Energizing Fuel Pump

I have a '98 Tacoma with the 3.4L V6. Started getting a miss. Got a 305 code indicating a misfire on #5, and traced that issue to a non-firing injector. (It was getting pulse, but not firing.)

I'm not one of those guys who changes just one plug or one injector. Especially with 280K miles on the clock. So I bought a set of supposedly OEM reconditioned "matched" injectors off eBay ($100 with shipping for all six), and installed them. Started the truck. Ran perfect with no misses, but what was that smell? Turns out I have a leaker somewhere on the driver's side. Since you can't see under the manifold on that side, I don't know which one. (but you could see gas filling up that side so I know it's there.) I have since had this thing back apart twice, double-checking installation and rubber parts. There is nothing wrong - at least that I can see - with the injector seals or O-rings. But I went ahead and replaced them anyway today. But have not put it back togehter just yet.

My question is this: Is there a way to energize the fuel pump on this truck without putting the whole freakin thing back together and hitting the starter? I've been able to do this on other FI cars by various methods, but I've been all over the internet for most of the afternoon and can't find how to do that for this specific truck and engine. I did find a great trick for jumping two pins of the Data Link Connector, and ran excitedly outside only to find my truck does not seem to have one of these, at least attached to the underhood fuse box where the picture shows it.

I just want some way to get the fuel pump to turn on and get pressure to the fuel rails so I can easily see where and what is leaking before I button everything back up.

I have read that some eBay injectors leak from the body of the injector. I hope that is not the problem, but if it is, I guess I will learn my lesson about cheap injectors. Hoping that is not the case tho.

 

FP to BP+in the junction box with a paperclip

 

Ok, thanks. I understand the paper clip part (LOL), but not exactly what or where the junction box is, much less which plugs are BP and FP. Is the junction box the fuse box under the hood? If so, I still don't understand where to jump from and to - they're all fuses or relays and none is marked BP or FP. Sorry to be so dense.

 

Flip open the cap on that and look inside it, it will tell you which is which

 

Yeah its that lil diagnostic port in the engine bay(posted above).Not either of the two fuse boxes in the truck!

 

Ok. Great! Thanks much. Ill try it first thing in the morning!

 

Perhaps Toyota changed how it's labeled, but I've seen Fp and +B for "Fuel pump" and "positive Battery" on other Toyotas.

After jumping with a paper clip you have to turn the key to the ON position.

 

You of course are correct, it was a typo, sorry

 

Wow, some good tech here. So rare on TW these days. Thanx guys.

IMHO, about 90% of the posts and threads on TW are mindless BS. So annoying.

 

Update: Okay, so I found the junction box (dangling to the side since the manifolds are off). And I found +B and Fp. And I bridged them with a paper clip, ignition on. And I got . . . nothing. That is to say, I did not hear anything (like the pump coming on) and I did not see any leaks at my injectors. Now of course this could mean that there ARE no longer any leaky injectors, which would mean I solved the problem. However, I am used to hearing the fuel pump on other cars. Are Toyota pumps (in-tank, right?) that quiet?
Also, when peering into the junction box, I see a nice female clip in the +B slot, but - at first glance - nothing in the Fp slot. A flashlight shows that there is a small metallic tab waaay down in there. I did attempt to contact that when bridging with the paper clip. (And yes, the ground wire normally bolted to the manifold was grounded.)
For one more try, since the battery is right there, I went directly from the positive terminal to the Fp slot. Still no sound and no leaks.
I guess at this point I'll put it all back together (again) and hope the fat lady sings. Will let you all know how it goes.

 

Since that didnt work for you and you still have it apart can you swap injectors from one side to the other? I would allso clean out where the injectors go in and apply a little lube to the o rings before re installing them.

 

I have cleaned out both ends where the injectors go a couple times - both in the fuel rail and the manifold end. Spritzed a little carb cleaner in there, swabbed with clean paper towels and blew out with compressed air. I did not see any scratches or flaws or anything like that that could cause a leak (and no real reason to expect any, since the old injectors sealed fine and didn't leak). Also as mentioned, no flaws that I could see on the O-rings or seals that the refurbed injectors came with. I even tried to measure the O-rings with a micrometer (like measuring jello, incidentally) and they all seemed to be the same as the new ones I put on.
I also squished the rubber stuff (that came with the injectors) around between my fingers under a strong light before putting the new kits on, and could find no flaws or cuts or deformities in any of it.
I do lube any rubber parts before install with a light coating of silicon grease. After the first leak session, I took it everything apart and lubed the O-rings with gasoline as suggested on several posts detailing this procedure. Still leaked.
I have lightly lubed the new rubber with silicone grease again - a procedure that an old mechanic told me about and which has always served me well, since it helps preserve and freshen the rubber (or so he said).
As for the swapping idea, I had not thought of that before, but it is a great idea. Since I don't have any leaks on the passenger side - where I can see everything - I will swap the three on starboard with the three on port. And if I do have one leaking out of the body itself, I will be able to see it. Thanks HairyTaco!
Stand by. Film at 11...

 

Toyota might have removed the Fp functionality. That "check connector" had more diagnostic functions before moving to OBD-II.

Can you fit an inspection mirror under the manifold to find the leak?

And you have the rubber grommet, o-ring and insulator on each injector?

 

Success! I don't know if it was bad seals, faulty O-rings, correcting 'operator error' or just plain luck, but the third time was a charm - no leaks, truck runs smooth with no faults or 'check engine' light, and I'm a happy camper. Seems to even run a bit smoother and peppier with the new injectors - but I think that every time I do anything do it. LOL.

For reference, the truck has 291,000 miles and this is the first "major" replacement I've ever done to it except for the timing belt. (Got it with about 190K, so we've put about 100K on it ourselves.) It has had more or less regular maintenance and fluid changes (syn oil only) since we've had it. I wish it got a bit better mileage (18-19 at best), but ya gotta love the power when you need it. Auto tranny is also still nice and tight and shifts very well.

In case anyone wants to know, the eBay injectors were billed as "OEM Flow Matched" and the seller was dimarmotorsportsllc. They cost $67, arrived within two days of BIN and shipping was free. New rubber for each injector (2 O-rings, 2 seals) was from Napa and cost $18 for all six. So not counting my time (or you guys' time LOL), the repair cost me less than

 

Oops, what happened?
Anyway, the repair cost less than $100 and I learned something. I'm also now really good at taking apart the manifolds.
Thanks much for your help!

Oh, and I think DrZ is right about Toyota eliminating the Fp clip in the junction box.

 

Important INFO

 

Another trick is to remove the starter relay, then turn the key to START. This will energize the fuel pump without cranking the engine. Without an assistant this limits you to just hearing the pump running and afterward checking for leaks.