RB25 CAS - Internal Short?

[Darius]

This is such f@#king BS! I was trying to start up my new Haltech system and I couldn't figure out why the coils weren't firing. I went through the wiring harness and the coil wiring was all correct (power, ground, and signal). I sent the ECU back to Haltech and they bench tested it. It tested out fine.

I started looking at the CAS because I wasn't getting any RPM signal when the motor was turning over via the starter. However, when the CAS is removed and spun in my hand, the injectors fire etc and I get an RPM signal.

Is it possible for the CAS to work when the body of it is not grounded and then fail to operate when the CAS is on the motor?

The car ran last fall when I put it away and winter mysteriously caused electrical gremlins?

[Carl H]

sounds more like a power routing problem honestly...how did you wire up the haltec?

[Darius]

I charged the battery over night because it finally died after priming the pump 100x and attempting to start another 25x. I think the CAS and ECU weren't getting enough voltage because the engine fired up and ran this morning. However, it is not firing coils 3 and 4 now, where previously it wasn't firing #2. That was the original reason I sent it into Haltech.

I checked the power to the ECU last night and it stays powered up when the key is in the start position. I also confirmed the CAS is receiving the same uninterrupted power source and it is. I even tried to hotwire it to double check and it wouldn't fire off. I'm confident in the power routing to the ECU because the PFC ran on it and I didn't change a thing. The only additional wiring I did around the ECU involved cleaning up some ground wiring but those still ground at the same spot next to the ECU that they did before.

[Darius]

Haltech is thinking it is insufficient grounding between the front and rear of the car since my battery is relocated to the trunk.

[Darius]

I ran a #4 wire between the battery ground at the trunk and the location where I ground the coils and engine block. Problem solved!

[RRRRB]

awesome, i had a simular problem with my honda years back... wouldnt run it cranked all day but just wouldnt fire... no grounds from chassis to engine was the problem...

Glad you figured it out... whens this thing going on the dyno for some race gas and lots of boost?

[Darius]

I have been learning Haltech's software this weekend and basically got it to cold start, hot start and idle properly. LOL Baby steps! Now, it drives fine as long as I stay out of boost. Otherwise, it goes instantly lean and it will knock. I just did my first log with it yesterday so I'm trying to figure out how to tune it compared to how I tuned with datalogit.

[Coolwhip]

Glad you got it sorted out Matt... and getting to play with the software. In for the results!

[robbie2883]

matt, which haltech are you using? pnp pro platnium? you should be able to just setup the VE table and get her boosting good

[Darius]

Yep platinum pro. What do you mean by setting up the VE table? I loaded their base map for the RB25, but as soon as it starts hitting boost, it goes lean. I'm controlling the fuel pump speed at low TPS and RPM. It might be sped too low for slow ramp up into boost.

Besides that, my VE table corrections at idle are so far from the base values that I'm not sure that I have the lag and injector firing angle set correctly. I feel like I tweaked them so it will work, but I am not entirely confident that I went about it the right way.

[Carl H]

run the pump at max speed...variable only seems to cause problems.

[Darius]

Carl you are right on!I figured it out about an hour ago. I had the pulsed signal settings backwards in the table so instead of 100 being 100% duty, it means the exact opposite (0%). So I inverted my table values and it revs well into boost rich as ever! (AFR=10-11)

Next on the list is to burn all of this 93 pump fuel off and fill up with summer blend E85!

[Coolwhip]

In for the Dyno numbers

[Carl H]

i say 673 alpaca/furlongs.
at the wheels.

[Darius]

I'd be happy with that although I'm shooting for 700 at the wheels.

[Carl H]

what is that in alpaca/furlongs?

[Darius]

In international units, it is bovine/rod and I'm hoping for 11,420.