SES light

[Jim Nolan]

I had my '92 modded a couple of years ago by a known tuner but I wasn't real happy with some of the results, (rough idle and backfire) so I had Haibeck retune an extra e-prom I had for me to see if I got different results. The mods were;

Ported heads, injector housings and plenum
SW headers no cats
Corsa exaust
3:92 gears
Reset cams
and I added
K& N filter
Relocated temp sensor

The Idle is smooth and the backfire is gone but with a hard shift above 6k I get a momentary SES light. Using Gordan's kit I could not find any stored codes, Marc set fuel scheduling for 410/420hp. Any ideas?

[Kevin]

vac leak

[tomtom72]

It could be you are running out of vacuum and it's setting a DTC 61 intermittently ?? You said hard run to 6+k rpms, and that would be where the manifold vac drops almost to zero and in theory our vacuum pump is supposed to pick up any shortage of vacuum in the system to keep the 2* actuators pulling on the 2* linkage.


Not to be a wise guy, did you use the Gordon jumper for the CCM? I think that's where the history codes and intermittent codes are stored....I think!


Tom

[Jim Nolan]

I tried them all, ECM, CCM etc; nothing. If it is a vacuum leak I wonder why it didn't show up with the other e-prom? But, I'll check all the vacuum lines.

[GOLDCYLON]

My guess would be a lazy secondary vaccumm actuator under the plenum. One of the pair

[XfireZ51]

Originally Posted by Jim Nolan

I tried them all, ECM, CCM etc; nothing. If it is a vacuum leak I wonder why it didn't show up with the other e-prom? But, I'll check all the vacuum lines.

Could be running a bit lean at top end depending on what Marc did with fuel. See if you can datalog while you do a run.

[Paul Workman]

Originally Posted by XfireZ51

Could be running a bit lean at top end depending on what Marc did with fuel. See if you can datalog while you do a run.

Ummm-yeah. Had that thought too when I read 410-420. Mine was initially set by Marc for ≈ 450 hp before I ported the heads. I had no SES. Logically speaking, it would seem (to me too) that one possiblilty might be a lean condition???

Dom, we're starting to think alike...AND DON'T THINK I'M NOT WORRIED!!

p.

[XfireZ51]

Originally Posted by Paul Workman

Ummm-yeah. Had that thought too when I read 410-420. Mine was initially set by Marc for ≈ 450 hp before I ported the heads. I had no SES. Logically speaking, it would seem (to me too) that one possiblilty might be a lean condition???

Dom, we're starting to think alike...AND DON'T THINK I'M NOT WORRIED!!

p.

Well if the SES light comes on then then goes off during hard acceleration, that usually indicates an intermittent lean condition. Now WHY its lean is a matter for discovery. I had that happen when I ported my top end. Turned out to be fuel pump.