[AllanC]

Does the engine stall happen when the fuel level is below 1/2 full? Since your fuel level at displayed on the gauge is erractic, it is difficult to know the level. You might try and fill the fuel tank completely. Drive the vehicle and make a hard stop and vigorous left and right turns. If there is no stalling then the problem is that when the fuel gets to a certain level (less than 1/2 tank) fuel is moving away from the reservoir and the pump inlet is uncovered and gets a momentary shot of air which disturbs the fuel supply.

What would cause this behavior of fuel leaving the reservoir and causing a momentary stumble? From a picture in a Dakota service manual, the pump is mounted vertically in the tank. On the bottom of the pump and very close to the floor of the fuel tank there is a round filter assembly. If that has become dislodged for any reason, a low fuel level in the tank will allow the liquid fuel to move away and uncover the pump inlet.

As for the problem of the fuel gauge, the fuel sending unit is mounted on the side of the pump assembly. I suspect the pivot pin for the float arm is worn and allowing the arm to make only intermittent contact with the variable resistor circuit that drives the fuel gauge.

In both cases the fuel pump module will need to be removed and the pump inspected. The easiest solution and also the most expensive solution is to replace the fuel pump. But I would somehow get a fuel pressure gauge mounted in the engine compartment and snake the fuel tester hose such that you can see the fuel pressure while you are driving. Then when the stalling occurs you can verify if the pump is losing pressure. If the pump maintains pressure when the stalling occurs then it is NOT a fuel pump problem.

 

[lalunette]

You might try and fill the fuel tank completely. Drive the vehicle and make a hard stop and vigorous left and right turns. If there is no stalling then the problem is that when the fuel gets to a certain level (less than 1/2 tank) fuel is moving away from the reservoir and the pump inlet is uncovered and gets a momentary shot of air which disturbs the fuel supply.

Well, this is certainly something worth trying...

Payday is this Friday so I can fill the tank and have a go at what you suggest !!

I will report ASAP.

Cheers !!

BTW, while looking up the cost of a new fuel pump, I came accross this...

http://www.canadapartsonline.com/search/?N=0&Nf=price6%7CGT+.01&Nr=universal%3A0&PN=0+5807&VN=4294964648+4294964611+4294967143+4294964926+4294966029&Nr=universal:0

Could this also be part of the problem ??

Cheers !!

 

[AllanC]

BTW, while looking up the cost of a new fuel pump, I came accross this...

http://www.canadapar...&Nr=universal:0 Could this also be part of the problem ??

Fuel pressure regulators are very simple and reliable and durable. On all of my Chrysler built fuel injected vehicles I have gone many, many years and miles (250,000 miles over 20 years) without ever having a fuel pressure regulator fail. I doubt that the fuel pressure regulator is causing this stalling.

 

[Bob Lincoln]

I haven't taken mine apart yet, but on many vehicles, if the pump inlet 'sock' falls off, the check valve is non-functional, and it won't hold fuel in the pump during turns.

Lately my truck reads erratically when below half full - reads low and can pulsate up and down up to 1/4 tank every few seconds. I was hoping to replace the original pump proactively, but winter is creeping in fast here.

 

[lalunette]

Well, sorry for the slow reply but the Dak no longer stalls !!!

Part of my Dak winter prep was finally getting the right size (aka bigger) battery for a V8 Dak, as well as putting in new + and - cables between the battery and engine.. and unwittingly solved the stalling issue.

Here is what I think was happening...

1) the battery-engine connection wasn't as powerful as it could have been
2) when the RPMs dropped the alternator was no longer producing enough juice for the engine
3) the battery could not make up the difference
4) the engine stalled

Does this make sense ??

 

[Bob Lincoln]

That could be.

 

[awyseguy]

Most vehicles I've seen will run fine without a battery installed.. Perhaps your old battery had a cell that was going bad.. and was showing an occasional voltage variation that was confusing the computer.. OR you could have had a bad ground that you accidentally fixed.

 

[Bob Lincoln]

You cannot run without a battery in cars since the 1980s, without blowing up the electronics. The owner's manual and service manual warn you NOT to disconnect the negative terminal with the engine running. A floating ground causes voltage spikes that damage the electronics. And the impedance of the battery is factored in.

 

[awyseguy]

Thank you Bob.. I was using 1 battery for moving 2 of my Dakotas around one day.. I didn't realize you weren't supposed to do that any more.. I would start with the good battery.. pull it out and put in the other truck.. and put the run down battery in it's place..

 

[lalunette]

You cannot run without a battery in cars since the 1980s, without blowing up the electronics. The owner's manual and service manual warn you NOT to disconnect the negative terminal with the engine running. A floating ground causes voltage spikes that damage the electronics. And the impedance of the battery is factored in.

And that is why I love my '91 Lada station wagon so much... no electronics to speak of.