Just returned from central day

I think I have a problem with the ignition amp on my car, after the engine has been running for a good while, lets say 1 hour down the motorway for example,


The car develops a missfire/back fire always ar 4000rpm, I have upgraded to a gpa coil, new champion qc59c plugs, the cap and arm are new. I have renewed the heat conducting paste for the module.

When the misfire kicks in the rev counter normally drops to zero for a second.

I've had a read on google and a site mentioned cooling the ignition amp with water, this helped whil the engine was revved up in my garage.

Anybody come across anything like this before??

Its on a cosworth managed cvh turbo

 

In what way did the water/cooling help, did you drive the car afterwards to see if it had cured the misfire ?
It could well be the amp breaking down, but would have expected it a lot sooner, where abouts have you put the amp, maybe it is a area where it is collecting a lot of radiant/transfered heat ?
Does it only play up when hot ?, maybe try another one, a known good one.
tabetha

 

when the misfire starts it will even do it when revving stationary, the water test was simply pouring a couple of pints of cold water over it as it was running and revving, to which it did appear to help for a brief period.

The amplifier is mounted on the n/s inner wing in its own clear space

I can't find the spare I had to test as that was my first thought, I will replace it as a matter of course, even if to just eliminate it,

Cheers tabetha

Stu