Way to test Fuel Pump Relay?

[thomp1983]

Whilst the relay itself may physically work it may not be getting the switch signal to activate it. You could pop the relay lid off and switch it manually and see if it starts

[IMR2T]

Hmm, not that clued up about electrics but that's a great idea! Cheers mate!

[thomp1983]

Don't switch the relay by hand use something insulated i do it with a cocktail stick.

First check there's 12v and an earth to the wiring connector for the co relay

[IMR2T]

Ha, ok, got mixing sticks for my paint 👍

So I'll pop ignition on and use the circuit tester on the connections on lead side yeah?

[MartinF]

Ok, will get a look under the fuse box, is there potential of burnt out wires?!

Yeah mate, normal lights all come on.

Yeah belts done along with AC and Altenator belt. When cranking it turns over normally and sounds normal.

-All my plugs are sparking.
-I have fuel in the tank.
-I've tried the diagnostic port fuel pump bridge and it comes on straight away.

Either jacking the drivers side of the engine up and down has loosened something or my Clifford's being a d*ck!

I think you're getting in a bit too deep checking relays etc. before checking basics. If you take your plugs out after trying to start the car are they wet with fuel ?

BTW....if cam timing is well out car may not start.

[thomp1983]

Put up a picture of your meter, you want it on volts dc, the black probe in the earth pin (white/black) and the red in the switched live (yellow/black) and you should have 12v with the ignition on.

When you try to start the car you should have 12v showing on the red wire and blue/black wire.

Martin he said the car starts and runs with the fuel pump bridged so it looks electrical

[Peter Gidden]

Checking CO relay is a two minute job.

Tools required - multimeter and wiring diagram.

Simply check for 12+VE and earth at CO relay socket terminals when cranking.

[IMR2T]

Ok, will get a look under the fuse box, is there potential of burnt out wires?!

Yeah mate, normal lights all come on.

Yeah belts done along with AC and Altenator belt. When cranking it turns over normally and sounds normal.

-All my plugs are sparking.
-I have fuel in the tank.
-I've tried the diagnostic port fuel pump bridge and it comes on straight away.

Either jacking the drivers side of the engine up and down has loosened something or my Clifford's being a d*ck!

I think you're getting in a bit too deep checking relays etc. before checking basics. If you take your plugs out after trying to start the car are they wet with fuel ?

BTW....if cam timing is well out car may not start.

Plugs are dry, first realised there was no fuel as I pulled the fuel line off my FPR and there was no fuel getting through.

[IMR2T]

Put up a picture of your meter, you want it on volts dc, the black probe in the earth pin (white/black) and the red in the switched live (yellow/black) and you should have 12v with the ignition on.

When you try to start the car you should have 12v showing on the red wire and blue/black wire.

Martin he said the car starts and runs with the fuel pump bridged so it looks electrical

Mate I've got a hundred odd pics to start a rebuild thread and my photobucket app is frozen and not uploading my recent pics...gutted as I've done a fair bit to the car since I trailered it home.

Will try that with the multimeter

Hmm, if it starts with the diagnostic ports bridged then I'm starting to think its my Clifford alarm...

[IMR2T]

Checking CO relay is a two minute job.

Tools required - multimeter and wiring diagram.

Simply check for 12+VE and earth at CO relay socket terminals when cranking.

Sorted, will do mate

[IMR2T]

Update

CO relay has continuity(still to take cover off and manually switch it).
CO terminals read 12v when ignitions on and 10.33volts when cranking.

Power probe shows no grounds only positives in both CO and Pump spade terminals - that normal?

[Peter Gidden]

Power probe shows no grounds only positives in both CO and Pump spade terminals - that normal?

If you check your wiring diagram you'll see CO relay and EFI relay are both supplied earth by the same wire.

[IMR2T]

Yeah, the probe didn't illuminate green though, positives all lit up though.

I'm looking at my alarm more and more now...

[thomp1983]

i wouldn't think your alarm would immobilise the earth part of the circuit, did you check the wiring under the fuse box as you thought you could hear shorting.

id be employing the mk1 eyeball before doing any more tests and look for any damage to the wiring

[Peter Gidden]

Yeah, the probe didn't illuminate green though, positives all lit up though.

I'm looking at my alarm more and more now...

Your alarm? Why?

Use the diagram to trace the earth to it's origin.

[IMR2T]

When I first got the car it wouldnt start(it turned out to be the indium plugs the car came with weren't producing a gd enough spark. Copper NGK 5's fixed that). Before I figured out the plugs needed changed a Toyota master tech said the main reason most MR2's didn't start with him was the wiring of aftermarket alarms causing issues at the ignition barrel.

Mate tracing origins of wires from diagrams is outside my capabilities. I'm more of a Clarkson 'Get the hammer on it' type of guy.

My mate wants me to power probe the pump under the gearstick to power up the pump and try start it but I don't see the difference between brigding the diagnostic port and probing the actual pump terminals.

In all honesty this cars been kicking my ass for a few wks and although Ive sorted most of it myself, I'm going to call an auto-electrician to come out to fix it. I'm stumped.