anyone ever run into this?. I have been chasing a phantom misfire for a long time now. Starts and runs fine but after a while it wants to die...tach flutters (bounces then drops to zero), etc...get out of the throttle and it idles fine and tach returns to normal. If its under the hood and gas or ignition related, I've replaced it. BUT...I was just reading on a Range Rover site that a guy had a similar problem and replaced the alt and it went away. Anyone ever had this on a Ru?

 

Bill

XT's are known for problems of this nature related to wireing harness issues around the door sills - being that the ECU is in the trunk the harness runs quite a distance to get to it. People have found stock crimp connections that had corroded or grounded out to the body.

 

If you think it's the alt then disconnect it. The engine will run for a time off the battery.

 

GD

Edited November 22, 200916 yr by GeneralDisorder

are we talking the main harness or something else?. I pulled the seat to get to the main harness but didn't see anything else. Did I plow thru and go to far? I found no connectors/splices crimps or visible breaks in the main harness...I haven't put the seat back in yet either tho....

 

Bill

You should probably ask for specifics over on the XT board. I only know of the problem by proxy - I've never owned an XT let alone one with that specific problem.

 

GD

The problem may be with the alternator due to excessive electrical noise and disabling like GD suggested is a good idea. Just remove the rear connector to the alternator while the engine is off and then start it up to see if the trouble clears.

did it...it didn't go away...

 

Bill

Ok. Another possible trouble area is bad bearings in the distributor for the shaft.

Wouldn't that be an optical pickup style distributor?

 

I don't think those can cause tach jumping but I could be wrong. Would likely set an ECU code too..... I would think.

 

Still - pull the cover and see what kind of play it has. Typically the needle bearing distributor's don't exhibit wear problems like the bushed units of old but you never know till you check.....

 

GD

thanks Coug, GD, but I swapped the distributor with another to rule out the whole thing. The only code the ECU's ever given me is 555

 

Bill

I wasn't aware of the disty shafts difference so thanks GD.

 

Have you tried replacing the ignitor module already? If not I would try that next.

I'm having somewhat similar problems with my '87 brat. Runs fine most the time, then just quits. Usually will start up after sitting a while. I checked the voltage and it all reads 14 plus everywhere I look. But my amp meter on the dash shows around 11 and after a while reads 12 after warmed up. I also sometimes have a problem starting it, It acts like a low battery(won't engage the selinoid), or the starter will crank slow. Usually in the morning. I have checked my connections but I may replace all the battery cables to rule that out.