Engine/Transmission (1998.5 - 2002) Bad Fuel?

[stevegeorge]

On my 99 4x4, I have had to change the fuel filters at least once a day for the past 3 days. I cannot find any water in the canister, or have not found any dirt in the bottom. Fuel pressure is reading 14 @ idle, and 11 @ 70 mph, which is normal. The truck wil be running just fine down the road, then all of a sudden it will lose alot of power for a few seconds, then everthing kicks back in and goes to working fine again for a few miles, then repeats. I have tried purging air from filter, none present. After I change filter, everthing runs fine for 2-3 hours, then starts over. Any ideas? This is driving (literally) me crazy.

 

[Shovelhead]

Welcome Steve,

Does your BD P-N-P plug into the MAP sensor?

Several members have posted about loose or corroded connections at the MAP sensor plug. Most are cleaning out the plug and applying a little dielectric grease to the plug before reconnecting.

The act of opening up the fuel filter canister might be wiggling the wiring.

 

[stevegeorge]

Yes, it does plug into the MAP sensor I believe. Is it the sensor located behind the fuel filter? and in front of the IAT sensor?

 

[Shovelhead]

Yessir, that the one.

 

[stevegeorge]

Thanks ShovelHead, its off to my shop to clean the plug.

 

[Riflesmith]

stevegeorge,

What you are experiencing sounds like what happened to me recently. In my case it turned out to be the "fuel system" relay in the power distribution box under the hood. Swap some of the relays around in there and see if this cures your problem. Swapping relays around would certainly be a lower buck fix than changing multiple fuel filters! Good luck to you.

 

[kaffine krazed]

Where are you fuel pressure readings taken? Before or after the filter? If they are taken after the filter and are not droping from normal I would look somwhere else for the problem. What does the filter look like when you replace it?

 

[Chace TX]

Do you have a FP gauge?

I had a friend with the same problem. Fuel filter was plugged, and lift pump was only working part time. When the lp would quit he would loose power. I replaced the lp and the filter, he has not had any trouble since.

 

[Steve St.Laurent]

On your 99 it's easy to check pre and post filter fuel pressures - that's the two ports in the top of the filter head. I had a bad load of fuel once and it acted just like yours is. I'd check the fuel pressure differential first though to be sure. With a new filter you should see no drop at all across the filter, when I had the bad fuel load I went to a 2 psi restriction across the filter within a couple of miles and after changing the filter the same thing happened again. Here's a thread on my fuel problem along with what I did to correct it - https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=12655 .

 

[Riflesmith]

Originally posted by stevegeorge

On my 99 4x4, I have had to change the fuel filters at least once a day for the past 3 days. I cannot find any water in the canister, or have not found any dirt in the bottom. Fuel pressure is reading 14 @ idle, and 11 @ 70 mph, which is normal. The truck wil be running just fine down the road, then all of a sudden it will lose alot of power for a few seconds, then everthing kicks back in and goes to working fine again for a few miles, then repeats. I have tried purging air from filter, none present. After I change filter, everthing runs fine for 2-3 hours, then starts over. Any ideas? This is driving (literally) me crazy.

From reading his post it does NOT sound like a fuel filter problem.

If you have a filter plugged up with bad fuel would "everything kicks back in and goes to working fine again for a few miles, then repeats" even be a possibility? I don't think so. I think this member is dealing with the same electrical problem I experienced a week ago. It is a bad relay causing his lift pump to shut down. When you are having the problem, what is your fuel pressure reading? Since fixing mine, I have not had a repeat of the problem. Lift pump(s) are running fine.

 

[Shovelhead]

Update... ..... culprit... ... Corroded MAP sensor plug.