Took the car out today and dynoed it. This is the first time I have dynoed the new motor. Hasn't been on the dyno since December of last year when I blew the old motor up while dynoing.

I had a good idea when I went up there today as to where my HP/TQ #'s would be and was not too far off. Best pull of the day was 193.1rwhp/298.3rwtq. Now for the fun part...the pull when I got those numbers was the first pull with the Wideband hooked up. As soon as I went WOT, my A/F was about 10.5:1 and then went so rich from there it is off the chart. We did a little tweaking of the fuel pressure by adjusting the AFPR and attempted another pull and cut it short due to still being extremely fat. By the time we were done, I had adjusted the AFPR out so to the point that I can't get the adjuster screw out anymore and it is still running extremely fat. Is there anything other than getting a chip burned that I can do to lean it out more? We attempted to pinch off the fuel line with some vice-grips and still couldn't lean it out enough that way. This was done just to try and lean it out to see how much power was actually being lost due to the car running so fat.

 

No, you're pretty much done. The only other think I could suggest is that you switch to smaller injectors.

I read your sig and it doesn't look like you've done too much to it other than opening up the exhaust. That shouldn't affect it THAT much. Did you happen to put larger injectors in it? If so, I'd take them out and put the stock 22# units back in it at your current level of modifications.

Also wondering..... was your car an original L-98 or did it come with a 305 orignially? If it was upgraded to a 350 did you change the computer chip for a 350 chip at the same time? Mismatches between the chip and injectors can really cause some bad problems, even on a basically stock engine.

 

injectors are probably whats screwing ya up, and was it a 305 car? the ecm doesn't gets tricked that easily

 

You could also be starving for air at higher RPMs. Your sig does not really mention any intake mods. If you are running the stock intake system, you should have tried a run with the air filter disconnected, just pipe to the MAF sensor. That would eliminate starvation for air.

However, if it was air starved, usually the MAF would tell the engine that it does not need that much fuel. You might have a faulty MAF sensor. Do you or any of your friends have a spare that you can borrow to check with?

Apart from that, yea, you need to burn a chip.

Good luck
Troy
So Cal

 

Damon and Kretos...it was originally an L98 and has a rebuilt motor in it that i put in after blowing the original motor. The injectors that I have in it are SVO 24#...had to replace them because the #7 injector died on me.

TA...the car is a 91 therefore it is a SD car and not a MAF car. I didn't think to pull the filter off though

Thanks for the input guys. I will probably wait until after I do the next series of mods before having any tuning done or chips burnt.

 

Bingo, there's your problem. Well, part of it anyway.

Ford SVO injectors are rated at a lower pressure differential than GM injectors (37 PSI vs. 43 PSI). And they're 2# larger than your original 22# units were on top of that. Net net, I think it's the equivalent of like a 26# GM injector @ 43 PSI, higher than that if you're running more than 43 PSI at the rails.

Somebody who is smarter than me with injector math can probably jump in here and give you the true numbers.