I have an 87 l98 4+3.



The car was running extremely slugglish the other day, so I went through looking for a cause.


I checked the timing with a timing light. I unhooked the wire by the brake booster, which cause the car to idle different (as told to do in the shop manual)

I found that it was 4 teeth below the line. I loosened the distributor and set it in line. Tightened it, took it for a ride, and it ran 100x better. Came home and realized i never plugged that wire back in. Took it back out and it seemed like it was advanced way too much. It was bucking and having a hard time driving in the 10-30mph range.

If i drive with it unplugged now, it runs, but hesitates and loses alot of power.

The 'stock' timing advance for it is 3 degrees i believe.

What do I need to do to get this thing back to its best timing.

Be somewhat detailed please so I can get this right!

Thanks in advance

 

The stock timing if 6 degrees BTDC. BTDC is located counterclockwise from the zero mark on the timing tab. Clean off the timing tabe and locate the 6 degree make and then set your timing.

 

Let me try to Dick and Jane at least part of this.Your Damper has a line (grove) which is a reference mark. Timing tab has teeth on which there are stamped numbers. One of these numbers is 0. When the line on the damper ig aligned with the 0 number number one piston is at Top Dead Center (TDC). Going counter clockwise the timing tab is marked in 2 degree increments.With the EST wire disconnected,as you have done,set the timing at 6 degrees Before Top Dead Center(BTDC). You may have to clean and mark with white paint,or whatever, both the damper and the timing tab so the correct marks can be clearly seen when the timing light flashes. Hope I did not insult either your intelligence or mechanical ability with this.

 

nope, thats what i needed to know.

thanks

ill see how it works

 

just set it right on, plugged back in, runs much better! thanks!

still a little lag. when you hit the gas hard it accelerates , but after about a second or two it really takes off. i don't think that has anything to wwith the timing though, right?

 

If your car runs better with the EST (timing wire) disconnected, then you need to take a closer look at your harmonic balancer to see if it is slipping. The balancer is the thing with the mark on it that you use to set the engine timing. If you don't know how old the balancer is, it may have begun to slip on you.

The balancer is a center hub, with an outer ring (which has the timing mark cut into it), and a thick "rubber band" like strip in the middle. Over time, the glue that holds the inner and outer sections breaks down and the outer ring begins to move or "slip". This means that you can no longer set your ignition timing correctly because while the indicator says it is at 6 degrees, in reality it is not.

The solution is a cheap fix. A new balancer is around $50, and you can use the "loan-a-tool" program at any of the major auto parts stores for the puller and installer. It took me about 3 hours to do the job. Automatics take longer than manuals, because you have to get under an automatic and put a wrench on one of the flexplate bolts to keep the engine from turning when you remove the crank bolt. In manual cars, you can just put the car in gear and the engine won't turn (I would chock the wheels as a precaution, though).

I took some photos when I replaced my balancer. You can see them here:

http://members.***.net/effergyvette/..._balancer.html

 

may disconnect battery and reset computer then retime.

 

thanks, ill look into that. its running really good now but its still worth a check. im throwing on a fuel filter in the morning and see how she goes

 

A fuel filter could be the cause of your laggy throttle response.

 

Its a thought if he had been messing with the fuel system. But, he was not. The OP was changing ignition timing and if he was to set the base up to 8-9 BTDC he'll probably find the the throttle response is better.

But, Hey! What do I know?

 

i replaced the fuel filter this morning, the throttle response improved about 50%, but theres still a bit of lag.

you think i should bump the timing up 2 degrees or so? I always run sunoco ultra 93 octane it

 

Probably wouldn't hurt to try.

 

Bumping the timing up a few degrees at a time will not hurt anything. You'll hear the knocking if your up too high. And the ECM will pull back the timing to compensate and prevent damage. Just find the spot where the engine runs its best, doesn't ping and temps are normal.