After seeing the inside of my head, it seems that I have a lean condition. What causes the Lean condition and how can I fix it?
1.8 bone stock with L-jet
You can make an adjustment at the airflow meter under the black cover where the swing arm contacts the carbon track.
I will see if I can locate the instructions I used. BTW I adjusted my air flap setting and it made some pretty impressive acceleration improvements.
Al
There is a mixture adjustment screw on the air flow meter. It works by opening or closing a bypass so more or less air flows past the flap in the air flow meter. It's enfluence is primarly at idle and low speed.
Before you pop the top off your air flow meter and start adjusting the wiper and/or spring make sure you don't have vacuum leaks and the engine is tuned properly (pts, plugs, valve adjustment, etc...).
It took me seveal days working on it to get the air flow meter adjusted back close to stock after someone had "fixed" on my VW bus.
Jim
Raise the fuel pressure ....
I would also assume that the 1.8L & "75-'76 2.0L engines were set up leaner for emissions purposes.
The bypass screw in the air box affects only the idle mixture. The fuel pressure isn't adjustable, except for the vacuum applied to the diaphragm under acceleration. It has a "rising rate" fuel pressure regulator. If there were air leaks, it wouldn't start. The big risk in resetting the spring tension in the airbox is getting it to be correct under a range of conditions. It can be done, but it actually requires a fixture and a way to read the injector opening in milliseconds to calibrate the opening vs. the enrichment. That's if you want to do it right. Running too rich has consequences for the driveability.
I'd look at the distributor, making sure the vacuum capsule works properly, and make sure the timing is correct USING THE PROPER TIMING PROCEDURE, which is far different than the procedure used on the D-jet cars.
The Cap'n
Before you start making adjustments, take off the rubber boot between the AFM and Throttle. Check it carfully for cracks. They hide and are hard to see. I found that this was my main source of Lean condition on my L-Jet. Small cracks that leaned it out but not large enough to cause too much trouble.
Since fuel pressure is also set by vacuum on the l-jet, adjusting the AFM is your best bet. It is super easy to do under the black cover.
thanks for the replies
I had a 912E come into the shop awhile back. The goal was to make it squeak past SMOG. After checking everything, swapping in some rebuilt components from Fuel Injection Corp, and replacing some seals it passed the test better than it had in 10 years. My point is that fixing the system is the best way to make it run the way it should. You should have to 'trick' it.
Good luck!
check all the vacuum lines, see if the ends are hard and cracking. get new ones or trim a bit off the ends if theres enough to do so. L-jet is so picky on vacuum leaks and will run like shit if you have i little leak and run poor if theres a tiny leak.
check dwell and timing too.
L-jet + lean == vacuum leak, almost always.
--DD
Come by and pick up my 1.8 with 80K. It's complete. Free for Joe S.
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