Blue Flames Between Shifts

[1HOTSVO]

If I drive the car hard and shift around 5.5K I am backfiring and blowing blue flame out the exhaust.
The timing, fuel pressure and all the things I can think of are dialed in.
The car is highly modified but backed down to 240RWHP for the street so I can run 91 fuel.
I have all the goodies: Big valve head, Header, stage 3 turbo, 3" exhaust, etc., etc....
The only thing that I do not like about my set up is that I am running 42lb injectors but have not changed the EEC to compensate for the injectors. Could the extra bit or fuel cause this?
This is on an 86 SVO with only about 30K miles on it.
The biggest concern is what can I damage if this continues?!
Thanks,

Brian

[svono50]

Brian,

You already pointed out your problem...the 42lb/hr injectors with a stock EEC. Your car will run pig rich with those injectors. This is loading up your exhaust with raw fuel which is igniting when you let off. While this is good for spooling up your turbo, it is also very hard on it and the exhaust system. You could damage your exhaust valves, exhaust manifold, turbo and exhaust piping if the backfire pops in the wrong place.

I would suggest getting a chip, EEC-Tuner or something to properly compensate for the bigger injectors. Just my $0.02.

[svobud]

Originally posted by svono50
I would suggest getting a chip, EEC-Tuner or something to properly compensate for the bigger injectors. Just my $0.02.

or....my $0.02...drop back in the 35lb-ers - with less than 300rwhp. They can handle it.

[1HOTSVO]

I figured that was where the problem was coming from I just had no way to test the theory without spending $500 on the EEC tuner and software.
I planned on doing that soon anyway since I am sure it I will be able to tune the car better and gain more power.
I think the injectors may also be causing a problem on my bottom end with loading up and acting like a dog while I am trying to get off the line. What do you think?

Thanks!
Brian

[svono50]

The 42's will definitely load you up at idle. The EEC can only adjust the injector pulse width so much and 42's are outside that range, so you end up with excess fuel.

The EEC tuner is probably the cheapest route to tuning your car for the larger injectors. One of the owners of AutoMotoSports, Martin, put an EEC tuner on his Merkur and pulled another 35 hidden HP out of it, so it does work.

The excess fuel, depending on how much, can end up washing down your cylinder walls of oil and cause excessive ring and bore wear. Just another side effect to think about.