WIERD Ignition Timing Problem...

[rsmithdrift]

Ok, so I know how to advance/retard my timing. I been using it to adjust my cars powerband since 07. I would retard it when I would want to go drifting to a point I found and marked that gave me optimal mid range power and torque. And I'd advance it for getting more top end hp. (I have a good advanced, factory 20*, and a good retarded location all marked on the distributor)

Well, late in 07 my car started having problems so it's been slightly retarded for a while now.

I finally fixed the main problem with my car (damaged fuel injectors/FPR from diesel) and my car is running good again, it just has some hesitation around 2,000 to 3,500 rpm. It's running lean (I know this) so I thought retarding the timing a bit more might help it through that bad spot. IT MADE IT WORSE.

So, confused, I put it back to where it was. On a whim I just thought to advance it back to the factory location of 20* and it made it helped make the hesitation less noticable and made the power more prominent throughout the entire power band. So, even more confused, I set it to my advanced mark and sure enough, the hesitation is almost gone and my bottom end is back... WTF??? THAT"S BACKWARDS!!

I'm so confused by this because when the car is lean the fuel burns quicker and hotter, so you should need to retard the timing to get your bottom end back. AND, advancing the timing should make your car LOOSE power at bottom end and GAIN it on top end. But now it seems to have the complete opposite effect....

I don't understand what's going on here. Anybody got any clues??

[rsmithdrift]

Really.... Nobody has any ideas???

[rsmithdrift]

Well, I figured something out.... The timing IS infact, having the proper affect on the engine. HOWEVER, their is an added side effect on whatever is causing this low/mid range hesitation/power loss. For some crazed reason advancing the timing makes whatever's causing it to not cause it nearly as much, or it's just loosing so much bottom end torque that it's just that much less noticable, or a combination of both...

Anyways, from 4,000 rpm to redline the car is perfectly normal. Has all it's power, and timing affects that power as expected. BUT from 1,000 - 4,000 rpm the car has problems. The power comes and goes, and it cuts out fairly randomly as if it were running extremely lean. Because it is. It runs lean as hell in that rpm range for some unbeknownst reason....

Any thoughts??? Coments?? Ideas???

[boosted240sxnut]

im having a similar problem does urs run ok cold then start running like s*** dum question but did u check codes on the ecu for sensors

[Airmanspecial]

im have the same problem to....so far after replacing timing set, egr(stuck open..) im down to toubleshotting the MAF and crank postiotion sensor....i have to nurse the motor to 3k rpms and then she flys...so im guessing thats when its fully advanced....so either the maf is being intermitent, or the crank position sensor is. the timing isnt advancing as it should coming out of idle, and those are the only things i can think of atm..