gq patrol/ ford maverick 93 model

hi paul, i have a 92 maverick and had the same problem back in early may last, had a new dissy cap and rotar fitted and has been 100% since. the told me the spark had to be 100% for gas and it did effect it on petrol as well. hope this helps .
petza

Hi sarg, i can sure share your frustration with the problem u have been having. Not sure if my problems are similar due to the fact my 89 Petrol/Gas is a points distributor model. Anyway here goes for what its worth. After getting our GQ last year a few weeks later the car started missing. As we were doing a flinders trip the following week i got a mobile mechanic out to sort it out. Points and a heavy duty new coil as well as a new coil to distributor lead. Car seemed ok so off we went. Only travelled 50 or so k's and car started backfiring thru carby every now and then.RAA called out and no fix could be done so they gave us the name of a mechanic in Port Augusta to try and solve the prob. $300 later they said it was fixed. Extended rotor button new points again and a dyno. Off we went again. Still stuffed. GRRRRR Anyway i ran home on petrol which whilst it still backfired a bit seemed slightly better. Took car to gas mechanic and they put 9.5mm leads,new plugs,new points (again) new distributor cap reset valve clearances, and they also found a vacuum hose from the distributor was split.($230). Now the car actually was fine for a month or so. Then started missing again.Called RAA and they told me the coil was faulty. So new coil and still no good. Final chapter is that i forked out $350 and put a electronic ignition kit in called an ignitor and touch wood have had no more problems.(wish i had done it ages ago) As you have a 93 model which i believe has an electronic ignition i would be concentrating on coil(which u said was new) distributor cap and extended rotor button(bosch make one) make sure your leads are at least 9mm and that plugs are ok.Also check for a split in a vacuum hose as this was the cause of my car backfiring.(a fault not picked by a dyno test??) Good luck mate and i hope some of this is helpful to u. PS Only let a gas mechanic tune your car.

I agree with Brew69's comments above wholeheartedly. I too had similar problems for a long, long time with similar short-term fixes which seemed OK for a while but nothing fixed it permanently - until I fitted the Ignitor electronic conversion about a year ago. Since then I have had no more problems so I highly recommend this option. The car not only runs smoother, but also returns better economy. I suspect that the problem has something to do with the wiring and/or connections somewhere in the circuit (read voltage drop??). While I did replace the fusible links in the ignition circuit, I didn't replace or check any other wiring. Fitting the ignitor system replaces all the wiring between the coil and dizzy so that may be a good place to start looking for possible wiring problems.
Chhers and good luck.
Gerry