Matts440
Well-Known Member
Is it only going rich when the meth kicks on?
7875 + 5.9 + E85 + Megasquirt
- Thread starter subcom
- Start date
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Actually right before, but the meth definitely makes the mix richer.
Matts440
Well-Known Member
Oh okay. Yeah just thinking maybe jet down the meth a little to help bring the afrs back to normal.
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Here's a log of when i hit 11psi. You can see where the afr dips to 10.1. The EGO correction looks like it's taking away fuel but it's configured to only adjust 25% so it may not be able to take enough away. What my tuner said may make sense as well. Some other factor is influencing this because the same tune (VE table and AFR) was working fine a few weeks ago and never went this far rich. I just got some fresh E85 and measured it and it's E85 on the dot. I have a fuel pressure gauge but it would be better if I was inputting that fp into the MS so I could log it and see exactly what it is at different boost levels. Those were the two variables my tuner thought might be at play; fuel pressure and E85 mix.
TT5.9mag
Two atmospheres are better than one
If you make a change in the ve table can you make it trend lean? Seems if it was an outside variable you wouldn’t be able to correct for it. But if you’re targeting 11.6 and it’s running 10:1 the ecu will pull fuel and try to correct it. I would make a large percentage change in the ve table across a few cells and see if I got a change. Maybe pull 10% and run another log.
When I ran the log against the tune it’s sitting mostly in just two VE cells when it goes rich which are higher than the adjacent ones. One of my strategies is to pull a little fuel from those two cells and see how AFR responds.thanks
baby got new street shoes.
Matts440
Well-Known Member
Man that's a clean ride. Total sleeper look
Turbosmblk
Well-Known Member
Subcom. I may be way off here, but are you getting your map reading before or after the throttle body? Only reason I ask is I have the same throttle body as you and when I removed the breather tube it was VERY easy to remove. I only wondered because at higher pressures it may be causing a boost leak and if the reading is pre tb it would think you were at X psi when you could potentially be way less depending on how much leakage you were getting. Just a thought??
Got one run in last night and then developed a valve train noise so I put it on the trailer. Lost the time slip but it was like 7.50/104mph. Peak pressure was 11psi @ 20 degrees timing. Looking at the log this morning I learned a few things.
1.) I wired a fuel pressure sensor to the Megasquirt and logged that. Learned that FP is spiking under really low pressure and aligns with the really rich AFRs. As psi increases, fuel pressure falls back into place along with AFRs.
2.) I hit the rev limiter at the end of the track and the ecu was pulling timing for almost two seconds at the end of the run. I had set the limit at 6000rpm with a 200 rpm hysteresis and my rpm was within those margins for quiet a while. So, gotta bump that up a little. 6200 next time.
3.) I really pussy-footed the pedal. I came out of the hole really soft and even still broke the tires loose. My '60 was like 2.00s but throughout the rest of the run my TPS never went over 80% and was mostly around 75%. It's like something fell behind the pedal and blocked full travel cause I always try to push the pedal through the firewall and usually get 97-100% tps. Definitely left some power on the table.
Gonna pull valve covers today and see what's going on under them. Sound is def valve train but I checked torque converter bolts while at the track just in case, 'cause that one has bit me before and can sound deceptively like a valve train noise.
1.) I wired a fuel pressure sensor to the Megasquirt and logged that. Learned that FP is spiking under really low pressure and aligns with the really rich AFRs. As psi increases, fuel pressure falls back into place along with AFRs.
2.) I hit the rev limiter at the end of the track and the ecu was pulling timing for almost two seconds at the end of the run. I had set the limit at 6000rpm with a 200 rpm hysteresis and my rpm was within those margins for quiet a while. So, gotta bump that up a little. 6200 next time.
3.) I really pussy-footed the pedal. I came out of the hole really soft and even still broke the tires loose. My '60 was like 2.00s but throughout the rest of the run my TPS never went over 80% and was mostly around 75%. It's like something fell behind the pedal and blocked full travel cause I always try to push the pedal through the firewall and usually get 97-100% tps. Definitely left some power on the table.
Gonna pull valve covers today and see what's going on under them. Sound is def valve train but I checked torque converter bolts while at the track just in case, 'cause that one has bit me before and can sound deceptively like a valve train noise.
TT5.9mag
Two atmospheres are better than one
Sucks about the new valvetrain noise, do you have any guesses what caused it? Over rev it at all? Your fuel pressure spiking has my brain hurting. I see a lot of “not enough fuel pressure” but rarely do you see a spike large enough to move the afr very far. What regulator are you using?
No idea on the valve train noise source. Hoping it’s a loose rocker and nothing deeper then that but it’s hard to pinpoint. But no over reving. I have both rev and boost limiters enabled and they work instantaneously on the Megasquirt. The boost limiter is set to cuts fuel and spark.
FPR is an older Aeromotive boost ref model. Pretty common part no. Just don’t recall which. I don’t have the pressure sensor calibrated perfectly but I wanted to at least see how FP trends in the logs and that spike is hard to explain but it is happening. First order of business will be to just break it down and clean along with both fuel filters. Also, I’m not controlling the fuel pump cycles from the MS. It’s on full power, full time.
TT5.9mag
Two atmospheres are better than one
Sometimes with certain aeromotive regulators, you can thread in normal length fittings that will interfere with the movement of the regulator. They’re pretty specific about using short fittings. Just a thought. But I would definitely start there.
Found source of valve train noise.
https://youtu.be/o8kLz3Xo9Cs
https://youtu.be/o8kLz3Xo9Cs
8AN feed and 8AN return at the FPR.
dusted
Well-Known Member
Glad you found it. I have boxes of lifters if you need some spares.
Just buttoned up the install of a Hughes roller rocker setup with hardened pushrods and better lifters. Got it all from a buddy for a song.
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