Rough Running

[nealf]

Hello all..If anyone was following my plight to install an OEM distributor last week and the frustration I had, it is finally over as I found TDC by pulling the valve cover and lining up the cam/rockers. The car started immediately and I was real happy. I did this whole distributor thing because someone had installed a Roto Faze one on my car and I thought the contact button in the motorcraft cap was failing. The result was backfiring, non idiling, and general rough running.

Much to my surprise, the car is running the exact same way with the OEM bosch '002' distributor. I had thought it could have been a weber carb problem but many told me it was an ignition problem. WHere do I go from here? The timing is pretty correct, wires all look good as does cap, points, not sure about condensor though. Also the coil is not a Bosch unit. Would that make a difference?

Thanks.

nf

'70 2800CS
'73 2002

 

[jhjacobs]

What you are describing sounds very much like a timing problem. It is unlikely that the ignition (points, coil, rotor, cap, etc) are the culprit at this point since it is starting. How did you set the timing? You normally need to disconnect the vacuum lines to the distributor, plug them, and then hold the engine around 1700 rpm while strobing the timing light on the timing ball(s) through the flywheel portal. If you set the timing at TDC rather than 22 degrees before TDC, you will get carb backfiring (I've done this several times thinking it was correct). The flywheel marking can be confusing when setting the timing. On mine it is a single silver ball that shows up. To check to see it you got TDC rather than 22 degree before simply try rotating the disctributor about 20 degrees counterclockwise and see if it improves.

Some other things to re-check:
- Plug wire order is correct?
- Pull the plugs and look for serious fouling.
- Run a compression test while plugs are out - should be about 9-9.5:1 +/- 5%.
- Make sure both carbs are providing fuel - you can look into each throat carb and push the throttle linkage; you should see the accelerator pumps squirt some fuel (not a perfect indication but it confirms the float chambers have fuel
- Double check you CAM timing. When I got my E9 the chain was off a tooth. With the engine at TDC (flywheel or harminoic balancer indicating) the #1 CAM lobes should be down (or up) and the chain pully bolt should line up with the milled notch on the head.

 

[Malc]

Coil shouldn't make that much difference. If it has an internal ballast resistor you should be ok, if it doesn't you MAY go through points pretty quickly.
As to the condenser I would change it anyway, are not expensive, a quick and easy job to do.

Do try JHjacobs checks first, only thing I would say is you compression values are going to be around 170 - 190psi cold /hot and I would only start to get worried if the difference between any cylinders was more 20psi.

If the car is sorted great if not below I have thrown out some stuff to think about! :roll:

In regard to the carbs make sure they are balanced, and the throttle linkages are working, ie they open and close at the same rate. Spark plug colour a good indicator of mixture setting

From memory Webers are pretty sensitive to dirt in the fuel so they may need a clean out. Then fit a good in line filter if you haven't got one. Also they don't like air leaks either - all gaskets in good shape? Inlet manifold ok?
Malc

 

[velocewest]

Cam timing confirmed correct?