wagon burner

Hello, Im new here and cant find any info about my problem. I was driving my car then it just died. I thought the feul pump went out. Found out not the problem, read about the relay but I dont think this is my proble either. When I turn my key on the pgm fi light does not light up. I dont find any bad fuses.... I looked at the computer thing under the seat and it looked toasted, I think it got wet or something. I have an 85 si with all the parts but dont think it can be swaped out. I find the plugs mount up diffrent. On the one from my '87 the plugs go biggest to smallest. the other one, puts the smaller one in the middle..... any ideas????

cbstd

Honda changed all the electrical connectors in 1986, so '85 stuff will not plug into a '87 in most cases.

Your issue could be something simple like a main relay or an ignition switch.

wagon burner

I hope so. But still really looking at the what I'll call the cars brain, it has rust and what looks like mold on it. I am currently looking for another parts car, and getting a new relay for it. Hopefully I'll get my rex back on the road soon!!!

wagon burner

Now I was wondering I am looking for a 1986 through what year for my parts? I now know that my car has brain problems. Help I want my car back!!!

JDMCIVICMAN1992

86-87 Si's are interchangeable. A good portion of the '85 Si can be used as well.

wagon burner

Mainly looking for computer parts. Will parts from a Dx, or Hf work just as long as it is feul injucted and has the correct plug set ups? Im confused on when computer components changed in these cars.... Should I just look at all honda CRX's and Civic's I find???? I wanna go

wagon burner

Ok I have been in contact with diffrent wrecking yards, and a few honda dealers. I am getting diffrent responses to my problems. Ok once again my 1987 honda died. I have an 85 parts car. Both are SI, but the ecu out of them are diffrent. The dealership tells me that they are both the same, just plug diffrence. One wrecking yard says the 85 wont work, another says it will.
But here is some info I've been told I could use a ecu form a 1986-1987 Civic Si, or 1985-1987 Crx Si.
Now here is the numbers on my ecu I have a 37820-PE7-6820 I have been told that a 37820-PE7-6920 superscedes the one from my car?
Now I have an Idea, with the plug diffrence in the ecu's, (both 3 plugs, just moves plug location.) could I just fix my harness in the 87 to match the 85?
I am starting to miss my suburban..... So much easier, imports confuse me!!!

wagon burner

Ok I found an ecu. Found out any "PE7" will work. Still nothing. Have tried a few diffrent Main Relays, still nothing. Thinking its in my wires but not sure where to look first. Any ideas? Still have no fuel pump power or pgmfi light on the dash. Things are getting closer to having a running car again but still so far!! Oh and I looked at my plugs for the ecu and found out there is no diffrence in plugs..... Must have had one too many beers!!! Lol.

wagon burner

Well crap, I have found burn wires at the ecu, at the main relay on down to the dang fuel pump...... I have the 85 si but I dont think all the time and energy spent are worth it. Im about to nuke that dang car!!!!

wagon burner

Ok well have not nuked it yet. With nothing better to do I'm still messing with it. I pulled out the carpet and all the fun stuff. I cleaned up the connectors and now have continuity through out them. But still no pgm fi light. Now I'm trying to figure out if its my ignition. How would I check this? By looking at it if the tumblers were to break I dont have any way of taking it out without some kind of car operation. No screws just some rivets. Is there a way to test the ignition? Starting to wish I lived around someone who knew hondas. Any help on ideas would be greatly appreciated. I have been out of my own ideas but just keep messing around and am hoping I am close.

wagon burner

Oh yeah and is there any difference in main relays in the crx's other than the plugs being different? Could I break off the locking mechanism on one thats different to test if it is just the main relay? I have looked online and found how to repair them but they all seem to operate the same just looks like they mount up differently. Same wires go to same places but like I said just different "mounts".

wagon burner

ok ive created a continuity tester with my battery, some extra wire for conection, and a test light. I've been poking around and found all wires i've test to be good. Ok here is where I start getting confused, with the main relay in when I turn the key I get the "1st" click but no feul pump or ecu light. Im guessing no 2nd click because of no ecu? and the 3rd just before the starter engauges. Now I'm thinking I have power up to the main relay just not after. I've taken out the main relay and the ground tests good, but still am trying to trace the other wires to find where they go. So after all this, is it just a case of trying a few diffrent bad relays?

profs77

I know whats going on. You should have around 3 lights light up when you turn the ignition to on. PGM-FI should light up for about 2 seconds, this means that the fuel pump has pumped some gas. Your seat belt warning light should come on, and I guess thats it. If the PGM-FI light is not lighting up when you turn it on, that means that the ground connection from the battery is not connected properly. Unscrew them, clean the connections and connect it back. Corrosion or rust could be the cause. There is a fat ground cable that bolts on to your transmission. If its on loose, or bad, enough current can flow through it to power **** like your radio maybe, but not good enough to power things like the starter motor or fuel pump.

wagon burner

Ok, I have tested, and tested, and tested some more...... Still nothing..... Now I came up with an idea and removed the ecu, main relay, and ignition wires and put them into my 1986 honda crx (my third crx.) The car fired right up..... The stuff out of the 86 went into the 87 and still nothing. The only diffrence in the cars I find is the ecu, the are both a PE7, but they have diffrent ending numbers??? Would this make a diffrence? Ok let me back up. I came across another crx (parts car) but the ECU and Main Relay were diffrent numbers. The only diffrence in the main relay was the locking part on the plug. I broke it off and pluged it in everything works the same from what I find. And still confused about the ECU.... I keep getting diffrent info with ECU's some say any PE7 will work and some say everything must match????? WTF!!!???

profs77

Did you check that ground cable I told you about?

wagon burner

yeah I have checked it. I tested for contunituity in the ground from the main relay plug to a known good ground and also the ignition switch. And I took off the ground cable from the battery and cleaned it up, as well as all ground straps I can find....... Im thinking its somewhere between the main relays "power outs" or maybe the main relay is not getting power from all locations. I need to get a real tester before I think I can go from there. But I am still looking for wiring diagrams for my car, so I need to go buy a book for it as well.

wagon burner

Ok have not been here in a few but the problem was simply the number 4 fuse! I feel like a dumb ***..... i bought a haynes book and they suck, did not mention that fuse even related to the main relay. I found a free chilton site and found a very good picture of my wiring harness. Problem solved!!! Big head ache for nothing.

tiedyedpunk

Wow, you got lucky, sort of. I'm not too good with electronics, but when my car breaks I always look at the fuses first. So was it the fuse or the wiring for the fuse?

tiedyedpunk

So my 87 civic SI just died while driving down the road. I know nothing about electronics, but I have a multi-meter as well as a continuity tester and downloaded some manuals. I've been tinkering around a bit, but this is such a complicated process I thought I'd look online for threads like this one. I know this thread is old, but I thought it'd be better to add to an old one rather than start a new one. Anyway. At first my PGM-FI warning light would light for 2 seconds, then go away, no lights on the ECU showed. Now the PGM-FI warning light comes on and stays on, again no ECU lights. Any ideas what could be causing this?

As far as trouble shooting, I can't bring my car to a shop because it won't run, and even if I could, I am currently unemployed and broke, so a mobile mechanic is also not an option. The manual says to use a "System Checker Harness". Do I need this, or can I just do my testing with a multimeter and a continuity tester? So far I've been doing it like this, but I wanted to know if my results are incorrect because I'm not using the "SCH".

So the troubleshooting guide begins with:
(11-12 of the service repair manual)
"If the LED display fails to come on when the ignition switch is turned on again, check for:
- Blown No. 1 0 fuse (Shows continuity when I check).
- Open circuit in White/Green wire between ECU A17 terminal and No. 10 fuse. (Also shows continuity when I check).
Then, if there is no problem, substitute a known-good ECU and re~check.
(Ok, so now they want me to get another ECU. But I really don't want to buy another ECU because there could be another cause of this).

HELP!