I hear the frustration. Put a summary of this thread with all the things you have done in the "discovery 1" section of this site and you'll get more/better help. Wouldn't hurt to link to this thread either. State the current status and whether any check engine light / DTC codes are present. Year of truck too (best to put that in your signature so everyone knows all the time). Do you have an OBD dongle and app to read sensors and fuel trims?

Fellas with far more experience than me will offer help I'm sure. That is how I keep mine on the road.

 

Thanks Walt I'll do that.

 

Ok, an update with a guarded happy ending. After giving the Disco a time out, I went back to trying to figure this out. I did retest all the wires to and from the sensors for voltage and continuity and all that seemed ok. Retested the fuel pressure and saw that it was up around 40 PSI. I also noticed that there was a lot of fuel in the oil pan. Drained that (very watery due to fuel) and put in fresh oil. Started to think timing, either chain jumped (unlikely) or the ignition timing. Did a compression check, and all the jugs were around 150psi well within 10% of each other, so I started to feel good about the valve timing at least. I removed the fuel pressure reg. and noticed fuel dripping from the vacuum fitting. AH HA! replaced that, and put in yet another fresh set of plugs, but before I started it I decided to siphon all the fuel and put in new. I had to take out the pump to do that, and while that was going on I noticed the fuel was very amber colored, and didn't smell right. Another AH ha! Put in new gas with a bit of Sea Foam and Viola, she fires right up. Was idling at around 1800 RPM, but after hitting it with robertf's GEMS Utility it settled right down to a nice smooth idle. I haven't tried it yet today. Hopefully I haven't tooted my horn too eary.

Check the simple stuff first.

 

Oh yes , Walt I recounted this whole episode on the Disco 1 section, but somehow I deleted it rather than posting it, and don't feel like retyping it right now. Thanks for your encouragement. Hopefully this will help someone else out of a brain eating jam.

 

Glad it worked out. Sounds like it was simply bad gas. Any idea how long it had been in the tank before you bought the vehicle?

Yes, check all the simple stuff (and low-cost or free stuff) first.

 

Well it was short lived in a way. I started having the symptoms again, but this time I got the P1447 code. I went around back and unplugged the pressure sensor on the top of the tank and it runs perfect, but I have a CEL. I took the pump housing out and looked it over to see it maybe I did something to it the last time I had it out, but I saw no obvious signs of damage. I did however have problems with the gasket as it seemed to have swollen up some and would not get back in it's hole. It's a new one, since there was none there when I bought the truck. I put it in the freezer and went in and watched a couple episodes of the Sopranos. After that it went in a lot easier.

Anyway I have read as much as I can on it and It seems like I may have to replace that housing. It looks relatively new and has an Airtex sticker on top, so somebody has already shelled out the big Dinero for it in the past. I think I will just drive it like this for a while.

I have unplugged and capped the plenum vacuum port and also the disconnected the line just before the purge valve in hopes that it will vent itself when needed. Maybe the bad gas goofed up something in that system.

 

The fuel tank pressure sensor is tied into the throttle position sensor circuit on a 98, I wouldn't disconnect it. I would check the next harness connector up from it for corrosion/connection, it's not that dry in Florida. It's over-fueling but no code. The sensor for the ECU coolant temperature (there are two, one for the dash gauge, one for the ECU) is usually the culprit, telling the ECU it's colder than ambient and the ECU compensates by lengthening the pulses, much like a choke, to warm up the engine. Most of the time it gives a fault code but it's a 22 year old Rover, anything goes. It's a cheap and common part and I believe mine failed at around the same mileage..... but I got a code.

 

Thanks scouts, I'll check the connectors. Looks like there is one near the LH rear wheel well, then another up behind the fuse box, and yet another in the engine compartment behind the washer fluid bag. I can see that the red wire looks like the common connection to the TPS, providing power I would imagine. I measured the power at the red wire back there an it was 5 volts if I remember correctly. I get the 1447 code and another one I can't remember at the moment but it's something about the purge circuit, which I attribute to the plug being disconnected. Anyway, with it plugged in the vehicle barely runs. Unplugged, runs great. I did not want to fry the TPS due to the short. So it's staying unplugged til I track down the short. I have pounded on the Purge valve, tried running with that unplugged, etc,. No difference. I will replace the valve, since P1447 points to that. I can read the ECT on my OBD and according to that, at 75 MPH on I 95, it's just under 175. That would lead me to believe that sensor is working OK. Sitting at idle with the A/C on, it sits around 180ish. It's not to hot down here right now, so it's not much of a stress test. Also, the readings for the TPS seem pretty smooth. The IACV seems to be working fine as well. I still don't see any feedback for the MAF, but according to the info I can find, if it's not working, the engine stops, much like a malfunctioning Ckps, so I guess it's doing OK.

I am becoming more and more convinced, the devil has taken residence in this wiring harness.

 

Had this problem, burnt out ECM, solved with used ECM however you must buy with matched alarm module so your key fob will operate door locks. Try Roverguy has good prices. Good luck

 

As an update, I replaced the AEL purge valve with that Volvo equivalent and it seems to run great most of the time. To answer your reply on the ECM Boxter, I did in fact acquire a different ECM from a company on Ebay when I was in the parts throwing mode. At first I installed it and the vehicle would not start, but I applied Robert f's tool to it and it worked perfectly. I did not have to get another burglar alarm brain. The tool will allow you to pair the two brains. My only complaint I have with this set up is, I get a code for EPROM error that I can't get rid of. Also, it doesn't seem to run any better or worse than the original brain. I will probably just put the original one back in. I also am still not getting any feedback on my OBD reader for the MAF. It has a flatline as far as airflow. That's on both ECM's. I have checked the continuity of the wiring and it's good. I have 4 different MAF's ( the one that was in there when I bought it, no name, A Lucas one it's on there now, A cheapo from ebay I don't remember the brand, and a Wagner one that I got from the parts house.) Like I said it runs fine now. I do get a weird occasion where it will start and idle low and crappy, which is why I unplugged the pressure sensor before. I am running it plugged in and it runs fine MOST of the time, except for the occasional starting up and running crappy stint. I have noticed the last time I did it, I didn't do any wiggling or jiggling or unplugging, I just shut it down, restarted and it ran fine except a higher idle. I just hit it with the GEMS tool and it's back to normal. I do see that my bank 2 downstream O2 is not responding correctly (1.20 volts all the time) so the next thing will be those. Maybe that'll get everything baselined so I can get this thing semi reliable. Only other issue is a bit of death wobble, but I thing I will have that licked soon.