I *think* my 60# are dirty/clogged after a lot of parts replacement, testing, scanning. Everything is fine except she's running 'just' lean enough to 'lean stumble' at idle/cruise RPM's. Putting any load on the motor, from normal freeway access to 15 PSI boost, it's fine. The only thing I can think of is dirty/clogged injectors. I pulled all the plugs. Two were noticably 'cleaner' than the other 6.

I can buy the flow matched 80# racetronix for about the same price as new 60# so why not upgrade? Just wondering if you guys have had any experience with them.
Thanks,
Dave

 

Dave, those look tempting, but you should see if you can get ahold of some turn-on times for those and compare them to low impedance 80 lb injectors and maybe the 79 lb disc injectors also listed and compare them to the 60s you're using now so you don't end up with something that is too slow or imprecise at lower pulsewidths.

 

Thanks for the input Kevin. Just what is involved nowadays to convert to Low Impedence Fuel Injectors? I remember back in the day you had to buy one of those Acceleronics(sp?) boxes to make it work. If you know something off the top of your head, please share. I'll start searching around too.
Thanks!
How's your ride these days?

 

I typed in Acceleronics into google and there's his site. I remember he was on the national Fbody email list when he created this box. He's got what looks like an unbeatable deal for the box AND flow matched 95# injectors for $649.

 

Yeah Dave, with the stock computer, you'd need the conversion box to run low impedance injectors - added junk, but necessary. I guess I was thinking maybe you had an aftermarket computer by now.

My car is doing fine - runs as good as ever with no problems - there's always things I could do to it, but it's not too needy. I should redo the supercharger intake. My exhaust is a bit restrictive. I would say it was pretty much done since a few years ago. I haven't been to the track since I built the fuel system, so I am overdue to go see if I can best my last time when it was running lean.

 

I think I might get 96lb or 120lb low Z injectors and make a driver circuit so I can run E85 and 15psi

 

I found a guy that had a NIB acceleronics box and 75lb injectors that he wanted to sell but after an initial contact he stopped corresponding so I just ordered a brand new box and 95# injectors from Acceleronics

 

I have LJ's Acceleronics driver and 8 72# Semens low_Z injectors. Been running for years. I like the response time on the low_Z injectors. Very snappy on the open cycle. I think you will like it. App... 97ss 383ci - D1 MM6. B.

 

Thanks for the response. I just finished pulling out the 60# Mototrons and installed the 95#'s. I won't get to wire it up till tomorrow since it's hailing out right now (Marble and pea sized pellets) lol...

Did you find that the stock PCM offsets were fine or did you have to tweak them any to get your idle A/F ratio where you liked it?

 

Yes, I changed the offsets in the 12 to 14 volt range. A very small change for a faster injector open time.
I have been running the Acceleronics box for 7+ years.
I would recc purchase of an O2 wideband sensor to tune in closed loop mode and WOT mode, I also got that from LJ.
I have played with the OBD2 PCM quite a lot.
B.

 

Cool. I bought a wideband before even firing up the turbo motor the first time. I read a lot on the forced induction boards before getting things put together and that was manditory in my mind.

LJ sent me the offsets you're referring to so I'll put those in my tune.
Thanks,
Dave

 

Well, just finished putting the box in and wiring it up. Fired up on the first crank. Idles smoothly. After monitoring the gauges for a few minutes, I went back into the house, got my Drivers License and then walked back out to take her for a drive. Woot! The stumble is gone. Runs right at 14.5 to 14.7 A/F ratio at cruise. I went up to 13.9 psi about 3 times and the A/F ratio was 12.2 so all is well. Outstanding news for me.

 

Let's get some numbers with a little more boost

 

Dave,

Any updates? Any plan to redyno or hit the track again?

 

Lots of desire but between bad luck with weather and visiting family (my daughter is a Marine!) I haven't had a chance. The car is running great now and I'm anxious to get some more racing done. The local track (New Lebanon) has test n tune on Wed night. Not the most convenient, but maybe tomorrow night? Hope so... I swapped to a hotter plug so I need to pull a few and make sure the color indicates I'm still safe.