Car shudders under heavy load.. EGR related?

[AlcHEmiE]

You may or may not know, but i have been having some problems with my car at idle. With the help of some forum members, we have narrowed it down to the EGR valve. http://www.corvetteactioncenter.com/forums/showthread.php?p=410146 Thats the thread with the EGR discussion. But tonight i've noticed another problem. While on the highway, i was going about 45 MPH, and i went to pass another car. I floored it completly, it downshifted, but as it took off it seemed to shudder.. Like it didnt want to go. The headlights kept dimming and my battery light was flashing..

Could this also be related to the EGR, since i understand that the EGR valve is closed at idle and WOT, and at this time i was flooring it completly. I checked a few websites and i cant seem to find a EGR cheaper than $60.00. Autzone had one for $45, but when i tried to order it today (online and instore) it is out of stock, and they cant special order it. Is there a way to remove the EGR completly, or disable it some way, since it is causing me more problems than i care to deal with. Passing emmisions is no problem.

Thanks again.. This seems to be the only part holding me back from fully enjoying my new vette

 

[jmccloud]

shudder

Your shudder sounds like you may have a loose battery connection, or bad battery. My '95 reacted similarly, but milder (Sys light blinked with rare misfire), when I got it. Turned out the battery was original. Replaceing it fixed the problem.
When we put a 'modern' engine in my son's '67 Camaro we disabled the EGR by cutting a piece of aluminum flashing in the shape of the EGR face and drilled two holes in the flashing for the mounting bolts. Then slipped the flashing in under the EGR so the gas passages were 'blinded'. Our attempts to just leave the vacuum control hose connected to nothing didn't work. The valve would 'leak' and cause idle problems.
Good luck enjoying your new Corvette.

 

[AlcHEmiE]

Battery was replaced June 2003. I check the connections and they seem fine.. But my voltometer is reading a high charge of 17 amps. Is that normal?

 

[Moonunit 451]

If emmisions isn't a problem for ya, you can remove all the pollution crap from the AIR pump to the EGR and a bunch of other crap that is unneccesary. It really cleans up the engine compartment and makes the car easier to work on!

 

[AlcHEmiE]

Is it a possibilty of bad injectors maybe? Or even poor Plugs/Wires/Cap? I'm open to any suggestion right now, because i cant really step on the gas without this shudder.. Its bothering me alot!!

 

[LIBERTY]

Don't change the EGR valve just yet! The valve can be checked by doing the following....
1- If you suspect it is partially stuck open: start the engine cold and touch the EGR tube leading to the intake manifold. If it gets really hot, the EGR is leaking.

2- If you suspect the EGR valve is not working: run the engine at idle, use a vacuum pump or a steady vacuum source from the engine and apply it to the EGR valve. If the EGR valve is working properly (this will also check the EGR tubing and ports) the engine should begin to stumble and sputter. If no response, either the EGR valve is in-op or the EGR ports are plugged.

Having said all that, the EGR is not the root of your problem...

Here are some things to check:

-Is your car auto or standard? check trans fluid level and condition
-check fuel pressure, you may have a weak fuel pump or restricted/dirty fuel filter
-check ignition output (you may need to visit a shop) you may have a weak igniton coil
-check battery terminal connections, battery condiition and all ground connections
-with a fully charged battery, try disabling the alternator (remove the small two or thre wire connector) and go for a drive under hard acceleration. You may have an alternator that is causing feedback.

There's some things to look at... post your results

 

[vette-dude]

I don't know for sure but my 85 Monte Carlo SS did this and it was the lock up torque convertor. I tried changing the electrical switch inside the trans and it helped for a while but eventually had to put in a new convertor. Wonder if perhaps you could have disconnected the harness wire (or it is shorting out)going into the trans to the switch. Just a thought. Maybe that's why the lights dim and all. Good luck just trying to give you something else to consider.


Randy

 

[AlcHEmiE]

Went to Autzone today and had my alternator tested.. It didnt work. So i bought a new one, threw it on this morning and wow... When i got the car, i didnt know the alternator was bad. But i would come to a complete stop and floor it, and it wouldent spin tires at all. I tried that again After the alternator swap and let me tell you.. I think i spun for a good 6-7 seconds before i let off the gas and it snapped my neck.. Thanks for all your help!

 

[Moonunit 451]

Right on! Happy motoring