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Sun Oct 25, 2009 1:22 am

ok so i have done alot of searching with no answers i have a 1600 dual port 009 34pict my timinmg set at 7.5 BTDC valves are set .006 i have spark and fuel but no fire on the #4 cylinder i dont know what esle to check please HELP!!!!

Sun Oct 25, 2009 1:31 am

what is the compression?

Sun Oct 25, 2009 1:38 am

IT'S 115

Sun Oct 25, 2009 7:02 am

vwforlife8769 wrote: i have spark and fuel but no fire on the #4 cylinder i dont know what esle to check please HELP!!!!

Don't know; I've never had one cylinder fire and not the others. How do you know #4 isn't firing? I presume you know that one isn't firing because it runs like crap, and you know it's #4 because that exhaust is cold?

Anyway, I presume you've pulled the spark plug and made sure that it's something sensible? It could be the spark plug wire. You could switch the wires (at both ends) between cylinders 3 and 4 and see of the problem moves with the wire.

Also check under the distributor cap to see if the contact for #4 looks different than any of the others.

Sun Oct 25, 2009 9:59 am

I just went through the same thing about 2 weeks ago on my 70 bug. It has a 1500 SP and # 4 would not fire. The po had a dist with the Pertronix system in it. I had a used dist on the shelf with points, installed it and the bug has been running great.

Sun Oct 25, 2009 11:51 am

could be a faulty plug or wire. i know you said you have spark but the wire could be broken and when you tested for spark, moving the wire caused the break to go away momentarily.

Sun Oct 25, 2009 3:01 pm

pull the plug after you give it gas while no running and if its wet then your not getting spark. to see if its the plug or the wire. pull the wire off the plug and ground it then turn the car over. if you see a little spark then its your plug and not your wire. also check your dizzy cap to see if its damaged on 4 cylinder

Sun Oct 25, 2009 6:00 pm

thanks for all the help i think it might be the wires when i ground the spark plug there is spark i will change the wires and let you guys know thank again

Sun Oct 25, 2009 6:09 pm

Check the inside of the distributor cap for arc lines or a bad #4 terminal.

Also, I have seen on a rare occasion the spark plug itself go bad. Sometimes the conductor will crack inside the plug.

Swap wires and plugs with #3 and see if the problem moves w/ the parts.

Sat Oct 31, 2009 8:04 pm

yea so replaced all ignition stuff still wont fire could it be a lifter

Sat Oct 31, 2009 8:06 pm

the reason i think its a lifter when i first got the motor it had a broken adjustment screw on one of the rockers on the #4 cylinder

Sun Nov 01, 2009 10:17 pm

If you suspect a valve, remove the rocker assembly fron the left head and lay a straight edge across the tops of the valves. They should all be even. If one is lower than the rest it is suck open. If one is sticking up further than the rest it may have sunk into the head.

If you suspect a lifter is getting stuck, re-install the rockers and set valve gap. Compare the rocker arm angles of intake/exhaust for each cylinder... they should be about the same at TDC. You an also look at how much the adjustment screws are extending from the rockers. If one is shorter than the other this could indicate a lifter getting stuck.

Mon Nov 02, 2009 8:45 am

It's ok to check the valves, but theoretically if you have a stuck lifter, you should have close to zero compression on that cyl, and you stated it was 115 psi.

Tue Nov 03, 2009 1:41 am

the head on the number 4 side is new so i dont think it is a valve. i had the same problem before i replaced it. when i pulled the head the piston looked good not burnt no dents or dings like it hit a valve. my rings were good its really weried i will check to see if the rockers are even i have another set of rockers maybe i will change them i im down to try anything before spliting the case