HKE LSX 427 with D1SC is in!!! but WTFO?
 

Alright. Need some brainstorming here. Spent the last 2 days with my car down at SNL Performance. The motor is in, the Aeromotive eliminator, billet controller, return style fuel system is in a wired correctly. (Aeromotive needs to get their shit together in this respect!!!) Pump runs at low voltage until 5000rpm then kicks into high gear thru the speed controller.

All this went fine. We did the initial drivability tune (Pat Guerra is the tuner) about the best there is...google him!!

This was done thurday PM. Friday morning we figured out that a relay was required for the 16 gauge power wire to the FPSC. Without the relay the pump would fire up at key on, but the rail pressure would drop from 58 to 0 as soon as the motor started to crank. Basically, voltage at the FPSC would fall below 10.5 which we determined was necessary to power the FPSC. A relay fixed this problem and all was good with all the Aeromotive....the pump is loud, sounds like an ass ton of Africanized killer bees are in the back seat. (the back seat was not installed however.)

So heres the deal. Dyno runs went well. Pat G tuned it without the meth pump on and was conservative. We had major belt slip on the D1 at about 5300 rpm where the best run peaked at 690RWHP and 684RWTQ. This all happened at 5300 rpm then the curves went flat to 7000. I watched the boost gauge int he a pillar peak around 11-12 psi and fall flat at this point as the rpm climbed to 7000. You could smell the rubber belt burning.

I was pretty happy with 684RWTQ at 5300 and knew i could always upgrade to a 12 rib later. Oh BTW the MAP sensor is the stock 1 bar.

Pat G wanted to go for a final streetability drive with my driving.

First time i got on it, major TQ kicks in in 3rd....feather the throttle to get back in control then back on it to about 5000rpm. Then "reduced engine power" kills power and P0606 code is present. "PCM internal fault" is what this is. Pat has never seen this. He clears it and i try again...same result but at a little diff rpm. He clears it and again, same thing when getting on throttle.

Pat disables the code and we try again, but same result but no code is reported since he disable it.

We spent hours on this, he reset the entire pcm, reflashed the tune, i pulled PCM circuit breakes, we check grounds and the PCM harness at the connectors and all look good. Take it out again and same thing. it would "reduce engine power about 2 out of every 3 times when giving it gas.


Anyone out here seen this type of thing?

Plan is to bypass the Aeromotive speed contorller and run the pump full speed to see if its a contorller issue.

If that does not work, i want to get a new PCM and reload Pats tune and start with a fresh computer.

I think maybe my OE pcm just went tango uniform (tits up) when we deleted the OE fuel control computer when we went return style????

Lots of smart guys with lots of experience were consulted and all just scratched their heads and went "Hmmmmmm"

You mentioned both of my ideas. Disable the pump controller and try a fresh PCM. The code "internal fault" has bad PCM all over it. But, once you're passing the 700rwhp mark you're kind of wondering past its capabilites and it might be time to look into a stand alone unit anyway.

Are you running a stock throttlebody?

Good luck finding a solution.

Welcome to the world of getting a blower belt to work. This is why I wish I went turbo. I just swapped belts again hoping to get one to work. I may have to swap crank pulleys again to get it to work.

Yes, but the ported revexteme unit. That is one of the first things we swapped out. they had another LS3 unit on the shelf. Same result.

This same TB worked fine on my old motor at 715rwhp and 611 tQ.

Yes we are at a pretty hefty torque of 684 at only 5300rpm but Pat has seen much bigger power with the same TB and no issues.

It would have also kick out a different code. Pat has never seen the P0606. It basically tells me the computer/pcm has had enough and given up. I unplugged teh battery before leaving and SNL will look again next week

ive seen this happen first hand two days ago on three different cars with nick williams 102, but those were with PD blowers.

I hear ya Nick. thing is, the car was ridiculous as soon as i would even start to get in the gas. i would have to feather the pedal to keep it straight. Then as things were starting to go real nice, the car would surge forward and the reduced engine power would take over!

I will go 12 rib once we figure this out but see no reason to add any more torque to this thing. Its pretty stupid as it is at only 5300rpm:D

Seen what, the p0606 code (PCM internal fault)?

One other thing comes to mind. On thursday evening when first tryng to start teh car with the fuel system wired. I had a dead battery. We hooked up the big charger and tried again. This is when we first figured out that fuel pressure would drop from 58 to 0 at motor crank.

We were assuming weak battery since voltage at speed controller would drop from 12 to about 8.2, so speed controller not activating pump under motor start.

They cranked up the charge to the battery from the charger...it was a pretty big charger btw. Basically went to the engine start position and used that mode to charge the battery for a while.


Could this have spiked the PCM logic

Is a direct drive available for you camaro guys? I know Dallas Performance makes a nice unit for the Vette's. Once you get the belt issues sorted out that thing will make some serious power to the point of maxing that blower out. What are you revving it to? I've heard nothing but bad things about Aeromotive lately and that is enough for me to go in another direction when I do my build.

Jim,

We had a similar problem with our shop car after installing our new motor.
It kept going into limp mode and throwing that code any time you would start it and try to give it any gas.
Turned out it was a wire that had come loose at the PCM plug. Cant remember if the wire was just pulled out or it was cut but after we fixed it, everything was fine.

Jim,

I didnt follow all of it and I'm trying to remember all the details from my Aeromotive install...

Here was part of the situation...

Key on, pump would run up to fuel pressure, 58-60 psi... Turn the key to start and the fuel pressure would drop off to zero...

This was a case of when the key was in the start position, the (hope this is correct) BCM was blocking power to the pump along with most other electrical components and so the pump wasn't running... Hence, fuel pressure drop off and not enough to start the car...it's redirecting power to the starter...

The fix was to roll the key to the start position and immediately let off... It'll still run the starter for a few seconds, and the power is allowed back to the pump so it maintains pressure and the car would start... Contrary to old rules, these car will continue to crank for, if I remember correctly, as much as five seconds after releasing the key if you just bump it to start and let off to the run position...

I never had a problem starting it after that...

As for the other issues...

I never threw any codes, but occasionally when going from cruise to WOT, I would get a fuel pressure spike and the car would surge and buck really hard.... We never figured that one out as the Aeromotive crapped itself prior to us diagnosing it....

We pulled the junk pump and the billet FPSC out and put the Lingenfelter dual pumps back in the bucket, built a surge tank and installed an external Weldon fuel pump... No issues at all since... Aeromotive couldn't understand why I didn't want their pump in my car anymore... Must have been something about it only lasting seven hours total...

The dual pumps feed the surge tank running wide open with no back pressure all the time, and the Weldon pulls from the surge tank... 2.5 gallon, and feeds the rails via a fuel pressure regulator....

Oh, we had the Aeromotive set up on a hob switch... At one lb of boost it went from low to high speed mode...

I'll check with Corey, but there was something about bypassing the PCM and then having the trick it into thinking the factory fuel pump was there so the car would run right.

Again, I don't remember all of the details, but I'll see what I can find out...

Camaros already use a "direct drive" for all their blower kits. Only vettes use the same belt. Procharger, Vortech, ECS, etc all run off their own blower belt.

Stock TB is fine, stock ECU is fine (assuming it isn't broken). 1000-1100rwhp is done all the time with them. I think you are on the correct path.

What area of Texas are you in?

Robert, for the starting issue, we had the identical thing. turn key to power on pump, fuel pressure was 58. Go to crank car and it would drop to zero. Our solution was to wire in a relay to the red 16 gauge power wire to the controller and that fixed it.

It was perfect on the numerous dyno runs, just major belt slip at 53-5500rpm.

ON the final street tune the PCM started acting up and giving us the PCM internal fault code with reduced power.

We are gonna bypass the aeromotive controller and dyno it and see it it kicks out the code there then take it out on the street. It it doesnt kick out the P0606 code then we isolated that the aeromotive controller is the issue and conflicting with the pcm.

It that does not solve it and we still get the pcm fault i am leaning to changing out the pcm. One last thing i want to do is unplug the connectors to the PCM and check all the wiring there.