Printable Version of Topic

Posted by: Jon H. Sep 9 2013, 07:52 PM

As the title states what do these two things have in common that would cause them both to stop functioning at the same time? No clicks from TPS and no 1.5 sec running of fuel pump. I have checked the engine wiring harness for continuity and all is good, the ECU is getting power, the pump will run if jumped, I get injector pulse while cranking, power at coil, swapped relay board with another, power at fuse #8, checked grounds at engine and at ECU plug.

I have read that a failing TPS will cause an engine to buck as the TPS cuts fuel off to the injectors but could the TPS actually cause the fuel pump not to cycle in key on position? If the engine will run with out the TPS plugged in then I assume that it shouldn't cause the fuel pump to not cycle? I have had this running for about a week now and it would fire right up and I went out tonight and now it won't start.

Any ideas?

Jon

Posted by: 914Sixer Sep 9 2013, 09:22 PM

Check the wire at the bottom of the heater lever. Fuel pump relay also runs power to blower motor. If you have a problem with the wire to the blower, the fuel pump will not run. This might be a possibility.

Posted by: luskesq Sep 9 2013, 09:41 PM

In addition check your relay on the board in the engine bay. Don't believe there is any correlation between a bad TPS and the fuel pump not working. You can swap in one of the other relays on the board (make sure it works) to see if you have a bad relay. There is a way to jumper the relay socket for the fuel pump to see if the pump works but I don't recall the two pins to jump. Perhaps someone else will chime in on that.

Good luck,

Keith

Posted by: Cap'n Krusty Sep 9 2013, 09:47 PM

That is simply NOT TRUE. The FI power relay supplies power to the pump relay, which powers up the pump. The heater blower relay supplies power to the heater blower. The 3 relays may be swapped around as they're identical in bunction (as are the headlight motor relays).

The Cap'n

Posted by: Jon H. Sep 10 2013, 04:57 AM

I have swapped around the relays and put a jumper to the pin that activates the fuel pump (to test the pump and check the wiring from the fuel pump to the board). The Brad Anders flow charts don't work on my Mac so I'll have to print them off today at work and try to follow them later this week. I did have this problem before while I was trying to get my car up and running but I thought I fixed it after cleaning the ECU main molex connector. I wasn't getting TPS clicking when the shop was cold, well its been warm all summer and the temp has now been dropping off so I think I solved nothing, sigh! It was cool yesterday. If this is the same issue I'm thinking ECU trace problem.

As for heater blower motor, I have none. It was all remove by the PO. This car was used for Ax.

I will jumper the fuel pump so it will run when key on and see if the car runs.



Jon

Posted by: toadman Sep 10 2013, 06:18 AM

Try a known, good ECU that is correct for your car.

Posted by: Jon H. Sep 10 2013, 08:16 AM

I think I will try and source another ECU, I did jump the fuel pump and took in for a safety this morning and had my first ride on the highway now I can sort out the rest of the car over the winter.

Thanks for the replies!

Jon