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View Full Version : C16SE problem with misfire at high revs....



Racingdrivermatt
14-07-13, 10:39 AM
Ok here goes...

I have a Formula Vauxhall single seater race car, all has been running ok for several seasons util the last two races when the engine develops a misfire in the higher rev range after the first few laps have passed.

The car uses a standard 8v multi point injection unit,(I think it's the same c16se as in the gte/gsi) although the ECU is specific to the race car. So far I've tried a spare ECU, new Lucas sports coil, new distributor cap, leads, checked all earths are good, connections to the ECU are good, the charging system is good and a new battery fitted. That pretty much clears the electrical system.

The evidence now shows that the car is over fuelling, something is telling the ECU to add more fuel, the soot on the plugs and at the exhaust tip confirms this...

I tried bridging the temperature sensor to see if it was this at fault, again there was no change. In a desperate attempt to get the car back to being competitive on race day the only thing I could try for a quick fix was drill a hole in the blanking plug on the inlet manifold to forcibly add more air to the mix.

Am I missing something? Has anyone got any ideas?

One thing I could do with knowing is what ohms should the temperature sensor on the head be achieving? (Then I can rule this out) and does anyone know what fuel pressure the car runs at? I can then start to look at possible faulty injectors, pump etc....

Thanks in advance, any help is greatly appreciated...

mowgli
14-07-13, 08:20 PM
does it run a factory ecu or a specific one for racing??

does it run a lambda sensor? cos they can throw up problems.

it might be a bit oddball for us, its this one of those ones that is a lot like a formula ford, but with gm power? what series do you race it in?

Racingdrivermatt
15-07-13, 06:45 PM
Hi, the ECU is I believe a race unit, I have tried another known working ECU from a competitors car, and the exhaust is a straight four branch unit with no sensors whatsoever. This one has got me stumped!

I race in the Monoposto championship, the car is 20 odd years old now, originally the cars ran between 1991 and 2001 when the vauxhall junior series supported the TOCA touring car events.

bazil
15-07-13, 07:06 PM
Iirc the C16SE found in late GSI models ran at 3 bar ( so im led to beleive but should be confirmed ) but the C16 does not have a dizzy, coil or airflow meter

The earlier E16SE that was in GTE/GSI models ran a coil, dizzy and AFM and 2.5 bar ( same as early 20XE )

The first picture is E16 and the second C16

http://i790.photobucket.com/albums/yy181/Bazil_2468/a21.jpg
http://i790.photobucket.com/albums/yy181/Bazil_2468/gsi/Black%20gsi/P1020895.jpg