Ok folks need dome more help. I got a few people helping me right now, like J and nikita. We are trying to figure out of the OBD-0 to OBD-1 conversion harness is the same for Civics/CRXs and 3rd gen Ludes. Someone said they think they are different. But I need to know before I buy one. Thanx in advance.

 

OBD0-1 looks very similar/same for the 3G prelude. I've compared it to my personal OBD0-1 conversion guide (which actually works and isn't missing pinouts like every other one I've seen, and is designed for use with USDM OBD1 ECUs and not the ****** JDM P08/P30 with half the sensors missing/unused)

Here are the differences, according to the online wiring diagram slipslap PMed me:

OBD0 B1 = compressor control unit (??) on 3G Prelude, is normally constant power in on PM6, goes to DTC memory for clearing codes... hazard fuse, you dolt!

OBD0 B5 = ign timing connector on Prelude, Alternator connection on PM6 ECU, and OBD0 VTEC signal on PR3/PW0. AFAIK, doesn't hurt to leave disconnected with a PM6.

OBD0 B19 = automatic control unit on prelude, is P/S pressure switch *and* ELD on 90-91 LS, just ELD on PM6. Yup, 90-91 PR4 seems to bump up idle under high EL.

Unused:

OBD0 C8 = EGR lift sensor. This is one of the exceedingly homosexual wires that has to be removed from LS swaps into CRX HF's, as it leads to false code 14 (PA sensor). I'd remove the pin and tape it to the side.

OBD0 B11 = 2nd O2 sensor. News to me that the 3G Lude has a second O2, but I don't touch them much.


Everything else looks identical, and I have plugged a 90 Prelude PK2 ECU into my LS powered HF in the past... idled and revved fine (never went on test drive) but kicked EGR code since I lack that shizzle, fo' rizzle. I say Civic based OBD0-1 conversion harnesses will work with a touch of finesse from the Prelude owners.

 

So I can buy the Civic conversion harness and I will be good? Cause i don't have EGR either. If thats what your telling me, that means I'm starting to take a step inside the house of boost. You da man, if we straight!

The O2 deal is the OBDo ones of course. We have 2 single wire sensors. I have already converted to a 4 wire heated sensor long ago. But the 90-91 ludes with the B21 had the OBD1 harness and the 4 wire sensor already.

 

You have the B21A1 engine? I thought someone claimed that those had OBD1 ECU plugs?

 

I have the B20A, my car came with the B20A5 so it is OBD0. The 90-91 with b21A1 did have the OBD1 plugs. I changed my O2 sensor top a 4 wire sensor cause I used a B21A1 DC header. Who would you buy a harness from? I have looked at Boomslang, JDmShit and jkob something.

 

I really have no preferrence, but I hung out on the old Hybrid forum with Newmann who owns JDMshit.com a couple years back. I never talked to him or anything, but he always seemed like a nice guy. "Better the devil you know," and all that.

 

he had a better price and his looks good in the pic. I was trying to get them to hook me up with a deal. They don't have hardly any 3rd gen ludes with them. I told them I would test and relay how it works and if any problems. But I don't think any of them are going for it I think I am gonna go with the JDMShit though. And then a PR4 ECU. I just got me soem 450cc injectors for $20 from a guy. And I found a place to make my exhuast flange for $60. Sound like a good price?

Oh yeah, what about this foru member? Are nikitad's hranesses any good? he offered me a lower price deal. But I think he uses used parts to make his.

 

Not really any new updates. I got my injectors and a PR4 ecu and getting my harness next. I found a Willems burner that gets power from a USB cord. It comes with the USb cord and the data cable and cd for the software for $44 shipped. Is that a good price and a good burner? If so I will get it. Then it's on to the actual turbo goodies.

 

Dang folks lose interest in helping me trying to squash my boost dreams? I guess i will have to continue on my own.

 

Uhm, sorry, I've been working a lot lately and haven't seen the thread in the top 2 pages.

I have no preferrence over new vs used harnesses. I've yet to have one I constructed out of used parts give me a problem. nikitad from all I've seen seems to be a reputable HT member. Dunno how that helps you at this point.

Dunno how the Willem's USB works, but the moates.net USB burner can't draw enough power to burn 27Cxxx series chips, it does 29Cxxx only. You'd find 29C easier since they erase on the fly instead of needing a UV-C light, but I like flexability in my equipment. I do a lot more than just Honda ECUs with it.

Get your ECU/burner/harness together and get your Lude running off it, then go onto the boost.

 

That is my plan. I'm gonna get that and put it in my car and see how she runs. And maybe mess around with Uberdata tweaking the ECU for NA purposes to try and get a grasp on it. And see how I do. While at the same time build my manifold an ddownpipe and charge pipes. And once I get a grip on it, slap on there and head to the dyno.