How to hold 3000 RPM to check timing?
08-23-2013, 02:11 AM
#1
Rennlist Member
Thread Starter
How to hold 3000 RPM to check timing?
Hi,
I want to check my timing. I can check it at idle, but how do I hold 3000 RPM while working under the hood? My 84 L-jet does not seem to have an accessible throttle control. Any tricks? I know it's probably a dumb question, but I don't have anyone to help me by standing on the gas pedal.
Thanks,
Dave
I want to check my timing. I can check it at idle, but how do I hold 3000 RPM while working under the hood? My 84 L-jet does not seem to have an accessible throttle control. Any tricks? I know it's probably a dumb question, but I don't have anyone to help me by standing on the gas pedal.
Thanks,
Dave
08-23-2013, 02:19 AM
#2
Administrator - "Tyson"
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This job requires the single most expensive addition you will ever add to your garage.
Mine is named: "Lorelei" and I paid extra for a German one
Mine is named: "Lorelei" and I paid extra for a German one
08-23-2013, 03:14 AM
#3
Former Sponsor
Buy a timing light that reads out rpms. Hold the throttle open until you get to 3,000 rpms. Switch to timing mode. Way close enough.
08-23-2013, 09:20 AM
#5
Rennlist Member
Thread Starter
The throttle on my car is down under the very hot spider and I don't se a way I can reach in there and hold it open, Greg. I cannot rely upon my wife to do this, so I may use one of those bar clamps set up to spread rather than clamp, and press between seat and gas pedal.
Thanks,
Dave
Thanks,
Dave
08-23-2013, 10:02 AM
#6
Drifting
08-23-2013, 10:25 AM
#7
Rennlist Member
Thread Starter
I really tried to reach it, but couldn't. Anyway my spreader clamp on the gas pedal worked fine. A 2 x 4 cut to length and wedged between the seat and gas pedal would also work, and you can use the electric seat fore and aft controls to adjust speed.
ANYWAY:
The reason I was checking timing:
I just finished TB/WP, green wire replacement, alternator replacement. In spite of checking my work many times before buttoning up, the car ran like crap when I first drove it. I had moved the distributor a little to get to the green wire screws, and marked the old position with a magic marker. I would say I was 1/8" off on the adjustment arc. When I set timing to factory specs, the car is like a ROCKET again. (I exaggerate, but it's fine again.) My point is, the timing is very, very sensitive, so be super careful if you move distributor. I didn't realize how much.
Good luck, and thanks for all the help,
Dave
ANYWAY:
The reason I was checking timing:
I just finished TB/WP, green wire replacement, alternator replacement. In spite of checking my work many times before buttoning up, the car ran like crap when I first drove it. I had moved the distributor a little to get to the green wire screws, and marked the old position with a magic marker. I would say I was 1/8" off on the adjustment arc. When I set timing to factory specs, the car is like a ROCKET again. (I exaggerate, but it's fine again.) My point is, the timing is very, very sensitive, so be super careful if you move distributor. I didn't realize how much.
Good luck, and thanks for all the help,
Dave
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08-23-2013, 10:32 AM
#8
Nordschleife Master
You solved it to your satisfaction. Congrats!
My approach is simple: reach under the spider and rev it up until the reading stabilizes. The 3000 RPM number is a point after which the mechanical advance is "all in." Earball 4000 RPM and it's fine. The spider is warm, or hot, but won't burn you.
My approach is simple: reach under the spider and rev it up until the reading stabilizes. The 3000 RPM number is a point after which the mechanical advance is "all in." Earball 4000 RPM and it's fine. The spider is warm, or hot, but won't burn you.
08-23-2013, 10:40 AM
#10
Drifting
and you can use the electric seat fore and aft controls to adjust speed.
very smart and great post Dave.
3000 rpm when standing over the motor is a real rush!
Glad to read you got her running well again, sounds like your 928 is fit as a fiddle.-Matt
very smart and great post Dave.
3000 rpm when standing over the motor is a real rush!
Glad to read you got her running well again, sounds like your 928 is fit as a fiddle.-Matt
08-23-2013, 10:55 AM
#11
Rennlist Member
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A few years ago, I found a leg from a camera tripod in a yard sale for twenty-five cents. It is small, light, and telescopes with lever locks. One end on the throttle pedal, other end on the seat back, adjust and lock. Very handy.
08-23-2013, 12:28 PM
#12
Rennlist Member
Thread Starter
I was thinking: Can I advance the timing 3-4 degrees at idle, and run premium gas, to improve performance? For my car the WSM says 4-8* BTC at idle with vacuum hose removed. This gives 20*BTC at 3000 RPM. If I set idle timing to 10* BTDC I assume the 3000 RPM will go to 24* or so. I would reset the idle speed to 650 RPM, and have a little more pep? Mileage would suffer a little, but my drives don't put on that many miles. Any thoughts?
Thanks,
Dave
Thanks,
Dave
08-23-2013, 12:36 PM
#13
Administrator - "Tyson"
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08-23-2013, 01:10 PM
#14
Drifting
I was thinking: Can I advance the timing 3-4 degrees at idle, and run premium gas, to improve performance? For my car the WSM says 4-8* BTC at idle with vacuum hose removed. This gives 20*BTC at 3000 RPM. If I set idle timing to 10* BTDC I assume the 3000 RPM will go to 24* or so. I would reset the idle speed to 650 RPM, and have a little more pep? Mileage would suffer a little, but my drives don't put on that many miles. Any thoughts?
Thanks,
Dave
Thanks,
Dave
08-23-2013, 01:21 PM
#15
Drifting