98 Disco is having the following stalling trouble:

Starts fine, and I hear the fuel pump click once to pressurize. Runs OK for 1 minute, sometimes as much as 8 minutes, but then loses revs/power and stalls out.

Does the same whether idling or running.



New fuel filter made no difference. Has a fairly new air filter. Gas tank full.

The fact that it starts fine makes me think it isn't a fuel pump problem. And I was able to repressurize the fuel system after installing the new filter.

Not sure what to troubleshoot next.

Other pieces of information: Problem seemed to start when gas tank got below a quarter tank. As far as a I can tell the speed is reading accurately.

Help on next things to check much appreciated.

 

Try with gas cap loose. If tank venting isn't working then pump can't move the gas as easily.


Check fuel pressure at valve on passenger side fuel rail, looking for 32-34 when pump is running. Pump sits in gas and is cooled by it. Can go bad if tank run very low frequently.


Clean out PCV system and IACV when you have the chance.

 

all of what Buzz said, and if possible get a fuel pressure gauge you can leave attached to the fuel rail.....when it quits you'll know if the pump had given up or not, are there any cel codes ?

 

Ok, finally got back to this. Thanks for the advice.


Fuel pressure sat rock steady at 31 when idling. Sounding a bit rough, but never stalled with 15 minutes of idling. Sat and revved to 2-2500 for minute or two before turning off, and pressure dropped to 30, but still pretty steady. rev's seemed to be bouncing around, but honestly could of been me leaning over peering out at the fuel pressure gauge.


So assuming that fuel pump/pressure is not the problem here. (Is 31 a problem? Not quite 32-34, but not bad either. And as I said, very steady when idling.)


Working to get the IACV off without stripping those f'ing little bolts tucked under just so!


For cleaning PCV hoses (and oil separator?), would love newbie advice on identifying which hoses I'm going for. Looks like a 98 DI has two. One thicker one -- is that the hose just to the right of the IACV? (that has a 90 degree bend and dives down near the oil cap/filler tube to the driver side valve cover?). Where is the other one? Off the passenger side valve cover?


Finally, before this all happened I was getting codes 1178 and 1176. Will clear and see what comes back.

 

fuel pressure ok for now,
you are correct on the hoses, and clean the iacv carefully.....dont turn it in orout....just clean it.....
fwiw.....I had those same codes, chased them for a long time...ended up needing a new maf sensor......you can try cleaning yours first though with maf cleaner when its cold before start up

 

Tried some MAF cleaner, and has gone from bad to worse. Starts, but now stalls pretty much instantly. Will look into MAF prices -- grrr. Is there a way to tell definitely if that is the problem??

Will still clean IACV and hoses before going further on MAF, but seem to be taking steps backwards!

 

Did you follow the MAF cleaner directions? If not you can destroy the sensor, I have some used ones

How is your voltage?

 

From the RAVE - about dead MAF sensors


As there is no default strategy, failure will result in the
engine starting, and dying when it reaches 550
rev/min, when the ECM detects no MAF Sensor
signal. The fault is indicated by illumination of the
malfunction indicator light (MIL) on North American
specification vehicles

Please don't buy a new one from a list price supplier. Used or removed with your own hands at the boneyard. Nice spare to have as well. I recall seeing prices of $1400 for them.

 

Well, MAF was reading nothing. Replacement MAF, and a fuel temp sensor, and the beast is running "code free" for the first time in a while.


Now can turn to various leaks, and the persistent slow battery drain.