Troubleshooting Help Needed

[mrblyoung]

Hey Guys!

I am working on getting my build up and running after a hiatus.

Build:
2276cc (Super Squish Pistons, Steve Tims Stg 2 Heads, Web 86B, A-1 1-5/8" Sidewinder, Dual CB 40mm Throttle Bodies, 30# Injectors, Microsquirt ECU)

After diagnosing that my wideband was faulty (always read at 7:1 - swapped to a different one and reading fine) and that supplying the MAP sensor with a vacuum line from only one TB was a problem (readings bounced from 60-80 kPa, now with T from both it reads exactly 69-70), I am on to my next handful of issues and figured you guys might be able to help me.

1. Cutting out/Popping - The car runs pretty smooth up to 3000 RPM's, but over that it starts to cut out and we get Lost Sync Counter numbers start to pop up. The car is at my buddies place and we have been tuning it with his laptop, I am trying to get the datalog files from him to post here in hopes that it might help.

I need to do a little bit more research to try and determine what Lost Sync Counter issue I am running into and best way to read that information.

2. Pulse Width - I was searching here on this site to see what the normal pulse width is for our cars, and have come up fairly empty handed. What do you guys typically see? My buddy that is helping me with this tuning (Does a lot of Subaru swaps and uses Micro/Megasquirt for all of his builds) states that he typically sees a Pulse Width at idle is 3-4 for his Subaru builds, but on my car it is showing a Pulse Width at idle of 8. Is that problematic?

3. Fuel Pressure - What are you guys typically seeing for your Fuel Pressure when the car is running? I am running a Radium Fuel Pressure Regulator with Gauge (http://www.radiumauto.com/Fuel-Pressure ... -P229.aspx) and a Walbro Fuel Pump. When I turn the car on, the fuel pump will prime up to 50PSI and will drop down to 43.5PSI (3 BAR) once the pump stops. Well last night while we were running the car, we looked at the gauge and the needle was sitting over at 70 PSI. Is this something to be concerned by?

Trying to knock this out one step at a time. Any help is appreciated!

[Jadewombat]

The fuel pressure is a little high, 35-40 would be better. What are you using for ignition, RPM pickup?

[Chip Birks]

What are you using for crank trigger?

Set fuel pressure while the car is running. 70psi won't do any damage, but probably bumps your pump way out of its efficient range.

[mrblyoung]

Whoops. My bad.

Full Mario setup for crank trigger. Machined wheel in back of Berg Equalizer pulley and LS2 coil packs. Wasted spark and triple checked that the correct banks are paired together.

[mrblyoung]

Set fuel pressure while the car is running. 70psi won't do any damage, but probably bumps your pump way out of its efficient range.

That radium FPR isn't adjustable. It just has an OEM Bosch 3 Bar regulated top on it. If it's seeing more than 3 BAR when running, should I assume the Bosch regulator it uses is faulty?

[jhoefer]

Lost sync at higher rpms, with a VR sensor, can sometimes be corrected by adding a 10k resistor inline with the VR signal wire. Also, make sure your VR wires are not near plug wires, and you are using shielded cable from sensor to MS.

[mrblyoung]

Lost sync at higher rpms, with a VR sensor, can sometimes be corrected by adding a 10k resistor inline with the VR signal wire. Also, make sure your VR wires are not near plug wires, and you are using shielded cable from sensor to MS.

Found the Lost Sync Reason gauge last night. Kept giving us a #2, which is Missing Tooth at Wrong Time.

I have one of Marios harnesses that has each connector having its own seperate little harness that are twisted with braided mesh coverings on each. If the VR wire bundle is touching a spark plug wire, would the braided mesh covering keep this interference out, or would I need something more heavy duty to keep these signals from interfering?

I will take a look at it tonight/tomorrow to see if they are touching the spark plug wires. The LS coils have the spark plug wires going around the back of the throttle bodies, so it might be touching the VR wire bundle.

[Chip Birks]

Could also be a tooth gap issue.

[Clonebug]

How much endplay do you have on your engine???

If too much your could get too much gap when depressing the clutch or when engine spins at higher rpm.

As Chip says......check your gap and tighten it up to the minimum gap instead of toward the looser side.

[Piledriver]

The VR line doesn't have to be touching the plug wires to see noise.
It just has to be in the car.
The shielding helps reduce the noise.
Ground the shield at ONE end.
Are you grounded everything to the block?
(I know the manual says to... I have personally found that not to go very well)

[mrblyoung]

Chips advice fixed the cutting out issues. We loosened the VR bracket, gapped it a little bit more and no more problems. Must have been too close to the wheel.

Clonebug, I never measured end play. The longblock was professionally built and has never seen road time so it should be dialed and ready to go. I know that's kind of a blind eye approach, but my engine builder is top notch and I have full confidence it's correct.

I still need to look into the pulse width and fuel pressure issues. Now that it actually runs and can go through the RPM range without cutting out, I think this weekend is time for the maiden voyage and first attempt at starting to tune it. Is pulse width something that can be adjusted electronically or is that something that is dictated by fuel pressure?

[mrblyoung]

Are you grounded everything to the block?
(I know the manual says to... I have personally found that not to go very well)

I have everything grounded to the battery.

[Chip Birks]

Lots of things can affect pw, fuel type, injector size, fuel pressure, fuel map vs req fuel (i could be wrong on this one). I would just get out and start driving, let VEAL do its thing, watch your afr values, pw should get to where its needed if the afr is right.

[mrblyoung]

Okay guys - back with another problem.

My car now fires up and runs. Idles at about 1000 RPM's, so now I am trying to move onto tuning. The problem is I am still facing problems with my wideband.

So I have 2 Innovate LC-2's widebands. Only using one, but I have a second one that came with my spare EFI stroker motor. The Innovate DB gauge and the gauge in Tunerstudio read 7.4 all the time. The DB gauge will blink 7.4 and then change to 7.5-7.6 after about 20 seconds. In Tunerstudio, if you change the gauge from Air:Fuel Ratio 1 to AFR1Target and back, then it reads 10:1, but the moment you fire the car, back to 7.4 and doesn't move at all no matter what the engine is doing (idle or revving).

So initially it was wired just as the microsquirt manual/innovate manual stated it should be. 12V switched power with a 15A fuse coming from my fuse panel to the RED wire. The BLACK wire wired as a Power Ground and the YELLOW wire as the input for the ECU. Followed all calibration steps by the book from Innovate to get it setup.
-30 seconds without sensor connected, red flashing lights
-Power down
-Connect sensor in free air
-Power back on
-Green flashing lights
-Faster green flashing lights
-Solid green light
-Disconnect power
-Unplug the sensor,
-Thread into bung in exhaust
-Reconnect the cable
-Turn on car

Easy enough, right? No dice. Same thing has happened repetitively even after multiple recalibration. So I figured maybe its the brain itself, so I swap out the LC-2 module for the other one I have, recalibrate it, try again. Still 7.4.

Then I figure, maybe I'm not getting good enough ground, so I wire it directly to the battery and repeat. Still 7.4 at both the gauge AND the computer.

So I figure maybe its a dead sensor. So I run the second cable and sensor (had to use the other cable as one LC-2 has a 4.2 sensor and the other a 4.9). into the car, recalibrate it, do everything by the instructions and still 7.4:1

I am about to throw these widebands off a cliff. Seriously. Anyone have any additional information that might be able to help me? I mixed and matched components, tried two completely different widebands, wired it two different ways, and all with the same exact results.

[Piledriver]

The 4.2 and 4.9 sensors use a different WB module calibration, not compatible electrically.

Haven't heard of any widespread issues with the LC-2s, but the LC-1 were trash, died like flies back when they were new, the LC-2 redesign supposedly fixed that.

Satisfied long term user of 14point7.com widebands, so far so good.

There's one flavor you can get for $35 and reuse your existing wiring if Innovate isn't any help.
They also can read sensor temperature, which is critical and can cause problems on a long ACVW header.