I ran B+to pin 8 of main relay (ecu fuel pump over-ride?)

now checki engine light stays on and car won’t start. Any solid ideas? Blown diodes? ecu?

'93 1.8

curious… why did u do that? if anything u should’ve sent power to pin 4 or 6. not to 8. 8 goes to ecu as a ground.

http://www.tegger.com/hondafaq/mainrelayoperation/index.html

i think u basically fried ur ecu.

if u wanna test ur mfr… just solder it or replace it or borrow one. i highly suggest just resoldering ur existing one to save u money.

To many variables after having a series of problems, mind frazzle and not realizing the grounding function, my only car… stupidity…

I had just tried the resoldering of the mfr to no avail.

Great link, something to study.

Hmm, fuses… I picked up the B+ from pin one and the pin 8 takes ecu takes B+ anyway… so that damage to the ecu seems unlikely since it takes the B+ and either grounds or opens that circuit…

This link, http://www.tegger.com/hondafaq/mainrelayoperation/badmainrelay.html

covers relay starting problems Brilliantly/completely… covers many of the standard Hairpuller problems. Wish this kind of thing were o9n the top of the pile!

so did u find the issue or not cuz u seem to be speaking jibberish.

also pin is the ground… (someone correct me if i’m wrong)… prolly should ask fcm in the electrical forum but… if u put b+ to pin 8 which is only a ground… all you’re doing is creating a short… from positive to ground. pin 8 has no loads… it goes straight to ground. i’m basing this off of the basics of electricity. take a wire and connect it to the b+, then have that touch any ground on the vehicle whether it be an engine ground or body ground… you’ll see the results quite clearly. pin 8 has noooooo load. the ecu isn’t a load there.

In my understanding pin 8 goes to ecu which functions to ground it for 2 sec, then opens or lifts the ground. Pin 8 receives 12v during this 2 seconds, path:B+/relay sw/diode/dropping resistor with a connection to pin3 (to ecu) along the way and another to the starter signal. Also note that attaching a wire with a unloaded run to the battery to ground gives an instant spark ( which was not the case) And rather rapidly makes things smokey, melty and luminescent! The correspondant ecu pin must be less than a full ground.

Your link has been Extremely helpful. It’s been a while since I’ve had to do this kind of troubleshooting (BMWs and Volvos). II haven’t seen such excellant material on the web before, thought I have seen the Rover materials.

I haven’t talked to him but fcm seems a champ; kudos.

I’ll be looking at the car again in the next hour.

back to intermittant starts and runs and doesn’t. Runs for a few minutes… sometimes. Got spark and f pressure but needs starting ether to start. Off to investigate injector circuits.

… how bout this. replace or borrow a known good working mfr…then borrow an ecu or buy one. then go from there.

Yes, on the agenda…

I hooked up an led with a 300 ohm resistor across across a a pair of injector wires… power is there biut the light stays on while cranking. It looks like ecu but I’m suspicious of the wiring, not in the injector circuit itself but from whatever sends the pulse to activate them through the ecu. And I need to ge to a law library before monday! Damn.

[QUOTE=wblakesx;2042202]Yes, on the agenda…

I hooked up an led with a 300 ohm resistor across across a a pair of injector wires… power is there biut the light stays on while cranking. It looks like ecu but I’m suspicious of the wiring, not in the injector circuit itself but from whatever sends the pulse to activate them through the ecu. And I need to ge to a law library before monday! Damn.[/QUOTE]

i still think ur ecu is bad. cel is still staying on… seems a lil bright n easy

I bought an ecu at the pick apart but I hadn’t relised it was an auto and I have a manual so I ordered one from E BAy. But btw what sort of price should one pay if they have time to wait for a good deal?

i usually see them around $50. sometimes u can find some for $25.