NewXJaddict

Update: I now can get power to the pump but only by bridging the 30 and 86 slots on the relay socket. However even with the pump buzzing I still get no fuel to the rail.






OK. Getting really tired of this fuel pump issue.

I took the one I thought was bad back to NAPA and they tested the pump and it works fine. I got a test light from them and checked to see if there was any power going to the fuel pump. (I know, this is the reverse order I should do thing in, just how it worked out)

So there is no power going to the fuel pump. I can only see about 4 inches or so of the wires to the fuel pump then it dives into the body somewhere.

Where do these wires go and where else can I find another point to test for power?

I have already swapped out the fuel pump relay with a known working one so as far as I can tell it's not a relay issue.

Any ideas or help is much appreciated.

ol"blue

Don't have a clue about the Renix system, sorry. Don't have an '87 wiring diagram either. Batting 0 for 2 here Chad.

89Laredo

check for power at the relay socket (30 to ground, then 86 to ground)


Remember that the FP relay is only activated for 2 seconds when you turn the key on. Best bet is to watch the meter (or test light in your scenario) and have someone turn the key for you.

If you have power at the relay, check your ballast resistor. Best way is to jump the contacts with a piece of wire and never look back.


Do you have a FSM? if not, PM me.

NewXJaddict

I have the Haynes manual. It has the wiring diagram but in no relation to the vehicle. I do have a downloaded copy of the FSM for 88 (should be about the same I would guess.

I tried testing the ballast resistor the other day.

I just need a freaking extra set of hands/eyes

It's driving me crazy.

NewXJaddict

Ok it seems that in the socket 30 to ground works. (ran test light from 30 to a regular ground wire that I saw screwed into the metal)

30 works every time all the time. The other one (86) is the one that only comes on for a couple seconds when the key is turned right?

Would hooking the test light to 86 and to a ground then pulling the neg bat cable then re attaching it while the key is on work too? I just don't have anyone to turn the key while I watch lol.

89Laredo

I think that would work (reconnecting batt. neg).
Actually, now that I think of it:
If you can hear the FP run outside the vehicle (I know I can hear mine from in front of it, or 5 ft away) just jump 30 to 87 with a piece of wire and see if the pump runs.

NewXJaddict

Yeah. Before I broke down I could hear it kick on clear as day. Since then I have not heard it come on at all.

Not with the pump that was in there when I broke down or the new one. I just got everything hooked back up for the 3rd time or so (hoses and wires all connected together)

Came inside for a sec to check up on this and get a drink.

I hate electrical problems.

NewXJaddict

ok...bridging 86 to 30 on the terminal lit the test light .... fuel pump did not kick on and no fuel to the rail.

Throttle Jockey

make sure you have a good ground. from battery to body and engine to body. mine is a 90 and the pump will not run without the body to engine ground strap.

NewXJaddict

I was reading through the FSM thing I had downloaded too. It says something about the starter motor relay...It has an arrow pointing to nothing...or pointing to something that I can't tell where it is actually pointing.

Starter Motor Relay
Although no switch or sensor is used, the ECU requires this
information for fuel enrichment during starting. This information is
passed on the the ECU through the starter motor relay.

so does this mean that if the starter motor relay is bad then it is also a possible reason I wouldn't get fuel?

I also have no idea where else the wires for the fuel pump go after they enter the bottom of the floor.

89Laredo

30 to 87, not 86

NewXJaddict

yeah 87, that's what I intended to say. But yeah, 30 to 87 lights the bulb but still does not get the fuel pump to come on.


As for the grounds..I found the one that goes from the battery to the motor but I can't seem to find the one that goes from motor to body.

89Laredo

its in the back of the head, ground strap goes to the firewall.
Try it with a piece of wire, instead of your test light (though It should still run with the test light, its worth a try).
When I get a chance Ill look over my FSM and Renix manual, but that might not be till tonight.

NewXJaddict

ohh.. ok ...looks like plain silver braided wire?

89Laredo

yup