[swinginbeef]

I'm having a fuel issue and I'm not exactly sure why. My car is continually getting richer and richer. I recently changed to 42.5# injectors and am trying to tune them to the 3.25 pulley that I currently run. With my AFC set to 94-95%, the new injectors should flow similarly to stock (from what I understand). I've got to set the AFC all the way down to the mid 80's to get my LTFT's close. If I set my AFC to 95% at WOT my O2's are 1000+ up to 1015! What could be causeing my car to dump so much fuel?

Another thought I just had was since I'm having trouble taking away fuel, what if I tried adding air and dropping pulley sizes instead??

 

[BIG JEFF]

Howdy,


What injector constant is in your p.c.m. ?


BIG JEFF

 

[swinginbeef]

I currently have DHPv1 with nothing changed. It should be programmed for stock injectors. I've had this richening issue since I first cracked a piston several months ago. I've since replaced with a used long block from Ed, but am still having the fuel issue.

 

[Buick 1]

I'm having the same issues. Did you notice this more after installing your S1X cam. (no i'm not saying it's the cam but maybe a tuning issue)

 

[swinginbeef]

Yes, I think this issue started when the cam went in. I don't think I had this issue before the cam install, though I didn't own a scanner and very rarely scanned before that.

 

[Merc]

Joe since you have the 2.0, What are you settings? Are you running in Normal or Advanced mode?

 

[swinginbeef]

I recently decided to try resetting my PCM and start over on the tuning. I reset the AFC (advanced mode) to 95 across the board and let it run for a day and then scanned. All my LTFTs were almost -20. I dropped down to 92 and 91 where the LTFT were worst and drove for 2 days and rescanned. My trims were then down to -11.7 to -17.6. I adjusted several more percent on Friday. My idle is at 89 and my crusing ranges are down to 87. I drove all weekend and scanned this morning and my LTFT's are still averaging -4.6 to -8.0.

I'm going to keep tuning down until I get it to 0 and then let it go for several days and then scan again and see what happens. I'm thinking that maybe last time I tuned, I wasn't giving the computer enough time to learn the new curve and adjust LTFT accordingly. We'll see what happens. Last time, I'd get my tune to close to 0 and then a few days or a week later, my LTFT would be rich again by quite a bit. I still don't understand why I'm having to tune away so much fuel. What else would low MAFF affect? Doesn't that affect shifting also?

 

[Buick 1]

On a side note after the cam install did you have problems with your tranny not wanting to shift at wot?

I also found these two posts from the national board. I don't know if it will apply in your case but found it interesting.
#1...
I have run across similar problems in my car as well as another locally, however both cars ranged from decently modded to HIGHLY modded and both used DHP pcms. The issue I was experiencing was that the car just stopped accelerating around 104-107mph. I spent a great deal of time fighting this trying different pcm's, plugs, gaps, ect..... Everything on scans seemed to look normal from 02's, IPW's in there proper ranges to no detected misfires or Kr. Finally I found a solution when I hooked up my afc 2.0 and reduced the high bands to 98%. After that the car kept pulling hard till I let off the gas. The other car that had these same issues was remedied in a similar fashion(slightly reducing fuel at WOT).

Being as close to stock as your car is I somewhat doubt that you are having a similar problem but you may want to keep it in the back of your head
#2....Doing some research, made some interesting finds...It seems like such a mystery what works or doesn't on our cars. I'm posting this to save you'all the time I spent...

Ford injectors ARE interchageable, as long as they are the Bosch style.
High impediance injectors are not all the same. Ohms ratings vary from 11-16.6ohms. Stock ohms is 16, most ford are 14.6ohm.

"Competition" injectors are around 12ohms.

You should choose an injector as close to the OEM spec as possible. The lower the ohm rating of the injector, the faster the response time from computer command (sounds like a good idea huh? Not so...) A lower ohm injector will cause premature failure of the injector drivers in your cars computer. The lower ohm injectors don't have enough resistance, and in daily use may overheat the drivers, and render the computer garbage.

I found 2 Lucas PN's that will work, and are safe:
8f160-038 (38#/hour)
8f160-042 (42#/hour)
Both are rated at 16.6 ohms

Bosch pn:0280150558 (42#/hour)
rated at 14.6ohms, this is the stock injector on SC Ford Lightning.

Hopefully this info helps someone, and prevents any failures
Ron

 

[swinginbeef]

On a side note after the cam install did you have problems with your tranny not wanting to shift at wot?

I did not have this problem.

 

[Merc]

Joe have you checked for a vaccume leak? What are your IACs?

 

[swinginbeef]

I had a vacuum leak about a month and a half ago that came about when I installed the Shortstack I/C. That leak has been fixed and my IAC reads in the mid 50's when the car is warm and idles in drive. I've sprayed the entire engine with carb cleaner and I am 99.9999% sure I have no vacuum leak.

 

[PGA2B]

Your scans are looking much better Joe!! We'll continue to adjust your AFC2.0 and get you to 0 LTFT Have faith!! Tuning is not a switch you can just throw. You have to adjust, run, scan, and tune!!

HANG IN THERE!!