Stumped

[roverfiend]

Ok well i was having a problem with my tach not working properly.Figured alternator problem...pulled alt and had tested...bad regulator.....alt repaired and tested.....working wonderful.....still no tach but getting 13 volts at back of alt....before the repair the tach would work after a few minutes of driving and usually do fine unless at night..with headlights on tach would stop working when i stop at lights..then would have to drive for a while for it to work again....i also have a nasty miss that has developed.....it ran superb over the weekend....not a miss one..now..its insane....

replaced plugs and wires
seafoamed the intake
premium fuel
alt remanned by a very good shop i deal with locally

gonna pull the wires and test resistance to see if i lost one somehow as well as the plugs to see if i fouled one out.
I am at a loss here...also..just discovered i lose the tach when i put it into gear

96 d1 102k

 

[SteveA]

You may have an internal fault in the instrument cluster (IC). There is one wire from the back of the alternator (green I think, I'd have to look) that drives the tach. If that's connected properly at the alternator, take out the IC and check the connectors at the back of it. It's common for the tach to go wacko when the alternator is going bad, but if it just drops to 0 and stays there, I'd check the wire from the alternator to the IC.

Stephen

 

[joey]

I also could be the wire coming from the alt to the tach... it tend to get brittle and easily break...

sorry spelling suck bad headache.

 

[roverfiend]

well the two wires from the alt other than the main are white with green stripe and a yellow and brown.the white/green is a push on type while the yellow/brow is a screw on.voltage from the alt at the main wire is close to 13 till the tach comes up then it's around 14..same with the yellow/brown..at the white/green i have about 6 volts.i'm guessing that might be the tach lead?
also.does anyone know what the resistance should be thru the spark plug wires.i have what feels to be a dead miss..wires are new but if i take them back they will have to order replacements..just want to eliminate those if possible

 

[roverfiend]

well i changed the plug wires...the miss is still there.which leads me to believe it might be a valve problem...head gasket....injectors..or the ignition module itself.
the tach problem i havent tackled yet since i was tryin to sort the miss.

 

[joey]

You say you have a bad miss, is it giving you any CEL codes?

Or do you just hear a miss - this might be a bad manifold sounding like a miss.

after driving for a while, pull each plug and check to see if there are any differences between them.

I would get a mechanics stethiscope and with the engine running check each cylinder for the miss.

Check for any backfiring, also put hand on the exhaust pipe right after it idles down, and feel for sucking (cover tail pipe with your hand, gently not pressing) if contant pressure out all valves are good, if you get a hard suck in every second or so, you may have a bad valve or carbon issue.

 

[roverfiend]

no codes right now..but if i drive it it will give me missfire codes....1314-1316 are the ones i normally get.....it sounds just like a cylinder is not firing...you can feel it shake..you can really tell when you idle up..very noticable then...like a plug wire is off.....no backfires though....there is a tiny ticking noise coming from the right exhaust manifold gasket near the rear.....thats the only exhaust leak i know of...just checked the exhaust pressure like you suggested...the pressure feels constant...not sucking air back in

 

[joey]

Sounds to me (remember I am far from a LR expert) that you may have a bad coil pack. If you didn't have one of the plug wires installed all the way when you first changed them and one came loose, it can cause the coil pack to go bad.

This is not a cheap item, unless you can find one used. (of course then there is not warrenty)

 

[roverfiend]

thats the other thing i was afraid of.....that miss just appeared out of nowhere.it was running great after the intial plug and wire change..had great power and acceleration...and very smooth..then i fired it up one day and it was missing.....rats this sucks....

thanks for the help joey

 

[joey]

Like I said, I may be wrong... if you are near by a dealer, spend the $80 to have them check it before you go and spend a lot more on parts hoping to fix the issue.