97 Disco backfires over 2000 rpm
97 Disco backfires over 2000 rpm
Hi everyone,
It's been a while since I've been on here as my truck has been running great without any problems until last week. I've been away for the last 6 weeks and the truck has been sitting in a lot. Monday, I tried driving it home after letting it idle for some time and there was little to no power. Once on the road, it didn't want to go over 2000 rpm or drive faster then 25mph as it begins to lose power and backfire really bad. I crawled it back into the lot and tried revving the engine while in park and it still backfires.
I didn't have my computer with me so i haven't been able to read the codes yet but here is what I do know. I just replaced the spark plugs and wires less then 500 miles ago with Genuine rover ones and it was running great before I parked it. The fuel pump was last changed in 2007, about 63 - 65,000 miles ago. It doesn't have any problems starting up but wanted to see what everyone says on here before I head back to the lot tomorrow or Wed to run the codes and see where I stand.
If it is the fuel pump, I'll need one that has Advanced Evaporative Loss which isn't cheap so any advice would be great so i can get the truck out of NJ
Thanks
Jason
97 Discovery with 168,000 miles
It's been a while since I've been on here as my truck has been running great without any problems until last week. I've been away for the last 6 weeks and the truck has been sitting in a lot. Monday, I tried driving it home after letting it idle for some time and there was little to no power. Once on the road, it didn't want to go over 2000 rpm or drive faster then 25mph as it begins to lose power and backfire really bad. I crawled it back into the lot and tried revving the engine while in park and it still backfires.
I didn't have my computer with me so i haven't been able to read the codes yet but here is what I do know. I just replaced the spark plugs and wires less then 500 miles ago with Genuine rover ones and it was running great before I parked it. The fuel pump was last changed in 2007, about 63 - 65,000 miles ago. It doesn't have any problems starting up but wanted to see what everyone says on here before I head back to the lot tomorrow or Wed to run the codes and see where I stand.
If it is the fuel pump, I'll need one that has Advanced Evaporative Loss which isn't cheap so any advice would be great so i can get the truck out of NJ
Thanks
Jason
97 Discovery with 168,000 miles
Camel Trophy
Joined: Jan 2010
Posts: 4,245
Likes: 402
From: Traverse City MI
The sensor that will cut out at 1750 rpm is the Throttle Position Sensor, pull the plug and reseat. Try that a couple of times to make good electrical contact. You should have a Check Engine Light showing. Have it scanned for the MIL. When the TPS is at fault the ECU sets a fuel overrun cutout which is why you feel no power above 2k. The backfires are from what's left over in the cylinders when becoming lean.
Last edited by ihscouts; Nov 24, 2014 at 09:59 PM.
The sensor that will cut out at 1750 rpm is the Throttle Position Sensor, pull the plug and reseat. Try that a couple of times to make good electrical contact. You should have a Check Engine Light showing. Have it scanned for the MIL. When the TPS is at fault the ECU sets a fuel overrun cutout which is why you feel no power above 2k. The backfires are from what's left over in the cylinders when becoming lean.
Camel Trophy
Joined: Jan 2010
Posts: 4,245
Likes: 402
From: Traverse City MI
You might have one pending or if your scanner pulls up codes I'd be thinking the CEL bulb could be toast, it should've thrown something. The only other thing that will cause loss of power besides the two sensors mentioned is maybe the MAF or Cam sensor but it's rarer than the TPS. Do you have AEL on your 97? Tom lost the pressure sensor on his fuel pump which is inline with the TPS and it caused all kinds of weird issues. That's another sensor if you have AEL - Advanced Evaporative Loss - square charcoal can laying horizontal in engine bay.
You might have one pending or if your scanner pulls up codes I'd be thinking the CEL bulb could be toast, it should've thrown something. The only other thing that will cause loss of power besides the two sensors mentioned is maybe the MAF or Cam sensor but it's rarer than the TPS. Do you have AEL on your 97? Tom lost the pressure sensor on his fuel pump which is inline with the TPS and it caused all kinds of weird issues. That's another sensor if you have AEL - Advanced Evaporative Loss - square charcoal can laying horizontal in engine bay.
Baja
Joined: Mar 2009
Posts: 5,736
Likes: 230
From: south n.j. and ne va.
I will second scouts by saying mine did this, you can unplug it at the fuel sending unit and all should return to normal, it may trip harmless evap codes or something, I got a used fuel sender
With this I also had emission codes that would not go away for purge valve and a hard time filling gas
TPS and that pressure sensor share voltage, go figure
Being in NY I expect your fuel sendor looks like mine did , rusted and crappy
With this I also had emission codes that would not go away for purge valve and a hard time filling gas
TPS and that pressure sensor share voltage, go figure
Being in NY I expect your fuel sendor looks like mine did , rusted and crappy
Update....
Went out to the truck today and it started up without any problems and there were no codes either. I let it run for 30 min or so and then took it for a drive and no problems at all. My guess is that something got wet from all the rain NY received last week and was causing something to short out. I noticed I had a small leak in the sunroof last Monday and my only guess is the water coming in from this leak or somewhere else caused one of many things to short. Has anyone had problems like this before and besides fixing the sunroof, should I waterproof anything else on this truck to save me the hassle in the future? Thanks for all the suggestions and now to sort out some of the other problems which deal with my front breaks .
Went out to the truck today and it started up without any problems and there were no codes either. I let it run for 30 min or so and then took it for a drive and no problems at all. My guess is that something got wet from all the rain NY received last week and was causing something to short out. I noticed I had a small leak in the sunroof last Monday and my only guess is the water coming in from this leak or somewhere else caused one of many things to short. Has anyone had problems like this before and besides fixing the sunroof, should I waterproof anything else on this truck to save me the hassle in the future? Thanks for all the suggestions and now to sort out some of the other problems which deal with my front breaks .
Baja
Joined: Mar 2009
Posts: 5,736
Likes: 230
From: south n.j. and ne va.
Mine started intermittent then one day engine would nit run cause I lost TPS all together, no code
Keep an eye on it
I unplugged every connector I could and slathered with dielectric grease, can get it at parts store in rTV type tube, cheez wiz can, tub with brush
Wards off corrosion and water ingress, promotes continuity, I also did this on my lr3
If you do not have one I suggest an ultra gauge so you can watch live data on the sensors so when this happens you just look at the gauge and see what's off
Keep an eye on it
I unplugged every connector I could and slathered with dielectric grease, can get it at parts store in rTV type tube, cheez wiz can, tub with brush
Wards off corrosion and water ingress, promotes continuity, I also did this on my lr3
If you do not have one I suggest an ultra gauge so you can watch live data on the sensors so when this happens you just look at the gauge and see what's off