j.kenzie@sbcglobal.net

Hi.
Just for fun I checked compression:
1: 145
2: 150
3: 140
4: 130
5: 130
6: 130
7: 125
8: 125

Not great, but not disastrous.
I am getting an unstable warmup idle, which is new.
I also changed the throttle cable which I saw had a cracked sheath.
I'll play around with it a little, but I'm running AFR of 12.5/14.5 (DS/PS) for now at idle.
Thanks for all the help,
Dave

hacker-pschorr

Have we checked cam timing?

j.kenzie@sbcglobal.net

Not for a while. Could be a PITA with the SC. I'll look tomorrow.
Thanks,
Dave

j.kenzie@sbcglobal.net

I looked. Checking cam timing will be a royal PITA. I need to pull the radiator to turn the crank, unless I can use a strap wrench on the crank pulley,(maybe if I pull the spark plugs, I can turn the crank from the SC pulley). Removing the TB covers will be a challenge, but just R & R of stuff in the way. Not sure I have the stomach for it right now. I'll think about it. TB was done 2 years before the SC and checked at least twice during that time. It's been 4 years now, so I guess things could have happened. I may talk to Carl, and see if he has any suggestions.
Thanks again,
Dave

Mrmerlin

seperate the 14 pin connector ,
touch pin 14 to the hot post this will run the starter.

google 14 pin connector 928.
its the pin furthest from the end that the wires enter and holds the thick yellow wire.

j.kenzie@sbcglobal.net

Great idea, Stan. Do my numbers suggest a cam timing problem to you also?
Thanks,
Dave

j.kenzie@sbcglobal.net

Cam timing perfect.
Was eventually able to bump the starter to TDC then cam marks were right on there reference pointers. I am getting better at changing spark plugs, and the Porsche spark plug tool is unbeatable.
I'm going to double check ignition timing too while I'm looking.
Thanks again to all,
Dave

j.kenzie@sbcglobal.net

Timing set to 8* at idle; 23* at 3K RPM, with vacuum advance disconnected.
Car runs best on closed loop idle AFR 13.5 with simulated NB signal from the WB O2 sensor. It goes way rich (AFR=10) and stumbles at heavy throttle under load, if I run open loop with AFR 12.5 at idle.
All in all, the car runs about the same as before. Generally strong, has a flattish spot around 2.5K RPM but pulls through it and is good at high RPM's.
I guess this is what I've got for now.
Thanks again,
Dave

j.kenzie@sbcglobal.net

I went for a test drive this evening. Car started quickly and went into a rapidly pulsing high to low idle. It evened out in a few minutes and settled to a steady 800 RPM idle. Drove about a mile, with so so running. Car died on me just outside my garage and would not restart. I got help to push it inside. Smells strongly of gas. Spark verified with timing light. Temp 2 sensor 472 Ohms. I think it's flooded.
Prior to no start, car was running just OK.. It would go very rich at WOT, but accelerated nicely at part throttle with AFR's in 12-13. Idle AFR was 14.5.

Reviewing my recent activities on my 4 rich/4 lean thread I have:
Found and fixed vacuum leak at AFM-TB joint due to broken TB studs.
Had fuel injectors serviced and replaced fuel hoses, FPR's and FD, fuel pump and fuel filter.
Returned PCV gases to manifold, rather than vent to atmosphere.
Changed timing to factory specs, I think.
Changed throttle cable due to broken sheath. Adjusted idle position switch.
As far as i know, except for above, I returned vehicle to otherwise previous condition.

Not sure where to go next. Not sure why it wants to run so rich. I will put my fuel pressure gauge back on tomorrow to check. I might have moved the setting on the RRFPR when I checked it for tightness.

Thanks,
Dave

j.kenzie@sbcglobal.net

Better.
I got it started by disconnecting the cold start injector, and pumping the gas pedal. The Rising rate fuel pressure regulator was adjusted very high(90 PSI @ 0 vacuum/boost). Since I fixed that leak at the AFM that may have changed the manifold pressure signal to the RRFPR. Anyway, with no load it's much more stable both on and off idle. It restarts easily and has a non-pulsating idle. I'm going to wait until tomorrow to road test, and test cold start.
Thanks for commiserating,
Dave

j.kenzie@sbcglobal.net

Doing pretty well.
In terms of fuel tuning on my L-jet car there are about 4 settings to tweak:
Idle speed ( set to 900 RPM)
AFM bypass mixture screw adjusts idle mixture (set 2 turns out)
RRFPR 0 vacuum fuel pressure (set to 50PSI)
RRFPR damper screw (set to open 1 turn)
These settings control AFR's throughout a range of throttle and engine loads. I played with one variable at a time trying to avoid lean spots and rich spots. I am still getting AFR of 11 at WOT, but my unmeasured PS cylinders may be seeing AFR of 13, so that may be about right. I have a slight flat spot about 1500RPM part throttle, but I can't seem to eliminate that without going way rich throughout the RPM range.
I will tweak a little more, but without a dyno, I am making changes on the street and judging performance along with watching AFR's.
Have a good weekend and a happy Fathers' Day,
Dave

j.kenzie@sbcglobal.net

Hi guys,
I had an idea for my rich/lean V-8. Since on the L-jet, there is a fuel pressure regulator for each bank of cylinders, could I somehow increase the pressure on my lean side? Maybe make one of the FPR's adjustable?
I don't really know exactly why I have this problem, but could this be a workaround?
Thanks,
Dave

j.kenzie@sbcglobal.net

To answer my own question, if you clamp the return line of either FRP the fuel pressure should not rise by more than 0.05 bar (<1PSI). So they are redundant and without some replumbing the pressure will stay about the same throughout all the fuel rails.
Thanks anyway,
Dave

j.kenzie@sbcglobal.net

Hi guys,
I thought I'd post some follow-up.
I went back to open loop. That gives me an idle AFR of 12 on the left and 13.5 on the right. Under throttle they stay 12-13 L, and 13-14 R, under various throttle loads. I played around with timing, but ultimately left it at the low end of stock advance (thanks for the advice guys).
The car is running great, stays cool and has plenty of power. About the only negative is the rich idle, with its rich smell.
Thanks again for all the help,
Dave

j.kenzie@sbcglobal.net

Hi guys,,
Sorry to resurrect this old thread, but it's toward Winter, and it still bothers me.
My problem was and is that the PS cylinder bank runs lean, about AFR 14, when I have the DS running AFR 12.5. I had my injectors cleaned and matched, and my FPR's are new, Plugs fine.
Hacker asked if my cam timing was OK, and I eventually answered YES.
Well I double checked today and it looks like my DS cam is just a little less than one tooth behind. Would this be enough to make the DS run relatively rich?
Is it enough to redo the timing belt? I know perfect is desired, but should I tear down the front of the engine, including the supercharger, for one tooth?
Thanks for all your patience.
Dave