Waylayer

Ol lady backed truck into ditch, still in ditch cause now it stalls. Had it run longer after leaving it sit for a couple hours but then runs for a sec then stalls. when starting with pedal to floor it starts reving up then quickly dies. The ass end is in the ditch, could it be a weak fuel pump? most every thing else is not too old and never had this problem before with 227k miles. v6 3vze motor.

rworegon

Fuel tank about empty?

MaK92-4RnR

Fuel tank empty? lol

Waylayer

I dout it, but if it is im gonna feel like a horses rear end. Actually hope its that simple.

MaK92-4RnR

lol you'd be surprised.

Waylayer

Its at a point now where its more level and stalling.

scope103

"Starts then stalls after a few seconds" sounds like an AFM problem. The fuel pump is powered when you switch to start, but after you release the key the fuel pump only gets power if the air flow meter says air is flowing.

It's simple to diagnose: jumper B+ and FP (which forces the pump to run all the time) and start it. If it keeps running, there's your problem.

And if that's the case, do get it fixed. If you have an accident that breaks a fuel line, do you want the fuel pump to keep running?

Flash319

COR relay / fuel pump problem

Waylayer

thanks, it was one hell of a trip but got it to a garage today. we will see whats up. Ill update.

Waylayer

got it fixed....it was a relay behind dash. part ordered would have been 150$ but got a two at junk yard for 10$ and waabaa shes up amd runnin, more like moping i guess.

MUD-LIGHT

What relay was it I think mine is doing the same thing.

scope103

I can't say for sure, but the most likely relay to cause that problem is the Circuit Opening Relay. (COR)

Don't guess; start with jumpering FP to B+ (as described earlier). You can waste a lot of money and time replacing parts at random.

MUD-LIGHT

Sorry Im kinda a newb whats the B+

MUD-LIGHT

I don't think its the fuel pump because it starts up right away and will idle also idled in gear but when you put a load on it, it stalls. I know how to drive so that's not it lol. So that tells me the fuel pump is good right? So you say to check the COR is there an easy way to test it? Buddy said something about a sensor on the tranny? Also I was thinking maybe something with the MAF. I really appreciate the help. Also the truck is a 95 T-100 3.4l

Aka paco

Hey guys not meaning to thread jack, just didn't know if i should start a whole new thread considering i'm having a similar issue..

My truck died and left me stranded not to long ago, it would start up and die after a second or two, sometimes i can let it sit for a few hours and it will start up and run for a 5 or 10 mins, after that it will just crank then die..

Anyways I jumped the relay via the port under the hood everyone suggests, and had a multimeter to the fuel pump wiring, no power, tried it without jumping it, no power..

So finally i took the jumper wire off and had everything normal, except this time i pushed in the door flap on the AFM and my fuel pump wiring showed power getting to it, as soon as i let the AFM flap closed it went to zero again, open it up and power..


So i'm assuming this means my AFM is bad? i'm confused though jumping the COR relay did nothing? should i replace the AFM and COR relay as well? or is my COR relay ok?

scope103

If you get 12v (about) to ground at the FP connector when you push the VAF flap open, then the VAF is working and so is the COR (at least one of the windings). Of course, when you get 12v at FP the Fuel Pump should run. If the fuel pump runs, then jumpering FP to B+ has to also start the fuel pump. (If you don't have 12v to B+, then nothing will work.)

Do you have 12v on the B+ connector with key-on? Does the fuel pump run when you jumper B+ to FP?

Aka paco

Thanks for the reply, I guess I need to re verify the way I jumped connectors. my truck is at a friends house so I won't get to mess with it till Thursday ..
Thanks for verifying my vaf is probably good, I was thinking that was the problem, but I do get 12.55 v at the fuel pump connector when the flap is pushed and key is on..

Gonna try and narrow it down this week. I don't mind replacing parts, but definitely hate to buy parts that don't need replaced!

Anything else it could be besides those three parts?

Thanks

Aka paco

Well I decided to replace the fuel pump only because i had the bed off already and figured at least that would eliminate the problem and i shouldn't have to worry about it again. I decided to put my Air flow meter back on and try jumping the relay again, i used the B+ to FP connectors, and my car started up and ran fine, i drove it to the store and let it idle for about 15 minutes everything seemed good.

after it was running for awhile i was not 100% convinced the problem was my relay, only because mine looked new and most failed ones i've seen pics of had at least a slight visual indication once opened, my interals looked good..

so while the car was running i removed the jumper wire, and it stayed running, i drove it 18 miles after that with no problems, not even on the interstate..


My overall guess is that the fuel pump was on it's way out, and my AFM and CORelay are fine? guess i'll keep my jumper wire handy in case i break down, hopefully the fuel pump resolved the issue.

pete c

I am having this problem with my motorhome. It is a 90 toy C&C 3VZE auto. It starts, will idle for a bit, but, as soon as a load is put on it sputters and stalls.

I am going to replace the fuel filter first, since it is due anyway.

Fortunately, I have another 90 toy pickup sitting in the drive (a friends RV that I am doing work on), so, I can swap the above mentioned relays. Could someone help me with locating them? And where is the FP connector mentioned earlier, so I can jump it.

pete c

Had to hacksaw the old fuel filter on one side. The old filter's flow seemed
fine.

Crap.

When I removed the filter, there was pressure. How much, I don't know. Anyway, I
hooked up the new filter and let the output disconnected. It is not building
pressure or flow. No audible sounds from the pump area.

I disconnected the pump wires. I have 5.5 VDC with ignition on. It goes to 9*
volts when turning over.

This has me kinda stumped.

I think the pump is bad, but, I'd rather not spend 130 bucks (price of pump) to
find out.

Is it OK to put 12V straight to the pump at the connector? Is polarity important
for testing it?

Will my charger with a 1.5A output be enough to test the pump?