I get codes for random missfire and cyl4 and cyl8 missfire. I took it on a short road trip today as I need it over the jeep, ran reasonably well on the way there, on the way back it was horrible, you have to go either 75mph or struggle at 45-55 with loads of stumbling, snorting and popping. When I start it up it revs up to 2k, then down to 1800 till it warms up some, once in gear it goes down to just below 1000rpm, but will hunt from time to time, usualy when its missfiring. I know its idle issues got worse when I mess with the TPS, I put a small hole in the back side of it and hosed it down with CRC electrical contact cleaner, just made it worse. I am at the point of just dumping it and buying an old Jeep CJ with a simple motor and NO computer BS!If it was only possible to legaly set up the rover v8 to run without all this crap on it. I love the Discos look, espicaly with the brush guard and spot lamps, but if its not gonna run right without dumping major $$ into figuring it out. Heck, the nearest rover shop will cost me over $100 in fuel to make the trip. I dont have the income for this, let alone the parts to try to fix her. I am so depressed and pissed off.

 

Mine has new wires, had new champion plugs, but I pulled them and put the bosch platinum back in that came with it for now. I have check for any vac. leaks, didnt find any. Whatever it is, its getting worse the more I drive it. If its valves ect, then its defintaly gonna get sold and I am gonna take a major bath on it. Its super clean, the frame is almost totaly rust free, only a few spots of surface rust, body has 0 rust. Its also a AZ rover, having come to the snowy north just recently. I wonder if the heat is getting to the coil packs and I am getting weak spark under a load, like today pulling a trailer. I need a simple V8 or I6 with a carb, distributor and wires/plugs, or a diesel.

 

I pulled the IAC stepper motor, was pretty gunked up with carbon deposits. I cleaned it up good with carb cleaner and the wire wheel in my dremel. However the plunger thingy unscrewed messing up the setting.Thus it would wouldnt stay running at idle. Thru trial and error, I managed to get it back to how it was running. Still revs way up as the TPS is still acting up, but once it idles down in gear, its much smoother. I doubt this will fix the stumbling/power loss on the highway, but its one less thing screwing up. Anybody got a known good TPS for $25 shipped to me. That was the prices I was getting, but cant seem to get ahold of the person now. I can paypal right away if you have one. Gonna change that first and go up the chain. Mike

 

Not sure if there is anything I can add but my '03 (78kmi) has now developed an odd intermittent stumble which only occurs upon an up shift to second and third gears, not at idle and not at constant speed, and not if you lightly depress the thottle. This started immediately after I had the transmission service performed. The truck has had techron run through it from day 1, freshly cleaned K&N.

Is there any transmission sensor/feedback that can effect the engine so as to cause a miss under select conditions??

 

This weekend I tried the seafoam through the vacuum line trick, as well as searching for vacuum leaks.
I fixed a small vacuum leak in the breather hose, but did not get very far.
It is running a little smoother but still has the same problem.

It also seems to be tied to underhood temp, being worst when the under hood temp is the highest.
This manifests itself as running rough after long periods of idle, a short parked heat soak, orprolonged low speed driving.

This all makes me think of electronics that are sensitive to temp.

Brings back the question.

Is there a way to diagnose the coil pack, and have others had trouble with these before?

Thanks for the help!

Mike

 

Could this be an injector going bad?

Has anyone had injector problems with these trucks that get worse as the underhood temp increases?

Thanks,

Mike

 

I think I figured out what was wrong with my wife's '03... cheap gas. Been hiccup free for a week now but mine doesn't sound like the same problem (or at least not as severe) as you guys are having. It's on autotrader now if anyone wants to look at her (48k great shape). My wife has decided she wants something that doesn't make her feel as bad at the pump.

 

I tried a coil pack, and it still did not fix the issue.

Sometimes it runs great, but other times it really runs like crap.

Does anyone know about either injectors going bad or some other ideas?

Do these trucks have a knock sensor? I have a small exhuast leak and thought the noise might potentially triggera knock sensor.

Thanks,
Mike

 

I really haven't gotten into this particular post so far, but as it grows, it seems like a lot of prople have code issues and no one has found the fix yet. Shout if you want some help.
Mike

 

PLEASE HELP!!!

(Can you hear the shouting?)

Thanks for the help!

Mike