Its definatly +/- a bit. I have tried to adjust it with no change i will check fuel trim today and see what it is. I am truly at a loss here. Thanks for your time
Fitech running fat
- Thread starter Devo44
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do you have all the wires shielded any problems I have seen from a fitech was improper installation the wires need to be shielded or you will be getting lots of interference .
Guy at fitech said if that was the case it would throw fault codes and there arent any
Not trying to side track things here, I have a Sniper system, so NOT familiar with fitech. But I had the sniper “dead headed” from the external pressure regulator like you due to being told the built in regulator would not handle the extra fuel pump volume. Holley and others said it would work. I had an issue I chased with a lean stumble on light throttle changes. It was commanding a ton of fuel in the problem area. I got to the point of putting a carb on. As a last ditch effort I pulled the guts out of the built in regulator ran full pump volume to the tbi with a return to the external regulator set at 58psi which is what Holley calls for. It cleared up every issue I had, went from commanding 80-90 pph to 25- 35. Also you didn’t mention camshaft, 13 degrees initial seems awful low with any type of performance cam. As I stated this was my experience with the sniper.
mario03srt
Well-Known Member
One other thing to try is to reset the controller. I have the instruction if you need it.
Cam is .578 230 dur 110 sep. Ran great at 13* with carb. I dont see how adding any more pressure than the 46 would help with a rich cond. Thanks for the input! I am about ready to go back carb..
I’m not an expert but if it were me I’d temporarily run a return from the tbi and see what happens. Just takes a little time to remove the regulator guts, if it’s similar to Holley, and a return line to see. It can get frustrating. Sometimes we run into issues that “tech” hasn’t seen, or don’t want to work thru. In my case it wasn’t a psi issue but I believe a volume issue that couldn’t keep up with varying demands. Have you installed a new set of plugs also.
Frank Mopar
Well-Known Member
Are the IAC steps within the Fitech specs. I would confirm this.
I ran a corvette bypass filter on mine. It was at the back of the car so a short return line is all you need. No issues.
I ran a corvette bypass filter on mine. It was at the back of the car so a short return line is all you need. No issues.
Just read through and wanted to verify the issue.
What is the relation of the displayed AFR vs Target AFR?
1. Is the system aware/displaying that it's rich, but just not capable of leaning down to the Target AFR?
2. Or is the system displaying it's at Target AFR, but is in fact rich?
1. This could be a result of excessive fuel pressure. You have it regulated down to 43psi, but I strongly suggest installing a gauge at the throttle body to ensure it is in fact seeing 43psi. Also where is the IAC?
2. This could be a result of an exhaust leak, or non-optimum O2 sensor placement. Where is the sensor installed?
What is the relation of the displayed AFR vs Target AFR?
1. Is the system aware/displaying that it's rich, but just not capable of leaning down to the Target AFR?
2. Or is the system displaying it's at Target AFR, but is in fact rich?
1. This could be a result of excessive fuel pressure. You have it regulated down to 43psi, but I strongly suggest installing a gauge at the throttle body to ensure it is in fact seeing 43psi. Also where is the IAC?
2. This could be a result of an exhaust leak, or non-optimum O2 sensor placement. Where is the sensor installed?
Yes e3s and there is already a return from the tbi to the reg.
The system displays its at target afr but still running rich. IACs are 3-4. O2 sensor is 3" behind collector, welded bung. No exhaust leaks anywhere. Thanks for your input!
Thanks. I have done that twice with no change
Frank Mopar
Well-Known Member
The handheld should read the fuel pressure.
Where would i find that? I havent seen that parameter in my handheld. Thanks!
superchargeddrt
Well-Known Member
Is your AFR reading or is it stuck at 14.7 and the exhaust smells and looks pig rich?
I had this happen to me twice and the way I fixed it was I disconnected the battery, shorted the positive and negative cables together (I used a jumper cable) for about 10 minutes. When I reconnected the battery and started it the AFR was back to reading normally and it didn't smell it look rich. Hopefully this will help.
I had this happen to me twice and the way I fixed it was I disconnected the battery, shorted the positive and negative cables together (I used a jumper cable) for about 10 minutes. When I reconnected the battery and started it the AFR was back to reading normally and it didn't smell it look rich. Hopefully this will help.
The afr is tracking but its definately wrong as its smokes and backfires randomly through exhaust. Ive never heard of shorting the + - together. How does that help? Thanks!
Frank Mopar
Well-Known Member
Maybe its the fuel pump percentage Im think of.
Looks like all bases are covered. Im going with a vacuum leak.
the system is getting a false reading. It’s either an exhaust leak, or a faulty O2 sensor. I would take a close look at the O2 sensor harness, and your headers. This is of course assuming you don’t have a dead/failing cylinder on the other bank pumping raw fuel out..
LJ67barracuda340
Well-Known Member
At idle look into the throttle bores . I had an injector go bad and was dumping fuel into the front left bore at about a cup/minute at idle. 4 carboned plugs (dual plane manifold) and the commanded AFR (14.7) was staying rich (12.5). put a new injector in and problem solved.
superchargeddrt
Well-Known Member
Shorting the cables together (after you disconnect them from the battery of course LOL) will help drain the capacitors in the system and will make sure the system resets. Give it a try, it can't hurt and it worked for me twice.
famous bob
mopar misfit
initial caught my attention !!
Have you considered a hotter plug ?????
67Dart273
Well-Known Member
I ain't no expert but.........
Some big cam engines have problems with a MAP sensor. Google up alpha-N. Is the FItech capable of that? I did not look it up. On Holley, you can operate Alpha-N at lower RPM where the cam is giving the MAP problems, and switch to "density" under better vacuum conditions.
Also it might be just as simple as an in-accurate O2 sensor, or as said above, a bad choice of mounting
Some big cam engines have problems with a MAP sensor. Google up alpha-N. Is the FItech capable of that? I did not look it up. On Holley, you can operate Alpha-N at lower RPM where the cam is giving the MAP problems, and switch to "density" under better vacuum conditions.
Also it might be just as simple as an in-accurate O2 sensor, or as said above, a bad choice of mounting
I don't think it's an IAC issue. If the system was unable to achieve Target AFR, then I'd look there. Basically the system is happily doing what it is supposed to, adjust fueling to reach it's Target AFR. The problem is, it's not accurately sensing the AFR. Fresh air is being introduced on the monitored bank altering the AFR, the sensor is faulty, or that monitored bank is actually at correct AFR but the other bank has a dead/failing cylinder or other issue pumping fuel into the exhaust. My money says it's an exhaust leak.
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