520R SV build has commenced

[JohnCh]

Thanks, but I'm not using that controller.  Since I have a return system controlled by a pressure regulator, SBD had me replace it with a normal relay that the MBE still controls for on/off only.  The thinking is that if you are in a crash that kills the engine, the MBE will cut power to the pump and stop it from emptying the tank. 

 

The fact that the terminals on top of the tank, which feed the pump, were still showing 12v when the engine was going full lean and stalling, and not going to 0v until after the engine stops, makes me think it's the pump or an in-tank connection.

[sf4018]

2 hours ago, JohnCh said:

Thanks, but I'm not using that controller.  Since I have a return system controlled by a pressure regulator, SBD had me replace it with a normal relay that the MBE still controls for on/off only.  The thinking is that if you are in a crash that kills the engine, the MBE will cut power to the pump and stop it from emptying the tank. 

 

The fact that the terminals on top of the tank, which feed the pump, were still showing 12v when the engine was going full lean and stalling, and not going to 0v until after the engine stops, makes me think it's the pump or an in-tank connection.

Can you give some detail on the new relay - what type of relay and where you installed it? I need to do the same thing and control the pump run command from the ECU.

 

For me SBD had a 420 race setup but it was quite far off in the end. He spent 3 hours tuning the cold start, warm start, low rpm stuff in one session at the house then another 3 hour session for the full mapping and tuning on a dyno. Very expensive. But haven’t had any issues since.

[MV8]

I guess you confirmed the pressure drop during the lean spikes with the data log? No intermittent on the injector common B+?

[JohnCh]

1 hour ago, sf4018 said:

Can you give some detail on the new relay - what type of relay and where you installed it? I need to do the same thing and control the pump run command from the ECU.

Here is what SBD told me:  

"Because you are going to be using a normal fuel pump and regulator, I have programmed the same pin to be simple on/off output to control a relay that you will have to fit which will replace the standard Ford electronic fuel pump control module. Please note that this will be a switched ground as all output are on the 9A4 ECU. "

 

I used this waterproof relay and located it in the same location as the control module next to the tank.  I have the wiring information with color codes in my notes.  Happy to dig those out if you need them.

 

As for SBD being pricey.  Don't get me started.  Unlocked ECU was 583 GBP, the special sauce cable to connect it to a laptop is 160 GBP, and the map was an additional 320 GBP.  Any support is extra.  I don't recall the exact price but it was in the 125 GBP per hour ball park.  By comparison, the Emerald is 695 GBP for an ECU with a lot more features (4 wheel traction control, switchable maps on the fly, knock control, etc.), the laptop connection cable is 20GBP, and they give you starter maps gratis.  They also don't charge for support and when I have offered in advance to pay for some extra help if needed, I was always told not to worry about it.  

 

Unfortunately, getting SBD to do a live session on roads is difficult for me.  As @Croccan attest, cell service is really poor in my area.  I may still use SBD to help with the dyno session.  

 

-John

[JohnCh]

24 minutes ago, MV8 said:

I guess you confirmed the pressure drop during the lean spikes with the data log? No intermittent on the injector common B+?

 

I didn't add a fuel pressure sensor (hindsight...).  However, when testing in the driveway I pulled the bonnet and could see the fuel pressure regulator gauge from the driver's seat when leaning forward.  It fell off a cliff when the lean spikes hit that led to a stall.  To be fair, there was a slight lag as I looked to the gauge, so I won't claim 100% certainty, but it's close.  

 

The pump is out of the tank and the fuel is evaporating.  I'll pack it up tomorrow and send it back for evaluation.  

 

-John

[MV8]

If the problem persists after the new pump is installed, I'd use a dvm (and run jumper leads so the meter can be right in front of you) to monitor the pump B+ at the relay output. If that drops during the lean spot(s), then monitor the ecu ground to the relay or jumper to ground for testing to see if the intermittent issue is the relay or the ecu.

 

An rpm drop during a lean spot would not cause the fuel pressure to drop unless the ecu broke the FP relay ground because the ecu momentarily lost the crank trigger input, B+, or any grounds.

[JohnCh]

Thanks, @MV8, this is essentially what I did earlier.  I didn't have jumper leads long enough to place the DVM in my lap, but it did reach the back of the tunnel.  As the issue would start, I could swivel my head to see the reading.  The initial diagnosis made while watching the fuel pressure gauge was what led me to do the DVM setup.  

 

The logs show a very minor rpm dip (100 rpm?) when the spikes were brief.  Here is an example I screen captured when going over the logs from an early drive on Saturday while chasing the initial mixture issues.  The spike doesn't go fully lean, reaching about 1.12 and lasted nearly a second.  

 

 

This next one shows when it led to a stall while driving.  As you can see, it started to lean up which led me to add a small amount of throttle then some quick blips to see if anything would change as the revs went to zero.

 

 

And lastly leading to a stall while idling.  I'm not sure if I intentionally blipped the throttle, or that was a result of me moving in the seat to look at the DVM or the fuel pressure gauge.  That said it is very brief - 1/10 of a second? -- and with no ramp or fall off.   Can that happen with a mechanical throttle setup?  I'll look for more examples like that when I have time later.

 

 

-John

[JohnCh]

I looked at ore of the logs and that really rapid TPS spike frequently occurs after the engine has gone full lean and is stalling.  An example is below. 

 

 

I then tried to rapidly blip the throttle to see if I could replicate that instant increase and decrease.  As you can see, they are not that instantaneous.  BTW the grid lines in both screenshots represent 1.25 second intervals, but I can't get the SBD graphing software to make the grid lines the same width.  The scaling appears to be tied to the length of the logging session and this one is too short, slightly increasing grid line width compared to the previous screenshots.  The nature of these spikes makes me wonder if it's an artifact from how the ECU reacts as it's shutting off from rapidly reduced crank speed.  Any thoughts?  

 

 

The fuel pump went back to Deatschwerks yesterday.  I hope to hear back from them in about a week.

 

-John

[JohnCh]

Just heard back from SBD regarding scheduling time to go over my questions.  I was wrong about the hourly rate I mentioned earlier.  It's 160 GBP for "up to an hour." That's over $200 at the current exchange rate.  As @sf4018 wrote earlier, very expensive.

 

-John

[MV8]

I would have replied sooner but work has kept me in the road a lot this week.

Where is the MAP and how is it connected? With speed density, MAP response time is critical and can be affected by placement. I put the map as close as possible to the manifold and use aluminum tubing with short pieces of rubber hose on each end to connect it.

I don't know how they utilize lambda or if they use a wide band instead of an oem type but generally, when in closed loop and less than 50% throttle, it is a minor fuel control (8-10%) for keeping the mixture appropriate for the catalytic to function properly and deal with altitude/density changes and engine wear. I doubt this ecu has a learning function that would make placement distance from the head critical for reaction timing. Are you reading a second o2 that is a wideband and down stream from the control o2? I don't know how much control you have with this ecu but I'd try temporarily disabling the control 02 for testing. This can be done by changing the value that the 02 must reach to enable it's use by the ecu. Record all before making any changes. This is only for "repair" testing. If the problem continues, it is not the 02 system causing the stall.

Tps is a high wear item in an environment with vibration and large temp changes. The resistance can have spiking values when they are bad. I don't know the tps source. I would have used a common, easy to find oem tps for max reliability. You should be able to slowly rotate the tps checking for jumps in resistance with the logger, engine-off.

[JohnCh]

Thanks @MV8, a few additional details based on your advice.  This is a TPS-only system using a Colvern unit which is the common TPS on Jenvey installations.  That spiking is only occurring after the Lambda has started going lean.  It's normal everywhere else, so at this stage I don't think it's a TPS issue, but I have spares in case that becomes a problem.  Lambda is provided by a single WBO2 with an AEM X-Series EUGO controller feeding the MBE which SBD programmed to read based on AEM provided calibration data.  At this point, things are run open loop -- i.e. it is purely in read mode so has no impact on running conditions.

 

I also went through all the other logged data and everything appears normal.  No unexplained corrections, temperature spikes or dips, no error codes, etc.

 

Thanks,

John

[MV8]

I thought this was the mbe9a4 which has map, temp, and baro inputs?

[JohnCh]

Inputs, but not that implementation.  The MAP sensor used by Caterham is actually a combination sensor that is used for barometric and air temperature.  Load Site is only controlled by TPS.

[MV8]

I guess no actual map because they chose not to have a common manifold to show manifold pressure across all cylinders or even one cylinders map as a general reference.

 

I'd go back to solving your original finding (intermittent fuel pressure) first.

[Anaximander]

JohnCh, I feel your current pain! Not to derail your thread but I recently completed a Stalker AXR with a L33 engine upspec'd with a ghost cam and upgraded top-end components (rockers, pushrods, trunions, etc.). It came with a FiTech 70001 fuel injection system and self-learning ECU. I have successfully autocrossed the car x3 but found that it was running rich on the driver's side bank and lean on the passenger side. After numerous FREE (sorry about what the Brits are charging you per hour for consultation and the exorbitant fee to unlock the ECU) calls and re-reading the installation manual, I came to the conclusion that my O2 sensor wires may not have been sending the ECU the proper information since the 70001 is designed for a single passenger O2 sensor but is pre-wired for a second O2 sensor. I called FiTech a couple of days ago and reported the rich/lean condition with no faults being shown except occasional rough idle because the self-learning ECU was keeping it fairly OK. I asked the tech if it would be OK to switch the driver O2 to the passenger O2 sensor and vice versa. He said it couldn't hurt anything. Well, I did it and voila, everything is now working harmoniously. There was one sentence in the install manual that stated that if the O2 wires are crossed with no explanation of what that meant, you can get a rich/lean condition. So, doing a simple switch allowed the complete system to really start learning what AFR's are optimal at idle and in all other conditions and it has achieved stoichiometric mixture at idle which is defined as an 14.6 AFR ratio. If you have an install manual with your ECU and wiring harness, maybe be on the lookout for something as simple as the one sentence I found imbedded in 19 pages of instructions. Much good luck with the fettling. 

Edited July 3, 2023 by Anaximander

[JohnCh]

Thanks @Anaximander , those little things are always the hardest to track down.  I'm using the Caterham ECU with a revised map from SBD who distribute that ECU.  The installation is factory until the fuel pump, and the only electrical change in that ecosystem is swapping the PWM module with a relay still controlled by the ECU.  The initial running issues feel like they are down to the map which will be sorted on the dyno.  My objective was simply getting it running well enough that it can be safely driven there. 

 

The issue that has me on hold appears to be the fuel pump.  If that's not it, I'll confirm with SBD if the odd TPS spikes when the engine is stalling are normal or indicate an issue elsewhere, including with the ECU.  If that is also a "no", there are a few other things to test once the fuel pump is back provided the issue remains somewhat repeatable.  Intermittent issues are always a challenge.

 

-John

[sf4018]

The Lambda drifting to lean over a few seconds looks like the fuel psi dropping away to me too than a tuning issue. Don't know how much effort it would be to bypass the ECU pump run command and just have the pump run full time temporarily to see if it's a problem with the ECU output and/or rear relay.

[Anaximander]

John, You were mentioning that you had to swivel your head to see the fuel pressure gauge. How about just pointing a GOPRO at it while you do the various manipulations you want to do, orally let the GOPRO know what things you are changing and then correlate your fault conditions with the GOPRO recording of the fuel pressure gauge?

Edited July 3, 2023 by Anaximander

[JohnCh]

@sf4018 that's what I plan to try if Deatschwerks states the pump is ok.  My initial assumption was that's the issue, but then testing with the multimeter showed 12v at the pump terminals (post relay) while the engine was dying, rather than immediately prior.  If the pump checks out okay, then I'll assume user error with that reading (twice!) and bypass the relay to see what happens.

[JohnCh]

The full plan if the pump checks out is to

1. Get SBD to confirm the TPS spikes are not indicative of an issue.  If they are not, then:
2. Try getting it to repeat the issue while driving on my property with bonnet removed and action camera affixed to windscreen, pointing downward at the fuel pressure gauge and streaming live to my phone.  Using extensions currently on order, place multimeter in front of me and attach the alligator clips to the fuel pump terminals.  If still inconclusive:
3. Plumb in a fuel pressure sensor to log everything and confirm that fuel pressure issues do not occur prior to Lambda going lean.