need help with 97 disco
 

hello,
I am looking for any advice from any experienced landrover owners and/or mechanics. my 97 discovery is showing a random misfire in the number 7 cylinder. when the mechanic hooked the computer up it sited "excessive emissions" as the cause. Unfortunately this is all anybody can tell me and three shops have turned me away saying they don't know exactly what is causing this misfire. THe misfire is getting so bad that it will occasionally stal out at stop signs. any advice would be extremely helpful. other than this small headache i love the car.
burton

RE: need help with 97 disco
 

i had a customer with a smiliar issue on a non-rover product. do you happen to know if your vehicle has a mass air flow sensor? it would be somewhere around the air intake box or air cleaner...with some wires going to it..the issue that he was having was that he had a crack in the intake tube between his mass air flow sensor and his throttle body, with means unmetered air was going into the engine, and it happened to be leaning only one cylinder out, and ruining spark plugs, causing a very similar condition.

RE: need help with 97 disco
 

Remove all the spark plug wires from the plugs. Look into the boots and if there is any signs of arcing or corrosion the lead needs to be renewed. Especially check #7.

If all OK then you may have A valve stick issue.

RE: need help with 97 disco
 

Thanks For the Help. I checked around the air intake manifold and found that a rubber hose acting as an oil manifold vent which lead to the air intake manifold was badly cracked and dried. Replaced that and thought to have fixed the problem. It definitly helped but on a 50 mile drive yesterday i still had the same problem. looked for other cracks but could not find any. Any other suggestions?
Thanks again Burton

RE: need help with 97 disco
 

Did you check the plug wires ? A cracked PCV hose will not cause A single cylinder misfire code.

RE: need help with 97 disco
 

bait,
I was looking at past post today and noticed others with my problem and you adviced and fixed one persons problem by suggesting replacing the road speed transducer. do you think this would fix my problem. I know before i said that the computer was reading that only #7 was misfiring but this is coming from a mechanic who supposedly fixed my car two times and may not be completely true. any help would be greatly appreciated.
burton

RE: need help with 97 disco
 

97's were notorious for exhaust valve stick,also check your reluctor wheel and bent or misaligned teeth can do this also.just did a valve job on mine today:)

RE: need help with 97 disco
 

The classic signs of A VSS going bad are odd cylinder misfire codes 1,3,5,7. One or any combination of them. The computer gets A false signal from the sensor at highway speeds saying the vehicle is going 200+ mph. Since GEMS has a speed limiter programed in, it shut off one bank of cylinders. GEMS is bank fire so it Shuts off 1,3,5,7. Another symptom is your speedo jumping around. I doubt A VSS would cause stalling at idle.

How about them their plug wires partner, check'm yet ?

Rovertech,

Did you ream out the ex guides or put in the new style valves and guides ?

RE: need help with 97 disco
 

hey,
The wires were replaced three weeks ago. and the speedo does jump around and has twice stopped working all together. The car didn't stall while idleling but while coming to a stop. If it isn't the vss, and a valve stick problem how intensive is that job. thanks again for all your so far.
burton

RE: need help with 97 disco
 

O.K. another trouble.
I replaced the road speed transducer today and now i can't start the car. It just wines like the starter is not engaging. I tried taping the starter and that didn't help at all. Does anything need to be reset when something like that is changed? any advice is greatly appriciated.
thanks again Burton

RE: need help with 97 disco
 

VSS would have nothing to do with starting. Looks like you need A new starter. Speedo jump is almost always VSS. Nothing to reset, unless Check Engine light is on. Even if it is, it will go off after driving several times.

RE: need help with 97 disco
 

Bait,
I didn't think a reset was neccessary (Just a little wishful thinking). I found a starter online for $199 US. Would you agree that it is worth it to just replace the whole thing. I saw online that there was a fix kit that someone had used in a problem similiar to mine. DO you have any experience with those. My only experience with starters was rebuilding the one in my outboard and i swore i would that no matter how much it cost i would never try to do one myself again. hopefully you can confirm this so i have no problem spending the $200 plus labor. thanks for all your help.
burton

RE: need help with 97 disco
 

Starters, Alternators, And transmissions are not typically worth trying to rebuild yourself. Unless you do it everyday, your wasting your time. I have never tried rebuilding A Rover/Bosch starter. Are you sure the starter is spinning and not engaging ? As far as price, I don't really know. Check with RoversNorth, AtlanticBritish, Ebay, and your local auto parts store. They may be able to get you A rebuild.

It is probably A simple job for A rebuilder. But for you and me, it's just A pain in the ars.

RE: need help with 97 disco
 

to answer your question bait i ream out the exhaust guides and installed the carbon brake valves

RE: need help with 97 disco
 

bait,
I am pretty sure that it is spinning and just not engaging. I hear a whinning noise as if something is spinning real fast with no resistance. after i turn the key back you can hear the spinning slow down until it stops about 5 seconds later. have had a busy weekend so haven't been able to look at it to much. will probably try to replace it myself although i hear the space is very tight and involves a few profanities.
Thanks again. Burton

RE: need help with 97 disco
 

the bendix is broken inside the starter. a new starter will fix this problem, so will a new bendix but i assume a new starter is easier to find. the bendix is a little spring inside the starter that holds back a gear the cranks the flywheel when you turn the key. when the key is turned, the started turns on and the bendix is overpowered by the starter motor, causing the starter gear to engage with the flywheel gear. in turn, giving the flywheel a approximately 1/3 or 2/3 speed of idle. that is when your ignition and fuel kick in, completing the four stroke cycle.

1)Intake of Fuel and air, intake valve open, cylinder moves down, causing vacuum sucking in fuel and air,
2)compression of fuel and air, both valve closed, cylinder moves up, ignition fires 10 degrees before TDC (top dead center)
3)power, both valves remain closed, cylinder is forced down due to previous ignition,
4)Exhaust, exhaust valve opens, cylinder moves up and forces burned fuel and air gases (exhaust) out of combustion chamber.

basically what that says is that a motor is an air pump.