I have a confounding problem with my 96 Disco (102K Miles). If I'm driving for a prolonged period at 50-70 MPH, the engine will periodically start misfiring. It will lose about 50% power for about two seconds every two seconds. I must look like an idiot driving down the road, trying to accelerate during the two seconds that I have power, then decelerating for two seconds, plus it is extremely difficult to maintain a speed of above 50 MPH when this happens.

The problem is that there is no rhyme or reason to when it decides to start misfiring. Sometimes I can drive four hours without a problem, and sometimes only 15 minutes. Sometimes the misfiring last for hundreds of cycles, and sometimes just one. The check engine light has come on multiple times, and the dealer is stumped. The code is for 'multiple misfire,' but the dealer cannot reproduce the misfire and simply cleared the code and told me to bring it back when it does it again. The problem is I can't make it misfire on demand.

Its extremely frustrating and I'm going to get rid of this lemon as soon as I can. One sidebar is that I had the entire exhaust system replaced back in 2000, including all O2 sensors, I believe. This dealer was extremely shady and always did poor work. From what I have read, possible sources of the misfire could be anything from sticking exhaust valves to bad O2 sensors. I wonder if any more of you have had this problem and what I might be able to do about it...

 

In order to not play a guessing game with what is going on with your truck, you have to wait for the check engine light to stay on and not go off. Is the only code stored for a multiple misfire? I find a hard time believing that. How many miles are on your truck? Let me know.

 

Whoday,

Have the Dealer replace the road speed transducer, on the tranfer box. Common problem with exact same symptoms. This is assuming your from the States (USA) and have A petrol V-8 ? About $110 US plus labor. Or find A competent dealer.

Bait

 

joerover-- The only time that the check engine light stayed on was when I took it to the dealer, who told me the code was for multiple misfire, and that there were "multiple ways we could spend money on this." This, of course, made me cringe. I have 102,000 miles on the truck.

Bait-- I will try replacing the road speed transducer, its certainly worth a shot. I'm just not in the mood to spend $2,000 for a valve job. I am in the US, Ohio actually, and the V-8 runs on petrol.

 

the same sorta thing happened to me this moring, only it did it once for like 2 seconds ane i was accelereting from a stop sign, doing about 20-30 mph. do you thing the engine still being cold could have something to do with it?

 

Bait, thank you my friend.

I replaced the road speed transducer and the truck is now running like a top (well, at least like a '96 Disco should). I have taken four trips of over an hour each and had zero problems in the last two weeks.

The dealer was very reluctant at first on replacing the transducer, and kept asking me why I wanted to do it, and I just told him that I had done some research and knew some people who knew about '96 Discos. The funny thing is that when I picked up the car, he told me that it would probably solve the problem. Quite a change of a tune there, which leads me to believe that he realized the transducer was indeed malfunctioning and that you were right all along.

It's so nice to be able to drive around without having the worry of a breakdown anymore. Thanks again Bait. You da man!!!!

 

Bait is right on the mark on this one. I have a friend who had the exact same behavior, and it was the VSS. I am interested to know if this solves it, as one of my friends at the dealership suggested the VSS as a possible culprit in some cruise related issues I have had.