- Thread starter
- #21
Brand new complete kit from Howell.
Real mechanic in DFW (Howell FI swap) (1 Viewer)
- Thread starter JasonH
- Start date
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- Thread starter
- #22
OK, I'm back looking at this. Thanks for the help so far. I did finally figure out how to monitor this via TunerPro. I did a baseline and adjusted the IAC and the TPS position. TPS is roughly .6 at idle. The baseline idle was way off. I believe the O2 sensor is working correctly. It goes to closed loop and it fluctuates between roughly 100 and 800 mV.
The main thing I see so far that is off is the BLM and INT values. They start at 128 which is where they are supposed to be, but the both tend to climb to around 140 when running, which I believe means it's detecting a lean condition, so it starts adding fuel to compensate.
The O2 sensor is just downstream of where the manifold "donut" gasket is. I replaced that relatively recently, so I don't think it's leaking, but it's possible. Maybe it's getting air from there. I'm not sure what to look at next.
Idle is pretty good. Still have to barely touch the gas when leaving a stop. Once underway, full throttle causes it to surge.
The main thing I see so far that is off is the BLM and INT values. They start at 128 which is where they are supposed to be, but the both tend to climb to around 140 when running, which I believe means it's detecting a lean condition, so it starts adding fuel to compensate.
The O2 sensor is just downstream of where the manifold "donut" gasket is. I replaced that relatively recently, so I don't think it's leaking, but it's possible. Maybe it's getting air from there. I'm not sure what to look at next.
Idle is pretty good. Still have to barely touch the gas when leaving a stop. Once underway, full throttle causes it to surge.
BLM and INT are long term and short team fuel trims.
Scanner Danner on youtube has some solid videos on troubleshooting using fuel trims.
I would do two things next:
1. Check for vacuum leaks using a smoke test, this is pretty easy to do with a paint can and a bicycle pump, or a cigar.
2. Check the MAP sensor and make sure it's reading correctly. I know you said it was new but it's still worth checking.
If you're hitting a lean condition that is causing fuel trims to be outside of norm it's usually it's either unmetered air or a bad sensor. See what the calibration is on the MAP sensor and make sure it's set correctly.
BLM & INT - could someone confirm how they work? - TunerPro User Forum
forum.tunerpro.net
Scanner Danner on youtube has some solid videos on troubleshooting using fuel trims.
I would do two things next:
1. Check for vacuum leaks using a smoke test, this is pretty easy to do with a paint can and a bicycle pump, or a cigar.
2. Check the MAP sensor and make sure it's reading correctly. I know you said it was new but it's still worth checking.
If you're hitting a lean condition that is causing fuel trims to be outside of norm it's usually it's either unmetered air or a bad sensor. See what the calibration is on the MAP sensor and make sure it's set correctly.
- Thread starter
- #25
Previous mechanic spent a lot of time on the phone with Howell, but I blame the mechanic more than Howell.
The update is that I had it running for a while. I put a gopro under the hood with the air cleaner off and watched the fuel cut off when I gave it gas. It wasn't able to keep up with the initial demand. The fuel filter ended up being clogged (remember this is a new system with very few miles on it). I replaced that filter and added a second filter right at the throttle body to act as a reservoir to absorb some brief high-load situations. It ran good for a few weeks then it killed the fuel pump. I haven't had a chance to replace it yet. The fuel in the front tank was pretty old but there wasn't much left in it. So instead of draining it I just filled it back up. I guess it still doesn't like that fuel. I may have to drain that one when I replace the pump and see what happens.
The update is that I had it running for a while. I put a gopro under the hood with the air cleaner off and watched the fuel cut off when I gave it gas. It wasn't able to keep up with the initial demand. The fuel filter ended up being clogged (remember this is a new system with very few miles on it). I replaced that filter and added a second filter right at the throttle body to act as a reservoir to absorb some brief high-load situations. It ran good for a few weeks then it killed the fuel pump. I haven't had a chance to replace it yet. The fuel in the front tank was pretty old but there wasn't much left in it. So instead of draining it I just filled it back up. I guess it still doesn't like that fuel. I may have to drain that one when I replace the pump and see what happens.
