| Author | Message | ||
     M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 763 Registered: 02-2002 |
Hey folks i need some mental help....the 94 Disco had been running great for some time (figures its about due) anyways as i was traveling on I 70 today i noticed some stuttering as i accelerated, it continued to move along at a steady pace, but if you give it some throttle it would stutter. after about 25 miles i pulled off and refueled. it had about a half a tank then. i suspected a bad plug or plug wire. i checked the wires as i refueled and noticed some arc scars on the exhaust manifold. the drivers side no. 4 wire had burnt thru. the idle was rough but would idle. as i left the sunco it ran very poor and barely pulled itself to speed. i stopped in town and shut the truck off. about an hour later i attempt to start the truck and after three attempts it fired but ran rough. i drove it about two miles to an auto zone and replaced the bad wire. the idle improved but was not back to normal. after about 6 lights i am on a back road and as i speed up i notice a lil but of stumbling so i open it up in an attempt to clear what i believe to be a fouling plug. things go south from here. it began to run so poorly that i couldnt maintain speed and pulled off. it was then the check engine light came on. i double checked the connections and no improvement. after a bit i limped the truck home. at home i disconnected the battery to reset the check engine light and after an hour re-started the truck with no improvement to the running. heres my theroy. i beleive that the grounded plug wire fouled the plug and may have allowed for an excessively rich exhaust gas condition to occurr and the result is now a burnt CO detector. but if i am wrong please point it out. any help will be met with many thanks. mike w the other opition is to trade it in on an exterra so please help me! | ||
| Richard Dekkard (Richard_dekkard) New Member Username: Richard_dekkard Post Number: 38 Registered: 04-2003 |
stuck exhaust valve? This is my answer to everything on a bad running engine now.. but seriously? is it missing? how many cylinders? pull the injectors on each cylinder while its running and see if it affects the idle.. then you will know which cylinders arent firing. Get a compression test on those, or check vacumn pressure on the line. If you get an Xterra, you cant go wheeling!!! | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 765 Registered: 02-2002 |
i will check that Richard. one thing i failed to mention there was no code on the OBD indicator. the missing was a result of a burnt plug wire. after removing it i found a fracture of the outer skin that exposed the core. so i was right about the that, so i am thinking, still, that i have toasted a plug and an O2 sensor. mike w | ||
| J E Robison Service Co (Robisonservice) Member Username: Robisonservice Post Number: 101 Registered: 10-2002 |
o2 sensors don't get toasted by misfires as a rule. I'd change the plugs and wires and go from there | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 766 Registered: 02-2002 |
thanks JE, i have noticed that the bousch plat plugs tend to foul easily and really dont self clean very well so i will start there. but to add to this issue, i have noticed a great deal of carbon around the exhaust tip. i have new cats (6k), the wires were changed last nov. and the plugs have 20 k on them. i have a K&N filter. any thoughts on this. mike w many thanks | ||
| Rob Davison (Nosivad_bor) Senior Member Username: Nosivad_bor Post Number: 303 Registered: 02-2003 |
check your fuel pressure on the rail if you can. rd | ||
| Daniel Covaciu (Danielcovaciu) Member Username: Danielcovaciu Post Number: 138 Registered: 10-2002 |
With the K&N filter makes sure that the mass airflow sensor is not fouled by oil. Just a thought. Dan | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 767 Registered: 02-2002 |
rob, i don't have a screw on fuel pressure gage, but thats a thought. Dan, the K&N has been on for over a year, so i dont think that is the error. UPDATE: changed the plug that was offended by the bad wire, no joy there. took to a mech, and he cleaned the air intake aft of the MAF. that help a great deal but on the way home it started to screw up again. so whatever it is its pissing me off! mike w | ||
| Daniel Covaciu (Danielcovaciu) Member Username: Danielcovaciu Post Number: 144 Registered: 10-2002 |
M.K. you say that the mech cleaned the air intake aft of the MAF and it helped a great deal. Just try checking the MAF for oil. Many people have had this problem due to the K&N filter. The oil from the filter biulds up in the MAF over a period of time, like maybe a year or so. I may be talking out of my ass here, but it's worth a try. It will only take you a few minutes to do this. Dan | ||
| Mark & Bev Preston (Markp) Member Username: Markp Post Number: 202 Registered: 02-2002 |
Considering that cleaning the air intake aft of the MAF helped a great deal indicates you found the area of the problem. Given that you have had the K&N in for a year, I suspect the MAF. K&N's let more air in but also more dirt. Notice K&N doesn't talk about filtration, just air flow and power gain. The oil is suppose to collect the dirt but air flow = dirt flow. Extra oil just results in more oil downstream - like the MAF and intake system. Dump the K&N and get a real air filter. | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 769 Registered: 02-2002 |
Dan, Mark and bev....I will be kickin the K&N to thr curb, the screen over the MAF was oil free but i did see the remains of a bug wing of the MAF's protective screen. i should have knwon better, i ran K&N on my race bikes but that was in a more controlled enviorment. the oil was accumlating from the crankcase vent. system. it was really knarly. UPDATE: i left the Disco at the garage all day for the wrench to drive it around and he advised that the wires and plugs were bad. he recommended that they be round filed and new ones in their place. so being that i am in chevy country the plugs were the only part to be found in the area. there is an international parts store near the baase i will hit them at lunch time. as a note i swapped the plugs out and two of the remaining plug wires pulled apart as i was removing them. my bad but they ripped in half and didnt slip out of the connector. more to come. again thanks for the input, you guys are the best. mike w | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 770 Registered: 02-2002 |
new plugs and wires has solved the problem. thanks to all mike w | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 774 Registered: 02-2002 |
i am back.....it ran great for a couple of days and then began to mis at idle, AGAIN. smooth poser thru all RPM ranges and the exhaust smell is a bit lean. i have cleaned the stepper motor but no joy there. any more thoughts. mike w | ||
| dareDVL (Daredvl) New Member Username: Daredvl Post Number: 34 Registered: 03-2003 |
Thank god it was just plugs and wires .. not valves!!  | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 775 Registered: 02-2002 |
i have not researched the valves that closely, but i dont beleive that the error is there. the fault occurrs when the engine is at operating temp. this makes me suspect a sensor. i am hoping it is something simple but MAFs and the such arent cheap. mike w ps. as a note the miss occurred after installing the new paper air filter. i cant see that the filter is the problem just funny. the power curve has dropped off enough to feel the difference. | ||
| Nathan Smith (Nathan_smith) New Member Username: Nathan_smith Post Number: 14 Registered: 05-2003 |
If you are around limited spark plugs, try splitfires. They carry them at autozone for a LR 4.0. I have had good luck with them vs. stock. Only problem is price, probably $26 for 8. | ||
| Roland Kutasi (Disco1) Member Username: Disco1 Post Number: 181 Registered: 10-2002 |
Could it be you have pick up some crap from your fuel tank and have an injector or two blocked? | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 779 Registered: 02-2002 |
thanks Nathan, i was running bosch +4 when the problem manifested the first time. splitfires are decent plugs but if i am fouling plugs left and right i would rather fry a few cheap ones until i get the problem sorted out. Roland i had the same thought but the problem is intermittent. so it tends to make me think that it is an electrical issue. a bad injector could be a source of my anexity. they have a solenoid that opens the injector valve and if the solenoid is crapping out it coulld show up in poor running. it is worth looking at just the same. thanks mike w oh another odd behavior. at 18:oo hrs i drove the beauty to london from south charleston. it missed and ran poorly the whole way. at 21:30 the trip back the truck ran flawless. geez! | ||
| todd powell (In4ma) New Member Username: In4ma Post Number: 12 Registered: 05-2003 |
um this may sound real dumb but here goes.. the other day i pulled my airbox out when changing my front shocks. when my mate put it back in he forgot to reconnect the plug for the MAF. i found the prob after about 10 mins. while it was off i gave it a spray with wd40. make sure the connection is on properly or try taking it off and spraying it out. i used wd0 but i dont know if you guys have that. even some kinda electrical cleaner would work.. just a thought... | ||
| Roland Kutasi (Disco1) Member Username: Disco1 Post Number: 188 Registered: 10-2002 |
Check the lead at both ends of the coil. If one end is slightly loose, you will experience the stuttering you describe. worth a look if you haven't already been there. | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 781 Registered: 02-2002 |
thanks guys i will try your suggestions and post the results. mike w | ||
| Scott Hayes (Scott_h) Member Username: Scott_h Post Number: 54 Registered: 02-2002 |
If I dont run permium mine will do after about 3 tanks. | ||
| Jim H. (Victor_mature) New Member Username: Victor_mature Post Number: 35 Registered: 02-2003 |
You replaced the wires and plugs but you didn't mention anything about the cap and rotor. What do they look like? If the wires were that bad, I'd replace the next two items in line: cap/rotor. Jim | ||
| M. K. Watson (Lrover94) Senior Member Username: Lrover94 Post Number: 784 Registered: 02-2002 |
Scott, i always run the costly stuff. Jim H. the cap and rotor where replaced in Feb. UPDATE:since running 1.5 tanks with a good injector cleaner thru the engine and it has improved. i am in belief that it is due for a serious injector cleaning, any thoughts |
