed on the intake and runners,it was an excellent deal,i spent the money on the trans.- Good to know the carb setup its cool !!!
hey ...." Only a few weeks left until it's time to put it away. "
put away what ?????? are you sellin your vette ???????????????
i will check for codes after the injectors mess
thanks a lot !!!

runner140*

Might want to start with a fuel pressure check, and check the fuel pump and change the fuel filter. (for starters)(check for code yet?)