just was wondering if any one had any ideas on how to solve the problem I'm having with my 1200 coupe rally car! It has an a12 running twin dellortoes, electronic ignition, electric fuel pump from a s2 blubird and running on Shell optimax fuel.

Symptoms:
it is pinging all through the rev range even with light load, running hot, missing slightly and lost a bit of power. When i pull the plugs out to check them they are clean. The tacho (aftermarket VDO) swings around past 10,000 when your probably only doing about 4-5,000 RPM and is very jumpy.

Other Info:
To me this would seem to be running lean. This happened at a rally so we first tried changing the fuel filter and spark plugs and finished the rally. This had no effect. At home we tried many things like:
-bypassed the fuel regulator.
-checked the fuel pressure was between 2-4psi while driving.
-cleaned and blew out main and secondary jets in carbies
- checked the float level
-checked the condition of the softmounts
-checked the tension on the manifold nuts
-checked the ignition timing(only at idle)
-checked the distributor advance weights and springs.
-tried a different distributor, leads, coil, ignition module.

all of the things we checked or tried seemed to be funtioning correctly but made no difference with the car. the only thing that changed was the taco seemed better after changing the ignition system.

If you've read this far, thanks for taking the time to read and any help or suggestions you can give to rectify this problem will be greatly appreiciated!

On a better note the little 1200 finished the rally in 7th outright out of 37 and we were the second 2 wheel drive behind a v8 commodore.

To see photos from the rally go to Mfoto under the heading Dell Clasic Stages view cars 000 to 19. We were car 12 a green and white 1200 coupe.

the pinging not sure that i czan help you, but if the tacho is jumping around, it is either cactus, or the wiring is dodgy. Redo/check the wiring for that, and if it still does it, rewire to to another car to check, if that test fails, then ditch it.

My ute did the exact same thing when I installed a tacho and I found out that I had wired it wrong and it was sucking the power from the dizzy. So I would start there.

I encountered similar symptoms three times where it was blocked exhaust. Twice it was the heat riser valve in the manifold, another time it was a partially crushed exhaust pipe.

How would fuel problems cause the tachometer needle to jump around? Isn't the needle controlled solely by the points/current flow through the coil?

I had similar symptons with the tacho as well as hard to start when hot. The problem turned out to be the luminition that i was running for a ignition system . If you put the timing light onto the front pulley does the timing mark jump around erratically? I replaced the luminition with a Ignitor (brand name in nz)that sites in the dizzy, Solved the problem.

Paul.

thanks for all your suggestions i haven't had another chance to look at it yet but hopefully i'll get some time tonight or tommorrow. I'm thinking there is an air leak somewhere in the intake system and have a few things to check. One of the main things may be the carbies could have worn around the butterfly shaft and possibly leak air.

Has anyone ever heard of this happening? Has anyone ever had problem with their fuel pickup inside the tank?