Timing question

[mikiedreb]

Has anybody hooked up a timing light and observed the timing curve as they reved their warm motor up? Did the timing initally retard, then advance as the RPMs increased?

Mike
92MTX

 

[sdpatt]

Apparently not.

 

[mikiedreb]

Wow,

Seems like a tough crowd out there..

Has anybody got a timing light and 5 minutes where they could check their timing curve...you know....start the engine, point the timing light at the crank damper and observe the timing marks? I'm curious if the CPU controlled timing on my 92 is the cause of my driveability issues. I'd like to compare your results with mine. Simply wing the throttle from an idle and tell me if your timing initially retards, then advances, or if it advances only.

Thanks

Mike
92MTX

 

[twr]

I have put a timing light on with the SPOUT connector disconnect - runs about 10 degrees and climbs slightly as throttle is opened.

 

[sdpatt]

The ignition timing is entirely controlled by the EEC. If you run the KOEO test, you will determine if the spark and fuel tables in the EEC are being read correctly. If you have an LPM, this test will show an error. I have never heard of this problem that you are decribing as being caused by the EEC.

Why don't you describe your "driveability issues" so that we can help diagnose them. You are predetermining the cause with your approach. That is limiting your responses.

 

[mikiedreb]

twrsho...thanks for your response. My timing is also 10BTDC and steadily rises with the SPOUT connector out. My interest lies in the timing with the SPOUT in and the EEC functioning.

I'm seeing 10 BTDC as steady idle, then a drop to 0 TDC followed by a rise as the throttle is winged.

I'm wondering if this is tied to a jerking, trailer-hitching motion I'm experiencing as I get off and then back onto the throttle while driving.

My car is stock with the exception on a K&N. I've replaced or cleaned all of the sensors, timing belt, cleaned and reseated all connectors, adjusted and ohmned the TPS, recent fuel pump. Motor mounts, subframe bushings and strut bushings also have been recently replaced. Plugs, wires, vacuum hoses...all replaced. Perfect idle, cooks at top end....but this herky-jerky business has got to go.

Mike
92MTX

 

[twr]

I don't know the strategies of the EEC, it may very well be that it's supposed to do that. Have you tried reseting the computer??

 

[mikiedreb]

twrsho,

I've reset the computer numerous times.

The reason for this post was to ask fellow members if they might check their timing with a light and relay their results with me to confirm whether or not I've got a unique situation...that is an initial 10 degree retard before the timing advances as the throttle is winged.

Mike

 

[twr]

mikiedreb:
twrsho,

I've reset the computer numerous times.

The reason for this post was to ask fellow members if they might check their timing with a light and relay their results with me to confirm whether or not I've got a unique situation...that is an initial 10 degree retard before the timing advances as the throttle is winged.

Mike

Unfortunatly my SHO is in more than a few pieces right now - I'm in the process of a 3.2L upgrade and quaife install.

 

[projectSHO89]

As per your your request, I hooked up my timing light and duplicated your test conditions.

On my 89, I observed a very slight creep of the timing from 10 DBTC to about 7-8 DBTC in the first 100 RPM, then it quickly began advancing the timing to about 12-18 DBTC depending on throttle position and quickness of throttle movement. I was not able to observe any timing closer than 5-6 DBTC.

Completely stock 89, well warmed up.

Steve

 

[mikiedreb]

Steve,

Thanks for taking the time. I appreciate it. thumb Looks like some amount of timing retard is to be expected initially. Just how much I guess is the question.

twrsho.....quit bragging wink !!!!

Mike

 

[twr]

mikiedreb:
twrsho.....quit bragging wink !!!!

Mike

Just wait until I get it back together thumb Then I'll be bragging..

On a side note - I have not driven my SHO for 3 weeks now and was going through withdrawels. I got the oppertunity to drive Panamapat's 445hp SHO for a couple of hours on Friday afternoon - took care of the shakes for a couple of more weeks (now that's bragging )

<small>[ April 10, 2003, 05:07 PM: Message edited by: twrsho ]</small>

 

[AutoSHO]

twrsho:

I got the oppertunity to drive Panamapat's 445hp SHO for a couple of hours on Friday afternoon - took care of the shakes for a couple of more weeks (now that's bragging )

squint

 

[twr]

AutoSHO:

twrsho:

I got the oppertunity to drive Panamapat's 445hp SHO for a couple of hours on Friday afternoon - took care of the shakes for a couple of more weeks (now that's bragging )

squint

Hey - if you would ever make it to a meeting you would atleast get the chance to ride in it

<small>[ April 10, 2003, 05:35 PM: Message edited by: twrsho ]</small>