No start when cold- fuel pump?

[yodafrick]

Ok, so I've been battling this gremlin on and off for over a week. The first time it happened, it was a sub freezing night, very low tank, went out to start my 88 mini in the morning and nothin. After adding 2 gallons, I figured it was frozen condensation blocking the fuel somewhere. Got her started on ether, but not under her own power. Had to be at work, so I took the wife's 80 and off I went. Got home, and after a day of 40 degree temps she fired right up. Fueled her up, added some dry gas, and thought I was fine. Yeah right...

Fast forward a week of warm weather and no problems. Next cold night, went to start her in the morning, nothing. After last weeks problems, still figured it was gas/condensation prob. Seeing no visible in line fuel filter the last time I followed the line, I poured hot water on what I figured to be the filter (small metal canister at visible end of fuel line under intake/injectors). Sprayed a little ether, and she fired up and then ran on her own power. Drove to work, no problems. Ok, got to change the "filter".

Next day, same thing. Only difference being this time, after h20 treatment and ample use of a blow dryer, nothing. Now I'm thinkin it's a beat fuel pump. Went on mud, did some searching, found out how to jump the pump (thanks Ken!), put the jumper in, nothing. Ok, it's the fuel pump. After about 2 minutes, I hear the fuel pump buzz. Huh, ok. Turn the key and she fires right up. Ok, bad wire to the fuel pump. Check wires, all's good. After work, she fires right up, no issues.

That was Thursday. This morning, I go to start her up, mind you she sat for a day or two and it's been cold, nothing. Pop in the handy paper clip jumper, nothing. Here we go again. Call boss and tell him I won't be in, gotta change my fuel pump. After about 20 mins, turn the key to on position again, and hear the fuel pump buzzin. WTF? No temp change, nothin. Check wires again, alls good. Hop on mud, do some more readin, pop out EFI 15 amp fuse, clean terminals (male and female), same procedure with EFI main relay, both are silghty to fairly corroded. Truck starts no prob on and off for the next hour.

Wait about 6 hours, go out to start her again, nothin. Pop in jumper, nothin. Wait 5 mins, nothin.

So is it time to drop the dough and buy a new fuel pump, or am I missin something? I do realize that fuel pumps do go intermittantly like this, but I'm figuring it's directly related to temps. Is this just because everything is just more strained when it's cold? Should I get a meter and meter the power to the fuel pump at the plug coming off the wiring harness near the tank with the jumper in and the key in the on position? If I have power there, but no buzzing the fuel pumps shot correct? Or could it be my COR? Any help would be appreciated. And I know, I should have just changed the pump today, but my wallets empty and I'd rather rule out the cheaper stuff first. Plus, if it's not the fuel pump, I'm out that dough too. Thanks

 

[Wildman]

First I would do the easy stuff, clean those contacts on the relays! (or swap them out if you think they got damp inside) Throw a bottle of dry gas at it. You are correct, if you dont hear the pump,in the ON position. its not working.

Heres something to try next time it dies. Have a rubber mallet with you (and a buddy) Have the buddy crank it over while you beat on the tank. That will jar the pump into working and then you know %99.99 that the pump is on its way out. FYI: this will get you a couple starts.

There may also be a loose wire on the top of the tank thats being shaken around, but youll be able to figure that out when you drop the tank. The pumps arent cheep, I would check and make sure your almost positive that its accualy a pump.

 

[crusier72]

How rusty is you're truck? I'm assuming that since it's 20 years old it's kinda krusty double check you're lines to make sure there aren't any leaks anywhere. I've seen rusty lines cause problems before. If you don't have one get a test light that way you can double check that the power is getting to where it's supposed to.

 

[yodafrick]

Wildman- thanks for the input. I did clean the relays, terminals, etc yesterday. I also checked all the wiring about six times over now. I'll try the mallet thing next time it won't start. It's wierd though, even with that jumper in, it doesn't buzz for a few minutes. I think I'm gonna try to find some slightly used but good relays to swap with. They (Toyota) want 110 for the COR!

Cruiser 72- yeah, it's rusty, and actually the fuel line looks like it has been replaced by the PO. I'm guessing that's why there is no filter? It was replaced with ~ 1/2 in. fuel line that says on it EFI fuel line. The large zip ties replacing the fasteners scream PO job. Other than that, the lines are ok. Grabbed my test light today from my garage today (renting sucks) and am going to check constant power with and without the jumper.

Thanks for the suggestions!

 

[Wildman]

I'm guessing that's why there is no filter?

I dont get it, didnt you say you did the filter under the intake? And is the WHOLE fuel system rubber now? there is a chance that its breaking down and clogging things up.

 

[yodafrick]

Having no FSM for this truck, I'm not positive what I described as the possible "filter" is. There is definately no inline filter. The fuel hose is rubber, giong from the tank, along the frame rails, into the engine compartment, and under the manifold to a metal canister the size of a small soup can. I'm not exactly sure what this is. I assume it's a filter, but not sure why it would be so unaccessable if it was. I'm guessing by what Mark is saying that the original fuel line was metal, but since this is my first mini in about ten years, I don't recall.


Fuel line doesn't seem to be the problem though. I'm pretty sure it's a bad fuel pump by now. I understand that once the jumper is in the diagnostic port there is constant power going to the fuel pump. I'm just still confused why there is no power for about two minutes after I put in the jumper and then the fuel pump kicks in and buzzes. This time period is consistent every time. That's why I keep thinking it's a relay. After I hear it buzz, it starts fine every time. I just don't want to replace the pump and have the same intermittant problem, that's all. Just wondering if I'm missing something. I appreciate the help and am not argueing, just trying to accurately describe what's happening.

So now for the last two mornings (still cold), she's been starting fine. I also read somewhere that the fuel pumps have an internal relay of some sort. Maybe that's the problem. I've also been told that the fuel pump bracket will have to be replaced so I'm sourcing that too.

 

[2ndGenToyotaFan]

Yes, the soup can under the intake is the filter.... we all loath it... Sounds like you're on the right track...