Trouble after BAP install
08-15-2010, 07:01 AM
#1
2nd Gear Member
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Join Date: Jun 2007
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Posts: 155
Trouble after BAP install
Hey guys
I need some help. I have had some issues with my fuel pump maxing out. So bought and installed the KB BAP 20 amp.
Install went fine and when i testet it it had fixed my duty cycle. At 20-25% bap setting it was at around 90% duty cycle under wot at 5900 rpm. It was running perfectly.
Now comes the trouble. On the way home after test i ran into an e55 amg. It was to good to pass up. I just couldn't resist and also had him by several car lengths. However something went wrong in 3rd or 4th i could hear it on the exhaust note it became more hollow all of a sudden.
Now the car is stuttering and hesitating when trying to accelerate. It becomes worse when the engine is hot. Its basically running like crap.
I searched the forum and came up with a whole bunch of things to look into, but I would like some opinions before i start tearing everything apart.
I wired the bap in before the FPDM. Could my FPDM be fried, but stil functioning?
I attached a datalog in case somebody has the skill for that.
Im running around 410 rwhp (or was ;-)).
I need some help. I have had some issues with my fuel pump maxing out. So bought and installed the KB BAP 20 amp.
Install went fine and when i testet it it had fixed my duty cycle. At 20-25% bap setting it was at around 90% duty cycle under wot at 5900 rpm. It was running perfectly.
Now comes the trouble. On the way home after test i ran into an e55 amg. It was to good to pass up. I just couldn't resist and also had him by several car lengths. However something went wrong in 3rd or 4th i could hear it on the exhaust note it became more hollow all of a sudden.
Now the car is stuttering and hesitating when trying to accelerate. It becomes worse when the engine is hot. Its basically running like crap.
I searched the forum and came up with a whole bunch of things to look into, but I would like some opinions before i start tearing everything apart.
I wired the bap in before the FPDM. Could my FPDM be fried, but stil functioning?
I attached a datalog in case somebody has the skill for that.
Im running around 410 rwhp (or was ;-)).
08-15-2010, 10:28 AM
#2
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
I would do a compression check to rule out mechanical damage before working on the engine control side of things--at 410rwHP you are right up against the breaking point.
I looked at your logs and only two things stand out: the idle speed is rather high at 1100-1150 RPM, and the short term fuel trims are most < 1 (I.e. negative percentages) and at times as much as -20 to -22%. This indicates a mostly to very rich mix.
I seriously doubt that the FPDM could be "fried. but still functioning"--it's basically a PWM to analog converter, it would either be broken or not. Also the fuel pressures are what one would expect with the BAP.
At idle it's a smooth 50+/- 2psi (which explains the STFTs at idle)
In the "drive" log it drops off to 39psi at what is obviously a sharp deceleration (load = 0.09%), and peaks at 64psi just after a throttle "blip" (at 29.39s). The load jumped to 100%, fell in the next sample to 75%, then 50, 36, and 22% within 1.5s--I suspect the fuel pump control system could not react to the change fast enough.
Did you retune for the BAP, the average fuel pressures are consistently around 50psi, that's 10psi over what a stock or "normal" tune would expect.
First however do that compression check...
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What is the "Analog 1" input?
I looked at your logs and only two things stand out: the idle speed is rather high at 1100-1150 RPM, and the short term fuel trims are most < 1 (I.e. negative percentages) and at times as much as -20 to -22%. This indicates a mostly to very rich mix.
I seriously doubt that the FPDM could be "fried. but still functioning"--it's basically a PWM to analog converter, it would either be broken or not. Also the fuel pressures are what one would expect with the BAP.
At idle it's a smooth 50+/- 2psi (which explains the STFTs at idle)
In the "drive" log it drops off to 39psi at what is obviously a sharp deceleration (load = 0.09%), and peaks at 64psi just after a throttle "blip" (at 29.39s). The load jumped to 100%, fell in the next sample to 75%, then 50, 36, and 22% within 1.5s--I suspect the fuel pump control system could not react to the change fast enough.
Did you retune for the BAP, the average fuel pressures are consistently around 50psi, that's 10psi over what a stock or "normal" tune would expect.
First however do that compression check...
-------------------------------------------
What is the "Analog 1" input?
08-15-2010, 12:25 PM
#5
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
What confused me about Analog 1 values was that in the "drive2" log it looked like AFR, but in the "idle" log it recorded numbers in the 1.8 to 2.7 range--knowing that it's an LC-1 it appears the number in the "idle" log are the raw voltage output.
This formula; Analog1 / 5 * 15.14 + 7.35 will convert it to AFR.
08-15-2010, 12:42 PM
#6
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
There are dedicated data logging devices, some standalone and some PC-based. I have 2 PC-based units. One is called OBD-2 Vehicle Explorer and was developed by a fellow named Alex Peper, I've had mine for over 12 years now and it still works as intended. The last software update was in late 2009, but there's been nothing needed to be updated since then.
I have the TriCAN, Tricom and Indo-3 interface.
The other PC-based tool is the Delta Forces Data Scout logging system--which is on sale for $170 this month.
I also have an older stand-alone logger made by Snap-On which now is pretty much just a paper-weight--it doesn't weigh enough to use as a boat-anchor.
------------------------------------------
In the interest of full disclosure I need to acknowledge it was I that designed the original concept for the DFS interface's electronics, and wrote the software.
I have the TriCAN, Tricom and Indo-3 interface.
The other PC-based tool is the Delta Forces Data Scout logging system--which is on sale for $170 this month.
I also have an older stand-alone logger made by Snap-On which now is pretty much just a paper-weight--it doesn't weigh enough to use as a boat-anchor.
------------------------------------------
In the interest of full disclosure I need to acknowledge it was I that designed the original concept for the DFS interface's electronics, and wrote the software.
08-15-2010, 01:54 PM
#7
2nd Gear Member
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Join Date: Jun 2007
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Posts: 155
Take a good look at the plugs too, they may tell you something--you may find some damage...
What confused me about Analog 1 values was that in the "drive2" log it looked like AFR, but in the "idle" log it recorded numbers in the 1.8 to 2.7 range--knowing that it's an LC-1 it appears the number in the "idle" log are the raw voltage output.
This formula; Analog1 / 5 * 15.14 + 7.35 will convert it to AFR.
What confused me about Analog 1 values was that in the "drive2" log it looked like AFR, but in the "idle" log it recorded numbers in the 1.8 to 2.7 range--knowing that it's an LC-1 it appears the number in the "idle" log are the raw voltage output.
This formula; Analog1 / 5 * 15.14 + 7.35 will convert it to AFR.
One thing that confuses me is the FPUMP ACT VOLTAGE. How do you interpret that? it can't be real voltage to the pump it seems way to low.
08-15-2010, 07:47 PM
#8
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Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
Yes, I use the SCT livelink software to datalog and I have to set the formula manually everytime. It appears i forgot when doing the first idle log. I usually set it to (V*3)+7.35
One thing that confuses me is the FPUMP ACT VOLTAGE. How do you interpret that? it can't be real voltage to the pump it seems way to low.
One thing that confuses me is the FPUMP ACT VOLTAGE. How do you interpret that? it can't be real voltage to the pump it seems way to low.
I am not at all familiar with SCT's products, however there is no PID of which I am aware that provides the actual fuel pump voltage, so I don't know where they are getting that number.
I do know that the signal the PCM sends to the FPDM is between 5 and 51% duty cycle to operate the pump, and that the FPDM doubles this value to control the pump's operating speed. This is a closed loop control system with the PCM receiving real time feed back from the fuel rail pressure sensor.
Here's the description from the shop manual:
PID 1672 reports the fuel pump duty cycle, however that is the duty of the PCM's signal to the FPDM and really should be doubled to arrive at a value representing the pump's actual performance.
08-30-2010, 12:48 AM
#9
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Join Date: Jun 2007
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Posts: 155
Still haven't fixed this, but I have a few clues now to go on.
I did the compression test and cylinder 1 -7 were 150 psi and 8 was 141, but i did have some issues holding the tool down in that cylinder. It seems too little to be the cause, but i dont know.
I have done some more data logging and have found that it is running a little richer than it used to under wot, but at aroun 4500 rpm it will consistently start going lean (between 11.5 and 12.5).
Another fact is that the issue increases with the temperature of the engine. It runs almost normal when cold.
Could be a leak somewhere? although I would think that it should go rich instead of lean since its boosted.
Anybody got any bright idea? I have kinda run out.
Here is my mod list
Vortech V2 SQ
Vortech 3.33 6 Rib Pulley
Power Pipe
Paxton A/A Intercooler
Maxflow Racing Bypass Valve
SVT Focus Pump
Kenne Bell BAP 20amp
42# injectors
90 Milimeter Lightning MAF
NGK-BR7EF Spark plugs
Patriot 3650Extreme transmission from Americanpowertrain
Aluminum Driveshaft
70 mm TB and ported plenum
I did the compression test and cylinder 1 -7 were 150 psi and 8 was 141, but i did have some issues holding the tool down in that cylinder. It seems too little to be the cause, but i dont know.
I have done some more data logging and have found that it is running a little richer than it used to under wot, but at aroun 4500 rpm it will consistently start going lean (between 11.5 and 12.5).
Another fact is that the issue increases with the temperature of the engine. It runs almost normal when cold.
Could be a leak somewhere? although I would think that it should go rich instead of lean since its boosted.
Anybody got any bright idea? I have kinda run out.
Here is my mod list
Vortech V2 SQ
Vortech 3.33 6 Rib Pulley
Power Pipe
Paxton A/A Intercooler
Maxflow Racing Bypass Valve
SVT Focus Pump
Kenne Bell BAP 20amp
42# injectors
90 Milimeter Lightning MAF
NGK-BR7EF Spark plugs
Patriot 3650Extreme transmission from Americanpowertrain
Aluminum Driveshaft
70 mm TB and ported plenum
09-07-2010, 01:44 PM
#10
2nd Gear Member
Thread Starter
Join Date: Jun 2007
Location:
Posts: 155
Just for the record.
I got this fixed. Or rather it fixed itself. Over time the problem lessened and went away.
My theory is fuel or air got where it shouldn't have due to the extra fuel pressure introduced by the BAP. Maybe fuel were pushed into the vacuum side of the FRPS or in some other way messed with the sensor, but i dialed down the BAP a notch and will have to see if the problem returns.
I got this fixed. Or rather it fixed itself. Over time the problem lessened and went away.
My theory is fuel or air got where it shouldn't have due to the extra fuel pressure introduced by the BAP. Maybe fuel were pushed into the vacuum side of the FRPS or in some other way messed with the sensor, but i dialed down the BAP a notch and will have to see if the problem returns.