LHU Standalone-won't start

[marksawatsky]

I have built an MGB roadster race car with an LHU out of a Buick Regal Turbo. The wiring harness was modified by www.enginewiring.com to run in a standalone application. Bad News Racing has provided me with a tune that is supposed to work but so far the engine spins over, has spark and fuel pressure in the fuel rail but it won't start. When I check the DTCs it shows codes for fuel level, flex fuel sensor, evaporative emission system and fan control. I don't think any of these would prevent the car from starting but there they are. The VATS have been disabled, I have checked all connections, the battery is new and fully charged. This may help but the check engine light never comes on and the electric fuel pump is never triggered to go on, either, but there is still 1400 psi fuel pressure in the rail. Any ideas what needs to be changed in the tune? Here are some pics of the car

[JimmyS]

Where is the fuel pressure coming from if the pump is not triggered? I don't know if the fuel level code could possibly be keeping the pump from activating or not. Is the pump mounted in the tank?

[marksawatsky]

The LHU is direct injected and has an electric pump in the tank that sends low pressure fuel to the manual pump on the engine, which pumps up to 2500 psi. I manually triggered electric pump just to fill the fuel lines and the manual pump is pumping but the injectors are not opening.

[marksawatsky]

Nobody has any suggestions?

[2000Firehawk]

Info from GM:
https://www.chevrolet.com/content/da...19328839-1.pdf

http://www.chevrolet.com/content/dam...19328837-1.pdf


Fuel System:
The high fuel pressure necessary for direct injection is supplied by the high pressure fuel pump. The pump is mounted on the rear of the engine and is driven by a three-lobe cam on the camshaft. This pump also regulates the fuel pressure using an actuator in the form of an internal solenoid-controlled valve. In order to keep the engine running efficiently under all operating conditions, the engine control module (ECM) requests pressure ranging from 2 to 15 MPa (290 to 2176 psi), depending on engine speed and load. Output drivers in the ECM provide the pump control circuit with a 12 V pulse-width modulated (PWM) signal, which regulates fuel pressure by closing and opening the control valve at specific times during pump strokes. This effectively regulates the portion of each pump stroke that is delivered to the fuel rail. When the control solenoid is NOT powered, the pump operates at maximum flow rate. In the event of pump control failure, the high pressure system is protected by a relief valve in the pump.
An engine control kit p/n 19328839 is available through your GM dealer that contains a flashed ECM and engine harness to provide these functions if desired by the customer.
The fuel injection system is a high pressure, direct injection, returnless on-demand design. The fuel injectors are mounted in the cylinder head beneath the intake ports and spray fuel directly into the combustion chamber. Direct injection requires high fuel pressure due to the fuel injector's location in the combustion chamber. Fuel pressure must be higher than compression pressure requiring a high pressure fuel pump. The fuel injectors also require more electrical power due to the high fuel pressure. The
ECM supplies a separate high voltage supply circuit and a high voltage control circuit for each fuel injector. The injector high voltage supply circuit and the high voltage control circuit are both controlled by the ECM. The ECM energizes each fuel injector by grounding the control circuit. The ECM controls each fuel injector with 65 V. This is controlled by a boost capacitor in the ECM. During the 65 V boost phase, the capacitor is discharged through an injector, allowing for initial injector opening. The injector is then held open with 12 V.
See the engine controls instruction sheet p/n 19328840 for description of the vehicle fuel pressure requirements for the fuel pressure required to supply the high pressure fuel pump.


This control system is a stand alone, fully-integrated kit designed to run Chevrolet Performance LTG series crate engines with 58x crankshaft reluctor wheels, 4x camshaft indexing, and electronic throttle control (ETC). Included in the kit are the engine control module (flashed with the appropriate calibration), engine harness, accelerator pedal, mass air flow (MAF) sensor, MAF sensor mounting boss, throttle inlet air pressure sensor, fuel pump power module, fuel line pressure sensor, oxygen sensor (1), and oxygen sensor mounting boss (1), and the necessary hardware to attach the harness to the engine. This control system is intended for use with a returnless fuel system and fuel pump that is capable of being pulse width modulated (PWM) at 25 kHz to control
fuel pressure. A fuel flow rate of 32 G/hr at 400 KPa is needed. Because this is a dead headed system, a pressure relief set at 84 psi (580 KPa) must be included in the fuel line between the tank pump and the engine mounted high pressure pump. Part number 13582660 is one example of a compatible pump and it includes an integral pressure relief.
A pump with excessive capacity may result in cavitation at low flow due to the pump repeatedly stopping and starting instead of controlling to a speed/pressure. Alternatively, a fuel system operating at a fixed 500 KPa could be used and may be triggered by1the Green/Gray wire in cavity 2 of the Fuel Pump Power Module (FPPM). Note that excessive fuel heating and potential startability/drivability issues may result from a constant high pressure.
IMPORTANT: Read the ‘System DOs and DON’Ts’ section below before attempting to install the engine and then review again before attempting start the vehicle. Note that if the engine will not come off idle after the control system installation, check for an illuminated MIL (malfunction indicator light, which is located in the fuse/relay center, sometimes called the “Check Engine Light” or “Service Engine Soon” light) which indicates stored fault codes. Check for codes and make any required repairs if the MIL is illuminated (typically it is a connector issue or a wiring issue), consult a service manual if necessary (2015 Cadillac ATS).

[marksawatsky]

Thanks 2000Firehawk. I hope I can get my engine running without all that

[ATLsilverSS]

Marksawatsky if you get yours up and running please let me know what you did. Ive got a very similar car to yours that's an scca solo autocross car (e mod class) with a lnf motor and ecu currently tuned on e85 by trifecta. I am currently rebuilding the motor due to bad rod bearings from oil starvation (make sure your oil pan is baffled and/or has a better windage tray than the stock oil pan does). In addition to the rebuild we're doing upgrades to motor and chassis as well. When complete I would love to get the car running on hptuners. Trifecta is too slow and I want to be able to view data. Not to mention I can datalog with hptuners pro. It's next to impossible to log the car and trying to hold a laptop. Feel free to text me as I rarely get on these boards. 678-522-4597. Thanks, Chris.

[ATLsilverSS]

And I've seen harnesses similar to what firehawk posted but we are dropping almost 20k upgrading the car this off season and just can't see nor do we have another 2000-2500 for a wiring harness. We already have a harness we modified from a 09 cobalt as that the motor and whatnot came from. I just need to figure out how to get it running on hptuners.

[marksawatsky]

I'll let you know if I get it running. To be honest I'm less than impressed with everything right now. My engine with my wiring harness can be made to run with Trifecta but those guys keep charging more and more money when you want changes. HPT can't get my engine running so far and there have been few answers on this forum. You would think that with the collective knowledge on here, a forum search would reveal everything I need to know.

[sprinto7]

Is there anyone at HPTuners that is working on the LHU Stand alone/engine swap solution? I had a similar problem several years ago with an LNF (Now ATLsilverSS's problem) and at the time only Trifecta had a solution.
It would be a GREAT addition to HPTuners tunes.
There has to be some market for this.

Del Long

[TurboWood]

You should talk with Alfafabindustries. They use the LHU ECM + HPT for their kits. They are very proud of their wiring harness+ECM, but hopefully they will be willing to help you out.

Daniel

[marksawatsky]

And still, nobody can patch the VATS and get my engine to start.

[marksawatsky]

IT RUNS!!!! Video here: https://www.youtube.com/watch?v=OIniCs1Mr9U

[Bill@HPTuners]

Glad to hear it wasn't an issue on our end and that you got it started and running.

[ATLsilverSS]

IT RUNS!!!! Video here: https://www.youtube.com/watch?v=OIniCs1Mr9U

What was needed to get it to work? I'm ready to fire our one jeep up once the clutch arrives next week. I desperately want to get it off trifecta and on hptuners

[marksawatsky]

Ok, to bypass VATS, you have to take a regular Bosch relay, hook a wire from relay pin 85 to X1 pin 63 on ECM, and ground Bosch relay pin 86. Don't worry about Bosch pin 30 and 87, they don't need to be hooked up and mine are not. That's it. Here is the wiring diagram

[marksawatsky]

I put the car on the dyno today and everything went as smooth as glass. It made 282 HP before even touching the tune. Jerry from Bad News Racing used TeamViewer program to make the changes remotely on my laptop and I just loaded the tune and made another run. After a few runs it was making really good power and I didn't have to stress the engine at all. We didn't run it to risky RPM or even close to lean. We didn't run the big cooling fans on the car and it's temp stayed at a steady 185. I also took it for a drive and it really goes and feels amazing. My rear brakes are bigger than the fronts and even with full front bias, it tended to lock up rears. I have already solved this but milling away 1/3 of the rear brake pads. It's crude but it works. I'm going to source some higher octane fuel and will try again another time. Watch the video to see what the final numbers were.


https://www.youtube.com/watch?v=jbB3n2pGGFc

[Speedytec]

What ecm does this run? The E39 or the E39A?
And does it run a "special" stand alone layer tune a la Trifecta, or just a HPT tune suited for your car with all the non-present stuff turned off?

[marksawatsky]

E39A, Trifecta hasn't come anywhere near my car. It's a Bad News Racing tune

[BadCop]

Trifecta sux