As the title says, I get loads of backfire over 4k rpm, and I thought it could be the two extra butterfly valves in front of the throttle valves on the secondary ports. First I thought it was the secondary injectors not spraying, but that shouldn't cause backfire, rather hesitation or stalling at 4k rpm.

So the only thing that seems logical is the thermowax or something being old and grumpy making my car act up.

Not cold start, but the extra valves keeping me for revving the engine too hard when cold, if these are stuck I dont get enough air: http://www.rx7.org/Robinette/double_throttle.htm

Also, vacuum simplification, can anyone dig up a proper pic of how to do it? I am considering blocking off the three in front of the engine on the intake, both ends, and remove the three solenoids at the oil filling neck, will that be enough?

I have all the block off plates on my intake anyway, so the three going in the back of the intake towards the old BAC and that stuff has been plugged for a long time.

Jim, Norway

 

did it just start happening? recent engine work? my guess would be a timing issue / crank angle sensor / or too lean. does it back fire off throttle or under throttle?

http://www.rotaryresurrection.com/2n...s_removal.html

 

Check TPS

 

It backfires only over 4k RPM. Of course if it is coming down from higher RPMs and I then slam the throttle down, it backfires, but which turbocar doesn't?

How can I check the TPS?

 

LOL I Mixed up alot of names. BAC is ofs the blowoff, kept that (tho not stock).

But the emissions stuff, ECR and sub-zero start is gone.

 

Removed the butterflies, but not the dashpot or whatever it is called, just to be sure I had free flow through all the intake runners at all times.

No difference.

Now I have adjusted both TPS (full and narrow range) to some random guy on the internet's guide, 0,8V on full range, 1V on narrow. The narrow was in spec with 5k Ohms WOT, so at least the TPSes works.

 

Gas smell in oil, I see many people complaining about it, but they all say it is not a problwem, what do you think about that?