No power to fuel pump. Car cranks but won't start!

MissySoarer

New Member
HI! I have a Japanese Toyota Soarer UZZ31 V8.

I'm thinking a relay or fuse is out but have no idea where to start. If someone can provide a pic of the fuses/relays I should be concerned with I'd appreciate it.


My car will not start. It turns over, and won't start. No power to fuel pump. It starts when I attach a wire from the battery to the fuel pump behind the back seats and apply throttle. I have wired an on/off switch from battery to the fuel pump for now.

FP and B+ doesn't seem to do anything either (fuel ECU bypass). I cannot seem to check diagnostics with the paper clip/wires, and there doesn't seem to be anything coming out of B+ in the diagnostics port of the engine bay.
Since the fuel pump/no start thing began, if I try flooring the accelerator the car doesn't want to go properly. Seems to struggle and then pick up then struggle then pickup. (Didn't do this before the fuel pump problem started).
Car also has developed a battery drain I think. Maybe related to fuel pump problem. Battery is at 12.5v after a 20 minute drive, and letting it sit for 6-12 hours after fully charged on the battery charger brings it down to 12.1v... Pulling negative cable off the thing stops the drain. (Switch under dash for remote key is turned off).


I've replaced main engine ECU with 3 known working reconditioned units, same symptoms. (Huge waste of cash also...).
I've bought a new battery, 610cca. Previous battery was 680cca (had a dead cell. 10.4v maxed out).
I've checked all fuses (under hood) but have no idea how to check relays or which relay for that matter is the one in question. I have a multimeter though!

Any advice would be very helpful and appreciated sooOOOooo much lol!

P.S. Car won't idle either. Sometimes stalls as the idle is under 300rpm's. Must keep foot on accelerator slightly (This problem was happening before the fuel pump/no start condition - don't think it's related).
 

gloverman

Well-Known Member
I would maybe start with checking alternator output. I see lots fail due to powersteer fluid injestion. If its not performing correctly i would also be checking the small control wiring as well before removing. I think you can access these wires on the RH front behind or below the AFM. Theres a joiner for the main output wire with a plastic cover under there. Do you know how to check the supply wiring?

The no power to +b is interesting too. I would be using my test light to trace this. Im sure there is a second EFI2 fuse which supplies voltage to +b in diagnostic, IAC and maybe the fuel pump circuit as well. The is a connector on the LH side of engine bay near ignitors with this wire in it. Large red black from memory. I comes from main efi relay which also supplies voltage to ecu so i suspect the relay is ok.
 

MissySoarer

New Member
Hello :)

Alternator is 14V when over 1000rpm with the multimeter over the battery terminals. I'm not sure what you mean by 'small control wiring'?
I have a power steering leak from the reservoir apparently. Must top up every month or two. No damage to alternator yet it looks like.
I've heard if the power steering vacuum lines are corroded that it causes vacuum leaks and idle problems... I'll have to look into it.

Could you please show a pic of the 'igniters'. I'm confused with terminology.
Igniters to some people mean the ignition coils, to other people it's the relay things, and so on.
Also if you can find a pic of the wire in question, that'd be swell too!

Thanks for the info Gloverman.
 

MissySoarer

New Member
Ok lets try this if anyone can help. I may have typed a bit much.


Starting over.
Car cranks but won't fire. Fuel pump has no power.

1. Bridging FP to B+ does nothing. Car won't fire. Just cranks.
2. Attaching a physical wire from battery to fuel pump lets the car fire and stay running.
3. Battery is 12.6v.


What does this suggest? A relay is out? Which one?
 

gloverman

Well-Known Member
As stated the ignitiors are on the LH side of the engine bay. The connector which the 12 volt supply which runs through the loom for the fuel pump control ecu is in there. I would be confirming if that wire has 12 volts or not. If it does then issue is further back in the car. If it doesn't then issue is likely in front fuse box.
 

MissySoarer

New Member
So... I found the 'igniters' on the right hand side of the engine bay, not left hand.
Moved house and lost the multimeter so waiting on a new one from Ebay to arrive, then will be able to check properly.
What's the best process to check the igniters with a standard multimeter?
Car on or off? Cranking or not?
NOt quite sure how the ignition system works on these cars as you can probably tell.

Thanks again!
 

numbchux

Member
If it'll run with a hardwired fuel pump, than your igniters are fine.

I don't have the diagrams in front of me, but off the top of my head, I think that B+ is through a separate EFI fuse/relay, and provides power to the IAC, and Fuel pump controller at the very least. So yea, I'd be finding that (on my '94 SC400 donor, it was in the fuse/relay box right next to the battery) and testing from there.
 

gloverman

Well-Known Member
Not to be rude but Japanese soarer definately have the ignitors on the LH side of the engine bay. They are a RH drive vehicle and everything is done relative to that so passenger side is LH where ignitors are found, behind fuse box. I
 

gloverman

Well-Known Member
The power wire which supplies the fuel pump controller run through the connectors which are in the same loom as the ignitors. Located in front of the fuse box.
 

dailey

Member
Try turning the car on then taping the EFI relay.
I've had this issue with my car. Efi relay not closing or getting stuck on.
 

dailey

Member
Im having this problem again.
Just finished tidying up the wiring.
Im only getting 4.5 - 5V across the main relay coil. (10.5 V with the relay unplugged), not enough to close the contacts.
Relay earth is fine.
Batt voltage is a little low, 11.8V. Its on charge now.
Wondering if its an ECU earth issue, or the 27 year old relay.
 
Top