engine code questions

Hoot

Well-known member
Apr 19, 2004
234
0
52
Bloomfield twp, MI
I have been getting coded off and on for the better part of 7 or 8 months. its a 96disco. the codes are P0300 random multiple misfire and p1316 excessive emissions due to misfire i have changed the plugs, changed the wires twice, now i have magnecors. I am fearing the need of a valve job.

what else should i check, before i have the engine torn into? and what can i check myself without incurring the dreaded diagnostic fees. I'm not trying to downplay or discredit the worth and valuie of a good professional rover mechanic. I am just not sure i can afford one, especially since i have a weeding to pay for in less than 4 weeks.

further compounding my headaches is the fact that i have to pay the yearly registration fees and have the California Smog check done. I am pretty confifdent i am going to fail the test based on my "excessive emissions" code.

i may be up shits creek without a paddle but if anyone can ofer up somehelpful suggestions i would appreicate it.

p.s. Vive Le Discoweb, glad it is back up. I dont think i could have gone another week, without discussing my mechanical woes or reading others.
 

Robbie

Well-known member
Apr 20, 2004
1,463
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NOVA
how many miles on the truck and when were the O2 sensors last changed? not sure, but something to look into. course, O2 sensors are $90 a pop, so not like you want to just throw them at the truck without knowing if they work or not.
 

Hoot

Well-known member
Apr 19, 2004
234
0
52
Bloomfield twp, MI
robbie, i have 76,000 miles on it. as far asi know the O2's are OE. not completely sure though since i've only owend it a year. but i have 3 years of service records form the previous owner and i dont think they were changed while they had it either.

Would the O2 sensors cause the enigne to throw a random misfire code?
 

Robbie

Well-known member
Apr 20, 2004
1,463
1
NOVA
no, they shouldn't. just read the excessive emissions part, and thought maybe you were getting too rich a mixture or something. they shouldn't have an effect on misfires (i don't believe?). what year/model is the truck?
 

Robbie

Well-known member
Apr 20, 2004
1,463
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NOVA
do you feel the misfires and when you clear the codes, they come back right away?

if you suspect sticking valves, might not hurt to run some Seafoam through it. I have never used it, but quite a few people on here have used it with success. i even think there is a thread on the new board about it, so you can find it here.
 

Hoot

Well-known member
Apr 19, 2004
234
0
52
Bloomfield twp, MI
no i dont feel the misfire at all, nothing, not a hickup. and after i clear them i dont get them immeadiately after. sometimes it'll go a few weeks or a few months before i get the code back. it always happens within 1 or 2 miles of having started the truck after having sat over night or for at least a few hours. it has never happened after it has been warmed up or when i am driving on the highway.

and i have used the seafoam. it didnt change the misfire issue. cleaned out some carbon i think as the tailpipe smoked up a storm. it also lowered and levled out the idle a bit.
 
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anthony

Guest
a have a 96 and have had the same problem except my codes are p0301 and p1316, i have read quite a lot about the p0300 w/the p1316 usualyy turning out to be valves, on the old site there were a ton of posts about your specific codes. if it is exhaust valves the seafoam wont reach them before getting burned up, i read but have not tried yet, to slowly pour a 2 liter bottle of water through your intake and it will reach the exhaust valves. works because the water turns into steam instead of being burned up and carbon is water soluble. hence, the steam is forced out through the exhaust valves taking the carbon with it.....i dunno, it does make sense though! might want to try this out, if you do please post the results!
if you end up needing a valve job i suggest taking the heads off yourself and taking them to a machine shop and letting them do the hard stuff!
here is a really good site for valve jobs! www.robisonservice.com-servicedep-pdfs-car


welcome back d-web!!!!
 
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anthony

Guest
naa,
i just keep resetting the light-piss on it! i believe my issue may be in my coil pack, just have not gotten around to checking it....mabe i should go do that instead of sitting in front of this computer!
mabe the archives will be added soon and you can search for p0300, go to google and type in land rover forum, go to first hit and search their archives...mabe that will help!
sorry dont have definative answer, just rule out all other causes before you do a valve job-

have a compression check ran on it!
 
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agro1

Guest
I have the same problem, with the same codes being thrown...'98 Rangie 4.0. It only runs "rough" on a cold startup. If I put it in reverse or drive (with my foot on the brake), the motor runs really rough and lugs at idle. Then smoothes out as it warms up. I've checked the plugs wires at the plugs and they look clean, but the wires themselves are old and cracking, so I'm hopeful it's the wires arcing and need to be replaced. I'd be pretty pissed if it already needs a valve job...UGH.

Is the coil pack where the plug wires all meet at the back of the motor ? Is the coil pack the same thing as the distributor cap ??
 

Hoot

Well-known member
Apr 19, 2004
234
0
52
Bloomfield twp, MI
argo,

have you replaced the fuel filter? mine used to do the same thing, only occasion though. replacong the fuel flilter cleared up that problem.

also i have a set of wires i had ordered for my 96 D1 from rovers north. I only ran them for about 3 weeks. I still had the codes beig thrown so i bought magnecors to make sure that teh new wires werent bad. I still get the codes. so it wasnt the wires. so they are good. if you want them i can sell them to you for less than i paid.
 
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Louis

Guest
I recently cleared a barely noticeable misfire on my '94 Disco. In reading what you said the codes stated, it was similar to my problem...kinda.
A few months ago I changed the clutch on my car and in trying to remove the left exaust manifold One of the wires to the oxygen sensor got pulled out of the connector, so when I reassembled the exaust system one of the wires was not connected and I knew had to get a new sensor (expensive),or splice the broken wire. Well lazy me didn't do either and the check engine lght came on after a while, but I just kept on driving because the car was running fine
So after a few months I start to feel a slight miss.
I changed cap, rotor, wires, and plugs. When I removed the plugs, all of the plugs on the side with the broken wire on the oxygen sensor were black and sooty, while the plugs in the othe bank were burning very clean..a clue !
After changing parts I tried the car and it ran fine for a few hours before that ever so slight miss was back....
so I finally spliced the broken wire...and instant fix.No more miss and I got to see first hand the communication that goes on between the sensors and the on-board computer
I would suggest that you inspect your plugs and Inspect/clean your oxygen senors.
Here in Honolulu there is an automotive radio/talk host with a large repair shop that suggests that you remove your oxygen sensors and clean them by first applying heat fom a torch then clean them and try them in your car again before buying new ones. Good Luck
 
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DiscoJag

Guest
O2 Sensor from Hell

I'm getting the oxygen sensor code - p0130? - I don't have it with me right now, but it's the one for the front driver's side upstream of the cat. I've reset it a couple of times and it has come back. My question is : how do you get the connector apart ? I found the stinking thing on a clip behind the dizzy on top of the bell housing in about the most inaccessible place possible and have tried to get it apart to no avail. I tried squeezing it and pulling and all I managed to do was to get it loose from the mounting clip. Anybody know any tricks or secrets on how to get the thing apart ? I was going to maybe try cleaning it with a torch since they are so expensive, anyone tried that ? It's got about 80K miles on it. I'm tempted to cut the wires and splice. I hate to do that but if the choice is that or my first-born child to the LR dealer ...
Jim Legge
 

Robbie

Well-known member
Apr 20, 2004
1,463
1
NOVA
i can't remember for sure, but i believe they are the push in and twist connectors.