ECU issue - Forgetting Tune, Lost 120hp with better turbo, fuel pump going crazy

s300 and SManager software questions & answers
Post Reply
Totsie7944
Posts: 1
Joined: Sun Jul 21, 2019 6:58 pm

ECU issue - Forgetting Tune, Lost 120hp with better turbo, fuel pump going crazy

Post by Totsie7944 » Sun Jul 21, 2019 7:16 pm

Hey all

**Cliff Notes - 3 issues, ALL of which others have posted about on this forum- 1) Significant power loss 2) Intermittent power loss on track 4-5 years ago and 3) fuel pump bouncing around. I took my ECU to a guy in CT who can repair P28's and also was able to get me a brand new OEM S300 installed. He noticed my ECU had 3 capacitors that were bad, and also 2 runways (copper) that was destroyed. Could my ECU have been the cause for all?***

I have a 2000 Integra Type R w/ a full-race AC Turbo kit and originally had the GT35R turbo. The car made 550 whp on 93 octane pump gas (600 whp w/ Meth). i used to track the car. And about 5 years ago I was at VIR and the car would suddenly lose power or be way down on power after coming out of a corner. I hadn't overheated or hit a boost cut. I would just drop the car into neutral and rev it up a bit, and then BOOM, power suddenly came back. I didn't think much of it, though it did happen a few more times. For the last 4-5 years I haven't tracked it, and the car has mostly sat.

That issue, combined with the 2 issues below I have found threads on this site about, so it seems like it likely is my ECU causing all of my issues. But keep reading....

I recently "restored" the car and felt a bit of shaft play on my GT35R, so I ordered the GTX35R while the engine was out. I also removed my old Skunk 2 Pro 1 cams, with new Skunk 2 Pro 1 cams (same cams). Same tuner, same dyno.

So, only thing touched on the engine was the turbo as far as a real change. I have been back to Jeff Evans twice now this spring/summer trying to figure out what's wrong with my car.

The first dyno session, it seemed like the turbo just wasn't responding/building boost like it should have. Jeff had to keep cranking up the duty cycle more than he thought he should need to in order to raise the boost to just 18 PSI.

We side by sided today's tune with my tune 10 years ago and both tunes were around 18-19 PSI. Old tune my 550 (600 w/ Meth) whp all the way to 9,000 rpm. Tune this year made 480 whp to only 8,700 rpm.

We checked boost solenoid - was working - we could hear it clicking, and we checked the vacuum lines to make sure were good.
Compression test was 180, 180 177, 177
9:1 compression in engine
Good spark

I then brought the car home, found a small boost leak, so I fixed that. Went back for another tune, this time only made 475 whp, and then other issues started happening. My car would randomly shut off on the dyno. And then the fuel pressure gauge and pump would start freaking out - like cutting in and out. We swapped relays, wasn't the issue. Then Jeff noticed it seemed like the ECU was forgetting the tune b/c the software would be gone, he'd had to re-upload the tune and then it would re-start. But, it kept happening over and over again.

So, I took my ECU to a guy in CT who can repair P28's and also was able to get me a brand new OEM S300 installed. He noticed my ECU had 3 capacitors that were bad, and also 2 runways (copper) that was destroyed.

He fixed my P28 with new capacitors, re-traced where the copper was missing with some fresh solder, and he installed a new S300 for me.

So my 3 issues, ALL of which others have posted about on this forum- 1) Significant power loss 2) Intermittent power loss on track 4-5 years ago and 3) fuel pump bouncing around.

I have yet to re-tune, but I'm curious if the Hondata reps on here can clarify if this all sounds like an Hondata issue given the V1's are notorious for forgetting tunes (had a recall I thought?) and mine is 10+ years old so the battery was likely dead. Could this have been the reason for such a big power loss, despite a smooth dyno plot once he was able to get a couple runs in?

I've checked everything else. Flex section looks brand new. Wastegate diaphragm and spring were good, fixed a boost leak, grounds are good and Jeff said I had good spark while on the dyno, no exhaust leaks.

Thanks!

User avatar
Hondata
Site Admin
Posts: 8726
Joined: Thu Aug 15, 2002 12:13 pm
Location: Torrance, CA
Contact:

Re: ECU issue - Forgetting Tune, Lost 120hp with better turbo, fuel pump going crazy

Post by Hondata » Sun Jul 21, 2019 7:55 pm

Well, you'll find out if the s300 was the cause, but that would not give intermittent cut outs, burn tracks or switch off the fuel pump. I would remove and clean all grounds but also consider that the wiring harnesses in race cars fatigue over time and that might be the problem. Also datalog the battery voltage and check it is steady.
Hondata

Post Reply