No power to fuel pump.

[S.A. supra]

I can't get the fuel pump to kick on. I tried to jump the fp to b+ to get it to kick on but no luck. B+ seems to be my problem. I get 12v to my inj coils and ign. Also I was checking to see if my isvc had power and found that both black and red wires were clipped. Would this keep the engine from starting?

 

[Satan]

Check your main power signals/circuits (main relay, several power/ground wires at the ECU, etc).

 

[IndigoMKII]

So you have no power to the b+ terminal, you could always take a jumper and go from the positive on the battery to FP.

Yes, the ISCV can keep the car from running. Consider what ISCV means, idle speed control valve, with the TB completely shut there's no air to the engine thus the ISCV lets air into the intake at a controlled rate due to the stepper motor.

You could try checking the EFI fuses and relays along with the fuses at the kick panel in the car. When you turn the key switch on do you see the CEL come on?

 

[S.A. supra]

I guess I should of mentioned that this is a 2jzgte swap into a 87. I haven't got it to run yet. I went back and looked at the wiring write up that dingle posted on page 5 of the 2jzgte wiring stickies. I think I may have found the problem. I just need to verify that the c1 pin 4 runs to three different pins. That being e10 pins 31and32 also the b1 pin 9.

 

[S.A. supra]

Well the fuel pump comes on sometimes and sometimes not. I have no clue why , I swap relays and still no go. If I jump the fp to the battery, and it fires up.

 

[Satan]

We are having a similar issue with a 1J into a pre-89. Did the 12v mod and the pump runs when B+ and Fp jumpered in diag box (check connector) with the Ign Switch, but not when those signals are jumpered at the FP relay instead (like the 12v mod calls for).

Am looking at page FI-70 in the TRSM and it looks like the Circuit Open Relay is the culprit, but means that the Fp signal/circuit is not making it thru the COR to the Fuel Pump Relay. So, we are looking to bypass the other relays anyways and just jumper the B+ and Fp somewhere other than at the FP relay.

Will be troubleshooting the circuit open relay today, to see if we can find the real issue, but we at least have the alternative above.

 

[S.A. supra]

Let me know what you find.... I can't figure out why it works onlysometimes. I tried another cor and it does the same thing. Please keep me updated on your findings. I'll be working on her all day tomorrow. If nothing else am gonna b+ it.

 

[Satan]

As I see it, jumpering at the Diag box is the same as jumpering at the Fuel Pump Relay. In either case, the other relays/signals (large red outline in lower left of pic) are eliminated or cut-off by closing that circuit. This is what we'll probably do tonight...

Do you also have the 12v mod?

 

[S.A. supra]

No, no 12v mod right now. Gonna jump it for now just to get it running. Then do the v12 mod later, because I am running a 255.

 

[S.A. supra]

I don't know what exactly is going on., but I found the problem. It was the main relay in the fuse box. I tapped it with my finger and my fuel pump kicks on. But if I disconnect my battery it stops working when I reconnect it. It did this time and time again and every time I thump it , the fuel pump kicks on. I even tried five different relays, swapped out the whole fuse box, and squeezed all the connections on the fuse box tight. To make sure they were making a good connection. Still nothing worked ....same results. So I whacked the relay with a screwdriver and it works every time. It took three hrs to get to that solution.

 

[S.A. supra]

Still having this problem! It's been in sitting for a while now. I have been getting it ready for the road, and would like to solve this problem. It will work if i tap the main relay, but when i turn it off I have to tap it again to get it started. any help would be appeciated.

 

[Satan]

Have you replaced that relay? Could be that it was sticking/faulty. We permanently jumpered the B+ and FP at the diag box and went with the 12-volt mod. Everything else, wiring-wise, is fine (or as it should be).

 

[S.A. supra]

I'm gonna try that tomorrow. My battery died, but ill let you know. Thanks for your response.

 

[S.A. supra]

Ok, I noticed the other day when my battery was dying I had to tap the relay harder and progressively harder till it wouldn't kick on the pump any more. Also when I went to turn over the engine the starter wouldn't kick it over. So I fully charged the battery and now it works every time. I noticed my battery light is on, so I'm thinking its time to have the alternator checked out. If it checks out good then I'll have to check the wiring. I hope this all pans out.

 

[S.A. supra]

OK, I think i can call this one solved. I checked the alternator wirirng and it all checked out. then i noticed that the battery feed wire was not tighten. So i tightened it and now no more battery light, and it startes every time. satan thanks for the help. Now on to the next problem.