ECU for EFI
03-22-2007, 02:44 PM
#61
Formula One Spin Doctor
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Originally Posted by 125shifter
Thanks guys. All six plugs on the left look pretty much identical, as do the right ones. If it's an intake to head leak, I would expect to see some variation from cylinder to cylinder or would one leak show up on all 3 cylinders.
Looking at the specs for the injectors, they'll easily flow 72lbs/hr with more fuel pressure.
After I get the fuel lines re-routed, I'll log the duty cycles. I ordered the parts last night so it'll be a week or so.
One more kink to throw into the problem: With the car idling, I disconnected one injector on a left cylinder and it tried to die. When I did the same on the right it didn't
(just the opposite of what I expected since it's the left that's running lean.) Each bank runs on a separate ground wire through the bulkhead connector until all the grounds are connected a few inches from the ECU plug. My original thought was that it's a ground problem. It may still be, but with my aversion to wiring, I'd rather change the fuel lines first 
.
Looking at the specs for the injectors, they'll easily flow 72lbs/hr with more fuel pressure.
After I get the fuel lines re-routed, I'll log the duty cycles. I ordered the parts last night so it'll be a week or so.
One more kink to throw into the problem: With the car idling, I disconnected one injector on a left cylinder and it tried to die. When I did the same on the right it didn't
(just the opposite of what I expected since it's the left that's running lean.) Each bank runs on a separate ground wire through the bulkhead connector until all the grounds are connected a few inches from the ECU plug. My original thought was that it's a ground problem. It may still be, but with my aversion to wiring, I'd rather change the fuel lines first .Pull the injectors and have them checked or switch banks with the injectors .
and see if the problem is consistent......
03-23-2007, 06:32 AM
#63
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For the record, JamesE's engine runs with 3.2 Carrera fuel rails that are fed though equal lengths of aeroquip from a full flow Y connection, the fuel is supplied through a single front pump/filter that is good for 1000hp (using a Bosch 044 as a lift pump from the tank). Fuel pressure is monitored by the M600 and it does not drop under load.
03-23-2007, 06:43 PM
#64
One of the things that's a little scary about doing plug "cuts" like this is that to get the best reading, you should shut the engine off immediately after running at load, then pull the plugs for inspection. This is exactly what you *don't* want to do to the turbocharger. Every hot shutdown can cause damage to the turbo bearings and shaft. So how do you get a good plug reading without damaging your turbo?
03-24-2007, 12:27 PM
#65
Burning Brakes
Originally Posted by Rob S
One of the things that's a little scary about doing plug "cuts" like this is that to get the best reading, you should shut the engine off immediately after running at load, then pull the plugs for inspection. This is exactly what you *don't* want to do to the turbocharger. Every hot shutdown can cause damage to the turbo bearings and shaft. So how do you get a good plug reading without damaging your turbo?
03-24-2007, 09:49 PM
#66
Burning Brakes
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Originally Posted by Rob S
One of the things that's a little scary about doing plug "cuts" like this is that to get the best reading, you should shut the engine off immediately after running at load, then pull the plugs for inspection. This is exactly what you *don't* want to do to the turbocharger. Every hot shutdown can cause damage to the turbo bearings and shaft. So how do you get a good plug reading without damaging your turbo?
I watched JB do this to a turbo motor on the DTS dyno about 4 times with no problem. They analyzed the plugs with a 10x loop too.
03-24-2007, 10:30 PM
#67
Don,
Interesting. But I'm surprised that this is okay (for the turbo). I know that the turbo, if loaded, turns red within seconds of reaching full throttle. And I can't imagine a plug cut would be meaningful if the engine isn't loaded and run up through the revs. I'd be concerned that any red hot turbine, if not cooled completely, would have the potential to damage the shaft and bearing. But like David said, he's more concerned about a hole in the piston than damage to the turbo. So I guess you have to pick your poison.
How long did JB run the engine at full throttle? And was it loaded? I agree that a magnifier, plug inspection tool, or microscope are a must for this.
Oh, and did your engine have one side leaner than the other? Mine didn't. Or at least, not to a large degree.
Rob
Interesting. But I'm surprised that this is okay (for the turbo). I know that the turbo, if loaded, turns red within seconds of reaching full throttle. And I can't imagine a plug cut would be meaningful if the engine isn't loaded and run up through the revs. I'd be concerned that any red hot turbine, if not cooled completely, would have the potential to damage the shaft and bearing. But like David said, he's more concerned about a hole in the piston than damage to the turbo. So I guess you have to pick your poison.
How long did JB run the engine at full throttle? And was it loaded? I agree that a magnifier, plug inspection tool, or microscope are a must for this.
Oh, and did your engine have one side leaner than the other? Mine didn't. Or at least, not to a large degree.
Rob
03-25-2007, 09:23 PM
#68
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No, the turbo did not turn turn red/orange/etc, as the pull (remember, DTS loads the motor using recirculating water as resistance, managed by computer) only lasted 10 sec or less. I think they did 4 or 5 pulls total, to fine tune. They measure lambda, not AFR, but I think the comparable AFR was something like 12.2:1.
My side to side lean was due to elect imbalance on the injectors and plug wire connectors. Once I corrected that, no problems with side to side problems.
When I get mine back together, I have a day's free use of their dyno, WITH them tuning - not me
... Maybe I'll ask Geoffrey to fly down and be done with it...
My side to side lean was due to elect imbalance on the injectors and plug wire connectors. Once I corrected that, no problems with side to side problems.
When I get mine back together, I have a day's free use of their dyno, WITH them tuning - not me
... Maybe I'll ask Geoffrey to fly down and be done with it...
03-25-2007, 11:18 PM
#69
Formula One Spin Doctor
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Originally Posted by DonE
My side to side lean was due to elect imbalance on the injectors and plug wire connectors. Once I corrected that, no problems with side to side problems.
it...
it...
This is why i wanted shifter to have his injectors checked.
04-18-2007, 10:04 AM
#70
Burning Brakes
Originally Posted by DonE
My side to side lean was due to elect imbalance on the injectors and plug wire connectors. Once I corrected that, no problems with side to side problems.
I changed the fuel system from running in series to running parallel with a fuel damper on each rail. It's still running lean on the left and rich on the right so there was no change.
04-18-2007, 11:21 PM
#71
Formula One Spin Doctor
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Originally Posted by 125shifter
Don, what was your electrical imbalance? When I watch the voltage on each injector, they all read the same at about 13.5 volts. I thought I'd see a difference side to side but I don't.
I changed the fuel system from running in series to running parallel with a fuel damper on each rail. It's still running lean on the left and rich on the right so there was no change.
I changed the fuel system from running in series to running parallel with a fuel damper on each rail. It's still running lean on the left and rich on the right so there was no change.
04-19-2007, 08:56 AM
#73
Burning Brakes
Geoffrey, any suggestions? It doesn't seem like this is something I should just live with.
I spoke with Simon at Motec. He said if all the injectors are showing the same voltage on the laptop then it's probably not one injector bank getting lower voltage than the other.
After detailing my set up and what I've eliminated as a problem, he suggested checking the cam timing, which has also been a suggestion from others. So I'll get off my lazy *** and check that next.
I spoke with Simon at Motec. He said if all the injectors are showing the same voltage on the laptop then it's probably not one injector bank getting lower voltage than the other.
After detailing my set up and what I've eliminated as a problem, he suggested checking the cam timing, which has also been a suggestion from others. So I'll get off my lazy *** and check that next.
04-25-2007, 08:58 PM
#74
Burning Brakes
Well... so much for my wrenching skills 
.
Sure enough the cam timing is way off on the right bank. At least that's the side that's running rich, so hopefully I didn't do too much damage.
I'll be pulling the engine now and at my super slow work rate that means it'll probably be a month before I'm back on the road. Let's see... while I'm in there I'll replace the CV joints... and maybe re-gear the tranny...
The good news is: more HP!!!
.Sure enough the cam timing is way off on the right bank. At least that's the side that's running rich, so hopefully I didn't do too much damage.
I'll be pulling the engine now and at my super slow work rate that means it'll probably be a month before I'm back on the road. Let's see... while I'm in there I'll replace the CV joints... and maybe re-gear the tranny...
The good news is: more HP!!!
