Curious timing question... - PeachParts Mercedes-Benz Forum

vwbuge · #1 10-02-2007, 01:53 PM

My VW buggy has been running a little crappy. I still have a backfire on trailing throttle and she spits and sputter at half throttle. She also will not idle when the choke is off. She will scream at full throttle though.

Anyway, I went to check the timing. I noticed the notch in the dist. for No.1 cylinder. That corresponding plug does not go to cyl. no.1. Could I have wired reversed and it still run the way it does? I have to dive back into my idiot manual.

G-Benz · #2 10-02-2007, 04:27 PM

The firing order is 1 - 4 - 3 - 2...you can reverse a couple of wires and still get marginal performance (amazing little engines, aren't they)?.

The notch is for #1. If I recall, #1 is the far cylinder on the left bank (staring at the engine from the rear). #2 is the near cylinder on the left bank, then #3, the far right bank, and #4 the near right bank.

The cylinder head tin has each cylinder number stamped just under the spark plug recesses.

t walgamuth · #3 10-02-2007, 06:14 PM

on a four cylinder, if you reverse the wires it will probably not pull the car.

it sounds like you may have the timing off and it also sounds as if you have a massive vac leak. I would put a vac guage on it and see what you find.

If you have one in the hole for four and the dist body is twisted far enough as long as the firing order is correct it will run. but the timing may be way off.

you may need to start at square one, by putting the no one cyl at top dead center, and putting the distributor so that the rotor points to the number one hole in it. then follow with the other cylinders in firing order. then you can time it.

Tom W

vwbuge · #4 10-02-2007, 10:00 PM

I have looked over and over for a vacuum leak and it is driving me freaking nuts. I started the car and it would idle with the choke on and I sprayed every gasket and joint with starting fluid and no change. I don't know what to do anymore.

Chas H · #5 10-02-2007, 11:49 PM

#1 is on the right side of the engine when standing at the rear of the car looking fwd.
On some VW engines the timing is slightly skewed for #3, because it runs hotter. But that is not the cause of your problem. You likely have some crud partialy plugging the main jet. There may be other jet pluggings too, so I suggest you pop them out and blow thru everything with a shot of air. And check for power to the electric idle jet if it's got one.

vwbuge · #6 10-03-2007, 08:00 AM

That has been done. I have a 34-pict-3/4 and I pulled the idle screw and bypass screw on the left side of the carb. I shot carb cleaner in there and then blew into them with compressed air.

I guess I am going to pull the carb. I don't understand it because the carb is less than 10 years old.

G-Benz · #7 10-03-2007, 09:33 AM

What kind of intake runners do you have? The early steel ones had pinhole leaks that would create all sorts of vacuum issues. I had a hairline crack on one of my cast intakes that caused hard starts and rough idle issues. Wouldn't have seen it unless you puuled the carb and intake off the motor.

Also what kind of distributor are you running? OEM centrifugal or 009? If the breaker plate on the distributor (centrifugal) is shot, it won't advance the timing the way it's supposed to.

Also, are you running single or dual carbs?

vwbuge · #8 10-03-2007, 11:52 AM

Quote:

Originally Posted by G-Benz

What kind of intake runners do you have? The early steel ones had pinhole leaks that would create all sorts of vacuum issues. I had a hairline crack on one of my cast intakes that caused hard starts and rough idle issues. Wouldn't have seen it unless you puuled the carb and intake off the motor.

Also what kind of distributor are you running? OEM centrifugal or 009? If the breaker plate on the distributor (centrifugal) is shot, it won't advance the timing the way it's supposed to.

Also, are you running single or dual carbs?

Aluminum intake. I don't think there are any leak issues there. I sprayed everything down pretty good with starting fluid. No changes in RPM.

I have a 009 dist.

Single carb. 34 pict 3

I think I might take it apart, clean it and put it back together and then worry about the timing.

crash9 · #9 10-03-2007, 12:57 PM

Pull the dizzy and tear it down. Sounds like the advance is stuck at full advance.

vwbuge · #10 10-03-2007, 02:01 PM

I am perplexed. I consulted the idiot manual and the notch is for no1 cylinder. I then ran the plugs in firing order to their perspective cyl. It won't start.

Something is screwy. In the meantime I ordered a rebuild kit for the carb. The buggy does sit all winter so maybe things are a bit gummed up in there.

G-Benz · #11 10-03-2007, 02:40 PM

What kind of motor do you have? 1600 dual or single port? Oversized pistons?

I'll have to go look at mine again to see where everything should be oriented...distributor marking, cylinder locations, etc.

Note, I'm running dual Weber 34ICTs on a 1641cc motor. If one carb goes bad, I can still run somewhat on the other...

vwbuge · #12 10-04-2007, 08:26 AM

1641cc, same as you. Nice looking motor.