16v twin 40s

I have just put a KR engine runing twin 40s in my mk1 gti,the problem is that it wont start,it keeps backfiring really bad! i have used the 16v loom,coil,and ecu,ive wired the green on the - ,the black,black/white on the + of the coil,ive also kept the gti wires on the coil aswell,i seem to have spark,not sure if it anough tho.
 The fuel side i have fitted a uprated pump,so i know i have planty of fuel,but it still backfires!
 I would be very greatfull if some one could give me some help.

sounds like the timings out matey, or you may have the leads on wrong  :dontknow:  defo check the timing, and the leads are you sure the carbs are jetted up proberly?

Thanks for answering!the leads are in the right order,the carbs came with the engine when i bought it,the guy said it ran good,i will cheak the timing tho.Thankyou for your help

Check the dizzy is not 180 degrees out - check auxillary shaft timing and that the rotot are is pointing at no 1 lead when the engine is at TDC on the compression stroke.

Thankyou for your help i will check the dizzy out!

when you say uprated pump have you've fitted a lower pressure one like a facet one?

Yes it came with engine,and carbs i wired it up on the oringal gti wires,thanks for your reply

just wondering , dose it backfire through the exhaust or througt the carbs, .ie. spit the fuel out the carb throats.

It backfires through the exhaust big time,more so when i give it more throttle.Thankyou for your reply

svr6 said

It backfires through the exhaust big time,more so when i give it more throttle.Thankyou for your reply

Sounds like lots of fuel in the exhaust manifold burning off compression - i.e. spark or valve timing is way out

Was the engine complete when you put it in or was it stripped?

I would agree that your timing is out somewhere, though if the engine was all together and you just dropped it in… :dontknow:

What have you got controlling the ignition? Mk1 TCI or 16v? Or has it got an old "points" dizzy converted to fit?

Thanks for you info, i overhauled the engine before i put it in,all the  timing marks lined up,im going to cheak again tho just to make sure! im using the 16v dissy,and loom witch i think ive wired it up ok,cause ive got spark.