Bumped Timing = Idle Surge?

[SeventyMach1]

Well my car has had a perfectly steady idle at around 7-800 RPMs .... but in the past few months it has been running really crappy. So I broke out a timing light to check timing. It was at 0*!!! So I finally got the base timing set at 12* BTDC (without ping).

Now, the idle is surging between 800 and 1100 RPMs.


Any ideas?

Or better ..... why did this happen after I bumped the timing?

 

[HISSIN50]

Justin, why did the timing walk in the first place? Loose dizzy bolt or possibly slipped outer ring?

Did you notice the RPM's at idle go up much after advancing the timing 12*? You should have. It might simply taking a clean computer slate to see if it relearns how it should be. That's kinda weird.

Good luck and bump mang.

 

[SeventyMach1]

I will be honest .... I never checked the timing before (which is stupid on my part). When I purchased the car I took it over to a friend's house .... who proceeded to check the timing. He told me that it was at 10*.


Anyway ... I know the bolt didn't slip (it was a mofo to get loose, lol). I guess a slipped outer ring is possible ... or maybe the timing was NEVER set right.


Yes, the idle RPM did go up after advancing from 0-12* (which sounds normal). It just surges a little now. Thanks for the input. I think I'm gonna go reset the puter and see if that helps.

 

[94gts]

reset you idle too. theres a bunch of threads on here how to do it. Check the timing in a few days again. if its not at 12* then your balancer is probably shot.

 

[SeventyMach1]

Yeah, I know how to do the whole "reset idle routine". I was just hoping that I didn't have to go through all that crap (again) and maybe someone on here has experienced something similar. If the puter reset doesn't fix it .... then I guess I'll be doing the idle reset crap.

 

[gcomfx.com]

I put a new dizzy in my car and my idling issues STOPPED.... we changed the timing at the track a few times and I sprayed the car again. It ran great at first, then bumping the timing from 5* to 8* dumped a plug on the big end. Put new plugs in it, and the surging is back in full force. :x

 

[clang5oh]

i had some massive idling issues a while back, i cleaned the maf and it helped but didnt cure. then i went through the whole idle reset thing and it didnt get me anywhere. i then proceeded to check the timing it was at 30*. probably not, the balancer is shot. i set it to 10* and that didnt help (this is where i learned the balancer is shot, havent replaced yet). set it by ear and there is still a little lumpiness to it but not so bad. will get it dialed in right when i get time to buy and put balancer on.

 

[slocomo]

I put a new dizzy in my car and my idling issues STOPPED.... we changed the timing at the track a few times and I sprayed the car again. It ran great at first, then bumping the timing from 5* to 8* dumped a plug on the big end. Put new plugs in it, and the surging is back in full force. :x

What is a dizzy??

 

[gcomfx.com]

MSD Billet Distributor

 

[gcomfx.com]

i had some massive idling issues a while back, i cleaned the maf and it helped but didnt cure. then i went through the whole idle reset thing and it didnt get me anywhere. i then proceeded to check the timing it was at 30*. probably not, the balancer is shot. i set it to 10* and that didnt help (this is where i learned the balancer is shot, havent replaced yet). set it by ear and there is still a little lumpiness to it but not so bad. will get it dialed in right when i get time to buy and put balancer on.

Wish that was my problem... I already replaced my balancer with a SFI certified Pioneer.

 

[Therian]

I had this problem a couple summers ago. My RPMs would also 'bounce' a bit during acceleration though...turned out to be the ignition wires. I also cleaned the MAF/reset idle/cleared computer/cleaned TPS prior to replacing the wires and it helped a bit, but not enough