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Author Topic: ECU in the engine bay?!?!  (Read 1802 times)

Offline Skeeter

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ECU in the engine bay?!?!
« on: 07:24:35 PM / 19-Nov-15 »
I'm playing around with the idea of sticking my ECU for my KA in the engine bay behind the LH headlight, where the air box would be. I know these ECUs normally go inside the car and since it's not technically sealed, can accumulate moisture/dirt/etc. inside. But what if I seal the case up? Anyone see a problem with this? I know it's probably just a wishful thinking pipe dream.

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93 S13 HICAS - redtop SR, FMIC, Nur-Spec catback, 12psi, untuned, 13.8@98 PARTED AND SCRAPPED
02 WRX - full exhaust, intake, 17psi 13.3@100 SOLD AND THEN TOTALED
91 S13 - redtop SR, CP 9.0 pistons, HKS 264 Step 2 cams, Eagle Rods, Fidanza valvetrain/flywheel, Spec Stg. 3+ clutch, FMIC, welded diff, custom fire wire, 14.7@107  BURNED AND GONE
05 G35 - white, tan leather, RAYS, sexy REPO'D
03 ZX-6R 636 - traded for truck
96 Sierra - 305, 2wd, Cragar D 17's, flowmaster SOLD
89 240sx - bought to flip SOLD
87 200sx - daily KA swapped, still repairing LITTLE BY LITTLE

Offline rednucleus

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Re: ECU in the engine bay?!?!
« Reply #1 on: 07:30:28 PM / 19-Nov-15 »
I would not be comfortable with my ECU under the hood. Keep it inside in a relatively clean dry controlled environment.  Sealing it up may also cause heat related issues, and temperature swings may lead to condensation corrosion issues. After working on my circuit board recently, I'll bet it would turn in o a corroded mess under my hood.

Offline iceageg

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Re: ECU in the engine bay?!?!
« Reply #2 on: 11:34:26 AM / 20-Nov-15 »
I think red hit the nail on the head.  If you wanted an easy way to disconnect it you could always get a high quality multi-pin bulkhead connector and place it in the firewall.  Then you could just unplug the whole harness from the inside or outside as needed.  It would be a fair amount of work that would probably only pay off during the rare engine swap but i think it is a better solution than anywhere under the hood.
I was afraid all the five gallon buckets of pain stacked four high were going to fall over

Offline sideways_s12

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Re: ECU in the engine bay?!?!
« Reply #3 on: 02:44:02 PM / 22-Nov-15 »
I also agree with Red I think it's an all around bad Idea. The factory put the ecu inside the car for a reason...

Offline Skeeter

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Re: ECU in the engine bay?!?!
« Reply #4 on: 11:38:34 PM / 22-Nov-15 »
Engineers aren't always right. I do understand they're not really designed for it, I just got bored and wanted to think outside the box a little bit. As a side note, my swap is almost done lol.
93 S13 HICAS - redtop SR, FMIC, Nur-Spec catback, 12psi, untuned, 13.8@98 PARTED AND SCRAPPED
02 WRX - full exhaust, intake, 17psi 13.3@100 SOLD AND THEN TOTALED
91 S13 - redtop SR, CP 9.0 pistons, HKS 264 Step 2 cams, Eagle Rods, Fidanza valvetrain/flywheel, Spec Stg. 3+ clutch, FMIC, welded diff, custom fire wire, 14.7@107  BURNED AND GONE
05 G35 - white, tan leather, RAYS, sexy REPO'D
03 ZX-6R 636 - traded for truck
96 Sierra - 305, 2wd, Cragar D 17's, flowmaster SOLD
89 240sx - bought to flip SOLD
87 200sx - daily KA swapped, still repairing LITTLE BY LITTLE

Offline JonB

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Re: ECU in the engine bay?!?!
« Reply #5 on: 05:21:09 AM / 23-Nov-15 »
I pulled one ecu from a yard and water had gotten in it - one of the boards was warped. If you open one up, you can see that there's a series of transistors mourned to a heat sink - it is a computer, but I don't know that it gets anywhere near laptop hot.

On the other hand, I don't think my megasquirt has any cooling vents or openings. If you have a few ka units, and keep the car outta the rain....

Offline sideways_s12

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Re: ECU in the engine bay?!?!
« Reply #6 on: 12:39:48 PM / 23-Nov-15 »
True engineers aren't always right but they are right in most instances otherwise they wouldn't be engineers lol anyway how much more is left with your swap?

Offline Skeeter

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Re: ECU in the engine bay?!?!
« Reply #7 on: 08:58:20 PM / 24-Nov-15 »
I still have to finish up the wiring a bit and figure out why my trans mount isn't lining up. It wants to sit hard left and about 1/2" too far back. I've done a lot the last couple weeks and chipping away at my to-do list. I have a bunch of tedious cleaning and such left, but I want to hear it purr.
93 S13 HICAS - redtop SR, FMIC, Nur-Spec catback, 12psi, untuned, 13.8@98 PARTED AND SCRAPPED
02 WRX - full exhaust, intake, 17psi 13.3@100 SOLD AND THEN TOTALED
91 S13 - redtop SR, CP 9.0 pistons, HKS 264 Step 2 cams, Eagle Rods, Fidanza valvetrain/flywheel, Spec Stg. 3+ clutch, FMIC, welded diff, custom fire wire, 14.7@107  BURNED AND GONE
05 G35 - white, tan leather, RAYS, sexy REPO'D
03 ZX-6R 636 - traded for truck
96 Sierra - 305, 2wd, Cragar D 17's, flowmaster SOLD
89 240sx - bought to flip SOLD
87 200sx - daily KA swapped, still repairing LITTLE BY LITTLE

Offline sideways_s12

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Re: ECU in the engine bay?!?!
« Reply #8 on: 11:37:38 AM / 25-Nov-15 »
Not to bad, before you know it you'll be done and driving her....

Offline iceageg

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Re: ECU in the engine bay?!?!
« Reply #9 on: 02:00:15 PM / 25-Nov-15 »
Engineers aren't always right. I do understand they're not really designed for it, I just got bored and wanted to think outside the box a little bit. As a side note, my swap is almost done lol.
My idea with the bulkhead fitting to quick disconnect the harness at the firewall is a little outside the box.  A lot more work but it definitely fits your outside the box criteria.
I was afraid all the five gallon buckets of pain stacked four high were going to fall over

Offline JonB

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Re: ECU in the engine bay?!?!
« Reply #10 on: 05:26:19 PM / 25-Nov-15 »
I was also thinking about trouble with the obd on this. You'll need two people to run codes.

Offline Skeeter

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Re: ECU in the engine bay?!?!
« Reply #11 on: 10:09:36 PM / 25-Nov-15 »
Well, I have an OBD2 KA and I'll be running a connector to read codes easier.
93 S13 HICAS - redtop SR, FMIC, Nur-Spec catback, 12psi, untuned, 13.8@98 PARTED AND SCRAPPED
02 WRX - full exhaust, intake, 17psi 13.3@100 SOLD AND THEN TOTALED
91 S13 - redtop SR, CP 9.0 pistons, HKS 264 Step 2 cams, Eagle Rods, Fidanza valvetrain/flywheel, Spec Stg. 3+ clutch, FMIC, welded diff, custom fire wire, 14.7@107  BURNED AND GONE
05 G35 - white, tan leather, RAYS, sexy REPO'D
03 ZX-6R 636 - traded for truck
96 Sierra - 305, 2wd, Cragar D 17's, flowmaster SOLD
89 240sx - bought to flip SOLD
87 200sx - daily KA swapped, still repairing LITTLE BY LITTLE

Offline Skeeter

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Re: ECU in the engine bay?!?!
« Reply #12 on: 08:22:46 PM / 05-Dec-15 »
Update: trans mount finished. Wiring is almost done, but while I was testing my starter connections, my head gasket decided to shit the bed. I'm glad that KA's are simple and that I wasn't driving it yet.
93 S13 HICAS - redtop SR, FMIC, Nur-Spec catback, 12psi, untuned, 13.8@98 PARTED AND SCRAPPED
02 WRX - full exhaust, intake, 17psi 13.3@100 SOLD AND THEN TOTALED
91 S13 - redtop SR, CP 9.0 pistons, HKS 264 Step 2 cams, Eagle Rods, Fidanza valvetrain/flywheel, Spec Stg. 3+ clutch, FMIC, welded diff, custom fire wire, 14.7@107  BURNED AND GONE
05 G35 - white, tan leather, RAYS, sexy REPO'D
03 ZX-6R 636 - traded for truck
96 Sierra - 305, 2wd, Cragar D 17's, flowmaster SOLD
89 240sx - bought to flip SOLD
87 200sx - daily KA swapped, still repairing LITTLE BY LITTLE

Offline sideways_s12

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Re: ECU in the engine bay?!?!
« Reply #13 on: 12:43:33 PM / 13-Feb-16 »
well that's shitty...