Author Topic: 944 turbo - exhaust red hot when idling.  (Read 9404 times)

Offline TorSEilertsen

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944 turbo - exhaust red hot when idling.
« on: August 01, 2018, 12:26:26 am »
Hi all!
Working on my 944T VEMS project. (no, not the Peep PnP)
It now idles just fine at 800-1000 rpm, checked ign timing with ing strobe light. Fires on the mark.
When car is warm it runs on lambda target. Brand new Bosh LSU 4.9 sensor, calibrated in free air.
I have no idle control mechanism, only throttle body, and it idles in "a vacuum"
EGT sensor, runs at about 5-600'C
Bandaged headers, all the way to the (bigger)turbo, turbo in "bandage daiper"  I can barely see the red metal in the cyl 2-3 exhaust joint
But  the exhaust headers gets red hot! Registered some back firing as well (pop in the inlet manifold, when throttling)
Oil also smells of gasoline, pretty bad..
Could it be:
a) Normal. Steel will glow at 600'C? Just do a oil change.
b) Back pressure. Clogging in exhaust / turbo not spooling correctly?
c) Running to rich - sensor fail/bad calibration?
d) Running to lean, maybe caused by not getting air/ICV delete?
d) Injector setup fail - burning excess fuel in the exhaust?
e) some thing else i did not think about..

Anyone with ideas?

Offline jrussell

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Re: 944 turbo - exhaust red hot when idling.
« Reply #1 on: August 01, 2018, 04:52:36 pm »
Either B or your timing advance would be my guess. Did you zero (or set to the same degree as the mark) in the Ignition Lock screen under tools when you strobed the timing?
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1988 RX7 Turbo

Offline TorSEilertsen

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Re: 944 turbo - exhaust red hot when idling.
« Reply #2 on: August 01, 2018, 10:22:33 pm »
Hi Jussell.

All i did was to stobe the cam- and krank tooth wheel when idling, from coil/cable cyl.1. Should i set something in vemstune as well?
Both flashing more or less right on the mark. 0' (-+5' ish)?
It does not correlate well with the 8 degree adv it shuld have according to table/gauge?
Something is strange..
I thought / hoped i got the trigger setup  correct by now, but maybe not..
One thing i find strange, is that no one can give a correct trigger setup for 944 turbo, with stock trigger and tooth wheel. Must be hundreds of 944T's with vems out there by now.

http://www.vems.hu/wiki/index.php?page=MembersPage%2FTorSEilertsen

Offline TorSEilertsen

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Re: 944 turbo - exhaust red hot when idling.
« Reply #3 on: August 01, 2018, 11:33:48 pm »
Could it be my knock sensor, retarding ign to much?

Offline jrussell

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Re: 944 turbo - exhaust red hot when idling.
« Reply #4 on: August 08, 2018, 08:29:01 pm »
Get the engine warmed up to around 80C coolant temp. Anywhere close is fine. Go to the Tools Menu and Use the Ignition Lock. Lock the ignition to 0.25 (1/4 degree) if your timing mark is at 0. If the mark is at a different place (5 or 10deg are common, but all cars can be different and I don't know the 944), then set the ignition lock to what the physical mark is on your engine, and adjust the
TDC after Trigger value in the primary trigger settings until the mark is perfect.

I don't see any knock adjust in the log you attached to the SharingCenter.
VEMS USA - Located in beautiful Burlington, Vermont
1988 RX7 Turbo