93SSEIsc 73,000 MI GREEN LANTAN AND I'M LOVING IT

PROBLEM: ROUGH IDLE ON START UP SOMETIME THAT COME WITH A CHECK ENGINE LIGHT. CODE: QUAD DRIVE B FAULT 56, STEP ON GAS CHECK ENGINE LGHT GOES OUT AND ENGINE RUN NORMAL.

ALSO,ENGINE STUMBLE ON ACCELERATION UP HILLS.
TUNE WAS DONE SPARK PLUG, WIRES,PCV,AIR AND FUEL FILTER WAS CHANGED
PROBLEM THE SAME. BOOST SEEN NORMAL , I CLEANED IAC, AND IT WAS DIRTY. OPEN TO ANY COMMENT, I WANT TO KEEP THIS CAR TROUBLE FREE.

I'd be checking out the EGR system first then go to the TB area like MAF and IAC, etc.

Quad B has to do with solenoids for the EGR, TCC and Boost.

It may also be a bad PCM.

I am leaning toward emmissions problems though if it works based on heat.




also.

I agree....I think it'* more of an EGR problem, especially since you touch the gas and it goes away....maybe check your O2 also?

EGR seem fine,not sticking or busted. i cleaned iac, yes it was dirty.i will changed o2 sensor and the intake gasket this weekend.
notice: on locate street, my check engine light would come off and on every few second check and code 56. but on the highway at 65-70mph not once is get a check engine light. where is my boost or tcc sol. is located, how would i know if they no good. it still stumble on acelecation on hill.

okay, that'* freakin hillarious.

My vote is for the EGR valve.... had the same symptoms ... changed it .... SES gone and running fine.

salmanman

i agree also

hmmm sounds like the same problem i am having 2

sorry for late respone. i changed the EGR valve $213.00. and 02 and the problem the same. I also try the tcc test, at 55-60mph, i touch the brake while holding that speed and the rpm jump from 2000 to 2300, because it does chug at 1500rpm at times(when cold). I unplug the boost sol. and nothing change. should i unplug the tcc to check or replace the pcm. how could code 56 b fault can make my car hestitate when you first start the car in park sometime, and come on when up to temp. as soon you release the gas pedal it come on, and goes a way when i apply gas. what is the chances my car is the only one to to have this B FAULT that act this way. Can TPS set this off :(

no more b fault, i replaced my boost sol. which was the cause of my ses light to come on when i release the gas pedal. founded an old post here that help me out, never thought it can be the boost sol. i figure i had boost if the gauge respone on gas. http://www.bonnevilleclub.com/forum/...ic.php?p=19517.
thank for those whose give me there input, which lead my to the right direction.
bonneville club is cool with me