91-94yota

Hello folks, new problem not sure that the previous posts are an issue any longer. When I jump the E1 and Te1 terminals my check engine light just blinks steady without any code reference pauses or anything. It almost seems like I'm not getting any fuel, is there a pump fuse or anything I can check? I'm having a heck of a time finding fuse references for my 91 base model 2wd 22re pickup.

Co_94_PU

iTrader: (-1)

Are, or are not! There is no seems like...

Locate the fuel return line (large hose) off the pressure regulator. Disconnect it from the return hard-line and place it into an empty clear bottle, now jumper the fuel pump.

What you are looking for is called "junction block #1". A quick Google pops up..


(Ignore the added notation)

If you don't already have a multi meter you need one. A good inexpensive source is your loca harbor freight, no need for an expensive calibrated professional one just need in the ball park numbers and functionality.. They are like USD/5, and some times free with coupons, no excuse not to have one.

Check for ground continuity on the FP line in the diagnostics box. Check for battery voltage on B+ on the diagnostics box. Connect these two diagnostics ports and you should be able to measure flow into the bottle. This verifies the fuel pump circuit is intact from the front of the vehicle to the tank..

Now try it without the FP jumper while the key is held into the start position you should have flow into the catch bottle. Next test the VAFM signal by pushing the flapper (vane) open with no jumper and the catch bottle in place, this verifies the vafm signal reaches the COR (circuit opening relay, aka fuel pump relay)..


You really need to get the FSM (factory service manual) or at the least a Chilton's or Haynes manual from the local bigbox store..

PDF versions of the FSM are in the sticky threads and available from the internet archive (way back machine) and in larger cities the library has print copies of lots of these automotive manuals.

scope103

Uh, what's in Junction Block 1? http://web.archive.org/web/200902190.../2powersou.pdf
While 91-94yota's problem is less likely to be a fuse, the fuse that covers the fuel pump is the MFI[EFI] fuse in Relay Block 2. It is almost certainly not the fuse, because he is getting the CEL.

The rest of the procedure is spot on. (Though, I would first jumper FP to B+ and just try to start it. If it starts then, the rest of the procedure locates the actual problem.)

91-94yota

Gents,

I checked all fuses, contacts, and relays to no avail, turns out that the ECU is not sending the correct signal to the fuel pump, so it wouldn't start. Swapped in the ECU from my 94 and she fired immediately, so that tells me what I have to replace, if I am missing something please let me know. My apologies for all the issues of my last couple posts, I am grasping at straws until I can learn where everything is and the proper names. Thanks again.

matt z

scope103

The ECU has nothing to do with the fuel pump. Changing the ECU might have done something, and that something might have allowed your vehicle to start. But there is no "signal" from the ECU to the fuel pump.

91-94yota

I was under the impression that the ECU sent power through the EFI relays and allowed power to the pump. Guess I'm back at square one again, thanks for the heads up.
Matt z

scope103

If the ECU "sent power" through the EFI relay (only one), where did the ECU GET that power? (The ECU is powered through the EFI relay, not the other way around.)

If your problem was that the ECU wasn't sending power to the EFI relay, why was your relay closing (you can hear the click)? Why did you have battery voltage at B+ with key-on? (You did check, didn't you?)

You have a (slightly) complex machine, which is well documented (the Toyota EWD - electrical wiring diagram). When any machine stops working, you have to use your head (and a multimeter) to figure out what is wrong with it, in order to fix it. Too many people pass through this forum with a fear of reading, so when their truck stops working, they just start swapping parts blindly like it was a giant Lego. Don't be like that. Try to get an EWD (even the Haynes manual will give you a leg-up). Figure out what you think is wrong BEFORE you start replacing parts.

Good luck!