crank fired backfire problem
08-02-2017, 10:35 AM
#1
crank fired backfire problem
I am having a backfire problem with my recently fuel injected s10. Anytime I mash the throttle off of idle it will backfire instantly but will then rev fine. When cruising it will backfire and pop a lot. I am clearly down on power.
I installed a crank trigger system on my 350, it's a blue print specialties engine with not too many miles on it. Some highlights are,
megasquirt 2 v3.57
36-1 trigger wheel
Hall effect sensor
d585 coils
stealt ram intake
supercoupe 32lb high z injectors
LS fuel filter/regulator
Taylor spiral core wire
coils remotely mounted
I have checked the timing with a light, checked all the exhaust connections, checked the wiring to everything multiple times, tried new coils, tried placing them in the stock location and using stock wires. I have tried everything I can think of but I have not been able to solve the backfire. I am at the point now where I am ready to pull the crank trigger off and install a HEI ignition just to simplify things.
i feel that I have my VE table close, atleast close enough that it shouldn't be causing a backfire. The Accell Enrich setting are the only thing I am unsure of. I have cut it back so far so I really don't thin they are the cause.
I set the valve lash, but I am worried it's possibly too tight. The backfire is consistent if I mash the throttle off of idle, and while cruising it will consistently backfire. When I rev it in park it does not backfire through the entire rpm range.
Does this sound like a valve adjustment problem? any help or thoughts would be greatly appreciated.
I installed a crank trigger system on my 350, it's a blue print specialties engine with not too many miles on it. Some highlights are,
megasquirt 2 v3.57
36-1 trigger wheel
Hall effect sensor
d585 coils
stealt ram intake
supercoupe 32lb high z injectors
LS fuel filter/regulator
Taylor spiral core wire
coils remotely mounted
I have checked the timing with a light, checked all the exhaust connections, checked the wiring to everything multiple times, tried new coils, tried placing them in the stock location and using stock wires. I have tried everything I can think of but I have not been able to solve the backfire. I am at the point now where I am ready to pull the crank trigger off and install a HEI ignition just to simplify things.
i feel that I have my VE table close, atleast close enough that it shouldn't be causing a backfire. The Accell Enrich setting are the only thing I am unsure of. I have cut it back so far so I really don't thin they are the cause.
I set the valve lash, but I am worried it's possibly too tight. The backfire is consistent if I mash the throttle off of idle, and while cruising it will consistently backfire. When I rev it in park it does not backfire through the entire rpm range.
Does this sound like a valve adjustment problem? any help or thoughts would be greatly appreciated.
Last edited by 91dime; 08-02-2017 at 11:49 AM.
08-03-2017, 07:20 AM
#2
Re: crank fired backfire problem
Has anyone used megasquirt and holleys efi systems? I am considering going to Holley for the better customer support, and their system looks more user friendly compared to megasquirt.