Hesstopher

First: not flooded.
Second: died on track, initial diagnosis led me to fuel pump relay which was bad. One is on the way to me should be in by Friday.
Third: I am concerned because my coil packs are not giving any power to the plugs.

While the relay was out I was doing some exhaust work and wanted to hear the car with open headers, just for fun. So I direct wired the fuel pump up and cranked it... nothing. I verified the pump was operating by listening to it, feeling the pressure on the feed line at the engine, and checked the return line for pressure.

I figured with cranking it without the pump running took a lot of the fuel out of the lines (like running out of fuel) so I kept trying, ran the battery down. Recharged it and tried a few more times. I checked the coil pack with a volt meter set to 500 amp (positive where plug wire connects, negative to engine block), cranked it-- no voltage.

Where I am now: there are a couple possibilities from what I see...
> there is a safety fault setup with the pump relay-- bad or missing the car won't start/run. (anyone verify this?)
> there is another relay that failed at/near same time which controls the coil packs. (anyone know of one, or where it would be?)
> there is a short which took out my fuel pump relay AND coil packs (or fuse/relay for them).

Any and all help is appreciated.

satch

iTrader: (1)

Engine fuse good? If either coil had voltage w/key to on at the B/Y wire then the fuse is good.

Hesstopher

the fuses near the battery are good. I checked the small wires that screw into the coil packs (coming from wire harness) those are steady on with ignition at "on" setting. They only have like 0.09v thought, my assumption is that is a signal from computer to send voltage to plugs and not the 12v power supply for the coil packs coming from the harness. Given the power those plugs draw I'd think they'd pull straight from battery or at least have a dedicated fuse/relay apart from the main harness to get that load off the rest of the system.

If someone can tell me what the normal voltage reading is on the coil pack where the wire harness connects I'd appreciate it.

satch

iTrader: (1)

Engine fuse is 15 amps and located in the interior fusebox. It powers the Main Relay (which powers the coils w/12 volts w/key to on at the B/Y wire) and Circuit Opening Relay (powers the fuel pump). Again, w/key to on does the B/Y wire at either coil have 12 volts and if not then check/replace the Engine fuse.

Hesstopher

Thanks satch!

> Engine fuse was blown
> replaced, still only 0.04-0.09v to coils.
>> based off what you said, I went down the chain
> located main relay, can't hold flashlight and check things tonight. I'll have to pick it up tomorrow. I'm following this ( https://www.rx7club.com/2nd-generati...-relay-519024/ ) as a guide to checking it. Thread says its a common issue. I'll update this thread either way.

satch

iTrader: (1)

At the relay there is a 4 wire plug. W/no key the B/G and W/L wires should have constant power (if they don't then check the EGI fuses and or the connections to these fuses). W/key to on the other two wires in this plug should have 12 volts (B/W and B/Y wires). If they don't then check the other plug w/two wires. The B/W wire is powered by the Engine fuse and thus should have 12 volts w/key to on. If it does and the B/W and B/Y wires still do not have voltage w/key to on then check the second wire in the two wire plug that is solid Black as it is a ground. The ground is for the coil in the relay and the B/W wire in the same plug powers the coil. Both sides of the coil need to work for the relay to close and take the constant voltage and pass it onto the B/W and B/Y wires in the 4 wire plug.

Hesstopher

ok... my name says it all "South Texas newb"

> tested relay, clicked like a champ. Power is good.
> retested coils, then realized I was checking voltage on the two + terminals (one for each coil in the pack). >.< So I grounded my - prob and checked again... 12v across the board.

I'm waiting on the pump relay before trying to start again. Not a fan of direct wiring my fuel pump-- all red neckish. I'm hanging my hope on the blown engine fuse not allowing the packs to conduct the voltage to the plugs. When I was at the track there was a buddy who checked them (correctly, unlike me) and didn't get 12v... that and the 15amp fuse WAS blown (actually was a 30amp that was blown, probably why the fuel relay died in addition to the engine fuse... been replaced with a proper 15amp)... and the fuel pump relay IS bad (new one scheduled to arrive tomorrow).

Thanks again for the help satch-- I gotta ask, do you just know this stuff off hand or you got a manual it's all written down in?

satch

iTrader: (1)

All info garnered from reading posts plus looking at the wiring diagrams for specific wiring info.

And a blown Engine fuse renders the pump relay useless so perhaps the relay is actually good.

Hesstopher

I tested the relay before I ordered it via direct wire to the battery, simple click test-- no click.

However, before replying--- I just tried starting it... ka-pow. fired up. idles a but rough now, but given the dry turning it has gone through I assumed that would happen.

One thing I need to do... get my testpipes bolted in. Holy crap that's loud. I've run piston engines open header with a dump on them before-- this is insane though.

Thanks for the help satch. guess I can see if the website has a return policy, or I can sell the relay on ebay.

chain autoparts stores wanted >$100 for it, found it online for ~$50.

satch

iTrader: (1)

The relay is supplied voltage from two wires both located on the top row far left positions. The upper left corner wire powers the relay w/key to start only. The wire next to it, top row center position, powers the relay w/the key to on. The relay would only click w/key to on if the Brown wire in the plug had a ground on it (supplied by AFM 'only' w/the engine running). It works this way because the fuel pump is not to run just w/key to on but key to on and engine running as a safety feature. So, if you powered the top left wire it would click. Power the top row center wire and it would not click.

Hesstopher

thanks for the explanation.