Engine problem? Options

[Hine62]

Hey guys, just getting ready for the summer, but when I started up the 914 this weekend I noticed that it was running rough. (The engine has dual 34s carbs). I could hardly move the car in first or reverse (not even after warming up.) I did notice the driver’s side head is cooler than the passenger side. Here are the tests I've done:

Pulled plugs while running:
1. no change in engine sound 1 and 2 (drivers side)
2. noticeable change on 3 and 4 (passenger side)

Took a compression test: 120lbs on all cylinders. Of course, plugs did not look normal on the driver’s side, so something is up.

Getting spark on all cylinders.

Removed drivers side carb, found silicone covering hole in the accelerator circuit. Re-adjusted both carbs and linkage. Weird find but runs better.

Now the driver’s side still doesn't change the sound of the engine when pulling the plugs. It's like the cylinders are running better but not contributing as much at idle. The car is able to move better, almost normal now.

Just went out and checked temp on head and the driver’s side is still a lot cooler than the passenger side.

So the big question is what could be going on? Dropped value? Valve adjustment tighter on drivers side? Carb problem still? Replace the plugs? Leaking between head and cylinder? Time to upgrade carbs to dual 40s or 44s?

Any help would be appreciated...

[jcd914]

This sounds like a carb problem.
You have good compression and spark on all 4 cylinders, so that leaves fuel.

Yes that is simplified but look at the most likely first.

I would take that carb apart and clean it out good, blowing out every passage.
When you put it back on make sure it is sync'd with the other side.

How long have the carbs been on the car?
Did they run good before?

Years ago (really it was decades ago) I put some 34s on a Baja Bug. After installation when I started the car it just ran on 2 cylinders, took me awhile to figure out I was getting no fuel from 1 carb.
One of the carbs new out of the box had a blocked fuel passage to float valve. What ever they used during manufacturing was never cleaned out. I had to drill out the passage and fit anew plug where I drilled from. For some time after that a small piece would come loose and stick in the float and flood the carb.

Jim

[rhodyguy]

If the idle air mixture screws have no effect when you seat them, first suspect is plugged idle jets.

[Hine62]

Thank for the replies. When it stops raining I'll look into the carb more. It's possible that it is plugged some where.

[914_teener]

Raining hunh.....

How old is the fuel?

[Hine62]

If the idle air mixture screws have no effect when you seat them, first suspect is plugged idle jets.

Checked the idle screw on the suspect carb, no change. Time to pull it and give it a good cleaning...

[Hine62]

The rain finally stopped.. (IMG:style_emoticons/default/tongue.gif)

So I pulled the carb and gave it a good cleaning again. No change... Pulled is again and inspected the screw below which is actually the idle jet. Cleaned it up and ran a pin through the holes. No change, but I did notice that the holes could be lined up with the circuit. Turned it out a bit and the idle circuit started to work again.

Thanks for all your help. I'm glad this was an easy fix.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i1279.photobucket.com-15000-1527167844.1.jpg)