99 pass port fuel pump problem

I replaced just my fuel sender, which fixed my gas gauge problem.
Now, the fuel pump does not make the 3 second wirr sound to prime the system when the engines hot.

When the engines cools, no problem. It starts right up and you could drinve to Alaska, just don't shut off the engine!

what the heak is wrong?

loose connection

I firmly believe that Amigo is right...

My Rodeo had this exact problem (with others too). For a couple days, I ran the fuel pump direct to battery (switched) and the problem did not reappear.

I then ran a new wire (with an inline fuse) directly from the relay to the fuel pump. Ran a new ground directly to the frame and I haven't had any starting issues since. That was about a month ago.

We have had -35c weather the past week, and still, starts and runs great.

I'd start by running the pump direct to the battery and I'll bet your problems will dissapear. (Make sure you fuse the wire though, I *think* it's 10A).

Steve

Thats what I want to do, check for power and then run a new fused wire to it. I'll check it out over the weekend. And I have to say the response was very quick, this is amazing.

One question though, when you ran that new wire from the relay, do you still get the 3-5 second fuel pump prime sound or is it constantly on?

Does that make a difference? Why does it have to prime it up and then stop? Is that for safty reasons?

Thats what I want to do, check for power and then run a new fused wire to it. I'll check it out over the weekend. And I have to say the response was very quick, this is amazing.

One question though, when you ran that new wire from the relay, do you still get the 3-5 second fuel pump prime sound or is it constantly on?

Does that make a difference? Why does it have to prime it up and then stop? Is that for safty reasons?

I honestly didn't check. It just works. I know for fact though, that when it was from the battery, it was on full time.

I'm not to worried whether it shuts itself off after 3-5 seconds anyway...my 'zu is running by then ;o)

Seriously though, as far as I know, the pump is not variable, so no matter what state the engine is (high RPM, load, no load etc), the pump operates at the same speed anyway, so I figure no damage can happen.

The only reason I ran it off the original relay was so it would at least half-ways be the way it was, and I'd safely be able to use the ignition trigger to fire the pump properly.

It works, so it stays. I do stress again though, to use a good wire and a fuse.

I actually ripped off the back of the under-hood fuse box and brought the wire out of there. The fuse is outside the box, in a proper sealed fuse container so I can get at it easily.

Since I didn't know the exact path the original wire took, I though this was the easiest solution.

Best of luck, I was near ready to drop the tank and pull the pump.

Steve

How long has it been runnig like that?

How long has it been runnig like that?

Just shy of a month now. Absolutely no problems whatsoever since.

I was so happy, I looked at everything before that, because everytime I put the fuel pressure tester to it, it worked. I didn't consider a loose connection at that point.

It was so frustrating, but things are much better now!

Steve

I'll let you know. Thanks

Pump still quits

Pump still quits

Time to drop the tank. It's either wiring inside the tank, or the pump itself has gone bad.

Steve

yes when I directly ran a 12 volt line to it, it ran for a while then stops. After a while, it will run again, intermitently

yes when I directly ran a 12 volt line to it, it ran for a while then stops. After a while, it will run again, intermitently

I'm sorry to hear that. I was hoping it would be an easy/quick fix like mine (mind you it took me quite a while to find it out).

Good luck...let me know when you find out exactly what the problem is.

Steve

St charles said maybe I have to have the ecu reset whenever replacing the fuel sender (which I replace) It worked for a while, then the fuel pump started acting up. I don't think resetting the ecu won't do anything since I ran a hot wire directly to it and got the said problems.

St charles said maybe I have to have the ecu reset whenever replacing the fuel sender (which I replace) It worked for a while, then the fuel pump started acting up. I don't think resetting the ecu won't do anything since I ran a hot wire directly to it and got the said problems.

I have read on many forums that some vehicles need the reset after a sending unit replacement.

Now, that said, the pump should run all the time if wired direct, however, the injectors are controlled by the computer. Are you certain it's the pump cutting out and not the injectors? Have you tried putting a pressure guage on the fuel line?

But a hotwire to the fuel pump will energize it right?

In regards to fuel pressure, I don't have a fuil pressure gauge, but whenerver I press the fitting on the fuil rail, the gas squirts with very high pressure, so there is definite gas at the injectors.

But a hotwire to the fuel pump will energize it right?

In regards to fuel pressure, I don't have a fuil pressure gauge, but whenerver I press the fitting on the fuil rail, the gas squirts with very high pressure, so there is definite gas at the injectors.

Q1: Yes, well...it should because you are running it direct.

Q2: Hmmm. Does the fuel squirt out even in the no-start condition? Can you hear the pump running at all with it hooked up direct, with the vehicle off?

If you can't hear it at all, then the problem is internal. If you hear the pump running (with the vehicle off, as it's much easier to hear it), then the problem may be external, or the pump itself could be bad.

You should be able to go to a parts store and most of them have a loan-a-tool program. See if you can pick up a pressure guage.

You may also want to call Isuzu and see if your problem could be related to the ECM reset. However, again the pump should run when wired direct to battery, without question.

It is only 2 wires going into your pump right? Remember mines a '92, so it may be different.

Steve

true, I did hotwire the pump and now I have it completly out of the asseemble and can hook it up to my battery, It starts up, winds down, then stops. I wait a while and then it starts back up again but then comes to a winding stop.

I have a spare pump lying around from another car and it spins and spins no problem. Too bad it does not fit. My question is now, where can I buy just the pump?

find a junk yard in your area.

www.car-parts.com

or

order up a whole new one from St. Charles.

If you gas gauage still works, I would chang the sending unit too at this time since it will most likely go out at sometime in the future.

Good luck and nice job trouble shooting!

-Ryan

great link, thanks

I replaced the pump and the fuel sender, and STILL, have the same problem!

I have not bolted the gas tank it up all the way yet, I was anxious to see if it would work.

I also get a check engine light, so I need to see whats that is I guess, this is a quagmire.

Even if I direct hot wire the fuel pump, it won't start for some reason, then, after a while it starts wirring up again. I may be acting premature.

Well it was up and running for 4 days, Now the Same exact problem all over again!!

Unbelievable, We had to have it towed.

The fuel pump apparently seems fried. I cannot hear any sound coming in from it.

Does anyone have some kind of theory on this?

I'm completley baffled, and somewhat angry from all the time and effort I spent on this vehicle.

Yes I put in a salvage yard fuel pump. It was working, how could it fail so soon? Good Lord.

Please somebody help me.

try swapping the fuel pump relay out with the horn relay

I've tried swapping other relays, why the horn? Does that one work differently? I'll do that, but I have to get to the vehicle. I had it towed to a friends house that lived closer. AAA charges 5 dollars a mile if it goes over 3 miles!

no that one dont work any different just didnt know oyu had already tried another
sounds like a ground issue or the pump is just no good the pump needs to be submersed in fuel or it will burn up quick fuel keeps it cool if you did run the pump before installing it in the tank this scould have caused pump failure

Sounds like I have to take it to a shop :(

Well the shop replace the fuel pump assembley with a brand new one from Honda.

After one week, we had a stalled car problem once again and had to have it towed.

It costs us 377.00 dollars to supposely fix the car and its still doing the same thing, seems the mechanic is baffled.

Here is the place I took it to:

www.uniqueautorepair.com

There coming over now to get the passport. Some passport, it can even leave the driveway. :(

Any clues?

Intake gasket
Fuel Pressure Regulator?

Heres something else:
The CEL came on after we took it home from the shop, we had it checked out and found we needed a cat converter, dealer/federal warrenty item. Not in stock, had to wait on that one, but they said it should not affect the starting or general drivability of the vehicle.

I thought I'd toss that in.

Help!

turned out to be a loose connection, I got screwed.

turned out to be a loose connection, I got screwed.

Where? What connection? :banghead: Talk about a total: :nutkick:.

Joel

Well not really a loose connection, but the mechanic said the pins at the connector to the fuel pump assembly (I'm assuming) were not making contact, which was part of the fuel pump assembly installation I suppose? He charged an additional 65.00 diagnostic fee on top of the 377.00 fuel assembley install, which I though was unfair, but what could I do? he had the car and keys, so we had to pay the bazard.

I think he should not have charged the additional fee because it was part of his original installation.

He did tow the thing 55 miles though.

So far so good, he warrents the fuel pump assembly for a year, so I have a warrenty at least...on that. Here's his websight so you all can send him nasty letters/viruses/whatnot:

www.uniqueautorepair.com