Been breaking in the new 2.0L 9:1 GSR motor. But running into alot of bugs in the system before the turbo goes back on.

A month ago I noticed my car would misfire at idle and at low rpm, high load. This slowly got worse as time went on. As the car warmed up the idle would more and more erratic as it misfired more and eventually stall.

I replaced the spark plugs with NGK BKR6E's (NA plugs) gapped at .040" and also tried .030". New OEM plug wires. New OEM cap and rotor. Idle problem still existed however top end and cruising felt smoother. I was told that it might be the ignitor as that usually gets worse when it heats up. So I bought a new distributor from the Distributor King.

The new distributor totally fixed my idle and low end issues. And cruising feels much stronger. But it breaks up above 7500 rpm. Its not like a misfire as I dont hear the usual pops and back fires. It feels like surges in power almost like a soft ignition cut. If I keep on the throttle (wot) above 7500, it gets worse closer to 8000 rpm.

Im running AEM EMS. Its tuned and ran great before all these distributor problems. When I log this top end condition, AFR is steady at 13.0, ignition is steady at 31*, and there is no knock which would indicate that it isnt misfiring.

If I put my old stock distributor back on, the idle problems return of course, but top end is clean! I dont get it. Any ideas?

 

Hmm......Interesting, Have you tried adding some more fuel up top where it surges? I know you said the A/F is a steady 13.0, but at least then you could rule out fuel issues...

Timing belt slack causing erratic cam/ignition?

I dont really know,just throwing some things out there.Maybe someone else has had this problem before.

Do you have a stock ignition system?

 

Yeah stock ignition. Nothing fancy or complicated.
Actually one of the things I tried was disabling O2 feedback which did allow things to richen up about half a point with no change in performance.

Timing belt is perfect. I have adjustable cam gears and are set so crank and cams are TDC. They have no sliped or anything.

Like I said the weird thing is, when I put the stock distributor back on the top end issue is gone. It must have to do with the new distributor despite it fixing the low end problems. I wonder if anyone else has had issues with Distributor King dizzys?
Im think this is a mechanical issue, not a tuning issue.
Possible difference with the cam sensor?


Modified by Muckman at 11:32 PM 10/1/2004

 

Yeah it sounds like it is mechanical since everything else seems to be in check...
I just bought a distributor king dizzy and it works perfectly for me...

Can you look at your cam sensor signals with the EMS?
If so, try comparing the two distributors and see if they are giving off the same cam signal at the problem rpm's...

I guess you could also try and put the ignitor/module from the new dist. into your old housing and see what happens. I left the shield behind the rotor off on mine once and it caused me all kinds of problems...

Good luck and keep us informed!

 

I was able to do some more testing this weekend.

The old stock distributor with the new coil and ICM worked flawlessly.

But the new distributor king dizzy with the new coil and ICM suffered from severe timing errors as recorded by the AEM EMS. The common demoninator here must be the cam sensor/pickup.

Im sending this unit back for a new one. Hopefully that fixes it.

 

I got a chance to log this condition with the Distributor King dizzy. There is a ton of timing errors once the rpms climb above 7500. After that point there is also erratic cam and fuel tooth pickup readings from both sensors in the dizzy.

Here is the AEM log if anyone wants to see. Note, it doesnt have any of these errors using the stock dizzy. The tune is unchanged.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">I got a chance to log this condition with the Distributor King dizzy. There is a ton of timing errors once the rpms climb above 7500. After that point there is also erratic cam and fuel tooth pickup readings from both sensors in the dizzy.

Here is the AEM log if anyone wants to see. Note, it doesnt have any of these errors using the stock dizzy. The tune is unchanged.</TD></TR></TABLE>

Great info! Thanks!