need help! car runs on 2 cylinders? Options

[TravisG]

HI all,

Just getting the car back together, can"t get it to idle, so I took off the carbs cleaned all the jets and passages, put back together, cranked the car and it revs up to 3000 rpms, try adjusting the carbs to idle down and find out that cylinders 3&4 do not affect the rpms (IMG:style_emoticons/default/confused24.gif) Then I take off the 3&4 spark plug wires and the engine still runs 3000 rpms no difference in motor HELLLPPPPP

[Dave_Darling]

Fuel, spark, compression--one of those is missing. Figure out which one.

--DD

[Heeltoe914]

Gotta love carbs........ Has to be one of the three above if not. comppression????

[TravisG]

Thanks, the only thing I haven't checked is the compression. The motor has just been rebuilt. It was upgraded to Mahle, 8 to 1 compression p&c's, so I hope it is not the compression.

Here is what I checked so far:


I pulled the plugs and there is spark, but there is no smell of gas on them, however when it is running, I can see the gas spray in the throats of the webers. I just cannot understand how the engine can run so smoothly and rev so nicely with just the 1&2 spark plug wires hooked up. Just really frustrated at the moment. Got to the point of almost literally (IMG:style_emoticons/default/headbang.gif)

So I decided to back off for tonight and get some different inputs

[Dave_Darling]

Check the valve adjustment. Also look for vacc leaks at the manifold or at the carb on the non-functioning side.

You can also try the "poor man's compression test"; listen to the sounds the starter makes while cranking. If the sound is uneven ( "RR-rr-RR-rr-RR-rr" ) that is an indication of low compression on two cylinders. It's a lot more obvious if only one is dead, BTW: "RR-RR-RR-..-RR-RR-RR-.."

How's the timing? Static timing good? Are those two cylinders firing on something near TDC?

...That's all I can think of off the top of my head...

--DD

[TravisG]

Thanks Again, Am off to work now. Will be back home at 6:00 pm will get to work on it again then. Will keep updated on progress.

[r_towle]

Firing Order...check that first.
Make sure its 1432 clockwise looking from above at the cap.

Carbs,
looking down the throat, when the car is idling....when you open the carb on the side that does not seem to be running, do you see (look down the throat of the carb with a flashlight) a small squirt of fuel when you initially open the carb?

Check the inlet fuel supply filter where you attach the fuel hose....its a small screen that can get clogged.

Float level, this is a very common error that lots of people do not do right. Pull the top cover off and measure and fix the float level. Most carbs are wrong from the factory...

I am not quite understanding how your car idles. If it idles at 3k rpm, you need to fix that first.
Remove the cross bar linkage (disconnect the drop links)
get a syncrometer and check each throttle tube on each carb to see how much air it draws...this is another good diagnostic tool to see if your valves and rings are correct....if on cylinder is way below all the others...stop and fix that.
If one side is way below the other...stop and find the leak.

Rich

[TravisG]

Thanks For All the Advice.

I switched the carbs from side to side and then the 3&4 cylinders ran and the 1&2 cylinders didn't. So my problem is one of my carbs. Time to do a complete rebuild. I am both happy(knowing what is wrong) and sad (down time in ordering kit and rebuilding), But at least there is a light at the end of the tunnel (IMG:style_emoticons/default/piratenanner.gif)