Is my TIMING causing this??

[gottfuel]

ok i start it up and starts good then starts to idlemildly up and down,.(hi an low) not hard just smoothly. also when ive been driving and i come to a stop sign/light, i have to really stay on the brake cause it idel kinda high, now i notice if i shut it down and start it back up again it will idel normaly againg,.sometimes i get lucky and shell run real good , and then sometimes i have to shut down and restart,.,. anyone have any idea what going on? im thinking maby my timing chain is going bad? please help.....

btw its a 91 silverado 5.7 tbi stock with flowmaster

[1500chevy5.7l]

i have the exact same problem mine is fine in open loop but as soonas i hit closed loop it idels up and down from like 650-750-600-650 and so forth anoying but i cant figure it out either so if you fixc it let me know!!!please..

[89SilverBullet]

check to see if ur distribultor is loose... mine was.. and once it warmed up.. it ran like **** b/c the timeing was WAY retarded...

[1500chevy5.7l]

well i have tired a new msd disty from msd new wired from msd.ect you name it i proballt have tried it....nothing works...

[chevyz71man]

Check to see if the throttle shaft has play in it. Like up and down. Chances are the bushings are wore out and it is leaking air passed and the Iac valve is freaking.

[gottfuel]

OK i just finished pulling the codes and here is what i got....

code 22
code 32

i am going to be ref these codes to find out what they mean ... but as im doing so if anyones know right off the top of there head please tell me ..... also if you think my issues discused in my threads are related ...thanks in advance...

[HaulnA$$]

OK i just finished pulling the codes and here is what i got....

code 22
code 32

i am going to be ref these codes to find out what they mean ... but as im doing so if anyones know right off the top of there head please tell me ..... also if you think my issues discused in my threads are related ...thanks in advance...
Code 22 = TPS Low
Code 32 = EGR Fault

Both of these can cause the symptom you describe. Disconnect the negative battery cable for at least one minute then re-connect. Go for a drive and see if both codes come back. If so, replace the TPS and EGR valve. This should take care of it. I suspect the TPS code may be due to something else and that the EGR valve is the real problem. Be sure to chesc the EGR passages in the intake manifold. They are known to get clogged up. JMHO, HTH.

[MStefak]

With a very open exhaust if your running a sinlge wire 02 sensor this will cause the same problems.

MY .02 cents.
MStefak