IDLES GOOD NOT TIMEING ADVANCE

2000 GMC Jimmy

Tiny

onewolf1952

May, 24, 2012 AT 11:35 PM

At idle timing is 30.5 TPS is at 3.1%. Smooth idle no miss fires, Increase throttle timing goes all over TPS at 11% timing is 30, 29, 28.5, 28, 27.5, At TPS The high TPS goes the lower timing drops at 100% TPS goes to 12 on down to -1.5then hangs around 6 to 2 deg.

Cad is clear, no vacuum leaks, MAF, new, ICM new, cap and rotor new, wires new, crank position senor new, computer new.

I am at a loss.

FOUND 330 RELATED QUESTIONS

5 Answers

Tiny

ASEMaster6371

May, 25, 2012 AT 12:32 AM

Wow, lots of new parts. Did you have a shop check this for you?

A big issue with the distributors is the lower gear wears out and has all kinds of slop thus changing the cam retard. You should have this checked.

Roy

Tiny

onewolf1952

May, 25, 2012 AT 1:04 AM

Thanks,
I ve had nothing but trouble from this truck so yeah replaced a lot of parts. Took it to dealership one time they said fuel pump bad but wires were cut from the gas tank band from a previous change, it was running great then slowly this problem came about over a period of a week. Some one said in is the knock senor but I really need a solution so I can trade it in for something to get me going down the road.

Tiny

ASEMaster6371

May, 25, 2012 AT 1:11 AM

The knock sensor will retard the timing in 4 degree incriments for a total of 4 times. If you disconnect it, it should remian stable. If not then it is something else.

Roy

Tiny

onewolf1952

May, 25, 2012 AT 1:19 AM

Ok I got to find it lol I understand it is a pain to get to. A distributor problem wearing is a great way to go, it came on over time and wear is consistent with your solution.

Tiny

ASEMaster6371

May, 25, 2012 AT 1:28 AM

Good luck

Roy

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