2eXceL

iTrader: (2)

So I had some time this past weekend and decided to do a full tune-up on my '96 LS400 (186K).

I replaced:
1. the Coolant Temp Sensor with one from AutoZone
2. Thermostat (O'riellys)
3. New Sparkplug wires (duralast)
4. New NGK Laser Iridium Spark Plugs
5. New Distributors and Rotors
6. Oil Change and New K&N Filter
7. Added new DEX-Cool Anti-freeze coolant to replace amount lost during tune-up.


After I finished I started up the car and let it run for about 5 minutes, mostly idling and with some acceleration on the Throttle body, I was monitoring Coolant level, temp, and everything else to make sure I didnt screw up. The car started up fine and smooth, everything looked great.
After cleaning up the Garage I decided to take it out for a road test drive, I put the AC on and drove for about a mile fairly modestly to get out to the open road. I then switched the Tranny to ECT PWR mode and punched it a few times, the car felt stronger than ever. I went on a straight a way and again punched it with PWR on to close to Redline 2-3 times going about 90 MPH, then started to slow down and brake, thats when the CHECK ENGINE Light starts Flashing.. I stop and Temp looks good, so I dont know whats wrong. The Car feels shaky so I freak out turn off AC and put Heater on, I then Drive it home about 1 mile, CEL is now fully ON and car is shaking.. I make it home and dont smell coolant or anything.
I turn it off look under the hood, dont notice anything strange, so I pull negative cable off and ECU fuse, then I start up car, now there is no CEL but the car still feels like it shakes more than normal with idle at 650 RPM...

Whats wrong? Did I screw something up? Since I had started it and let it idle for a while before driving its confusing if it is something i did but didnt notice until I drove it hard...

avalon42

iTrader: (1)

You should have pulled the code before clearing it. That would have helped us diagnose the problem accurately.

My bet is that one of your wires got chopped up and your car is stumbling because it is missing a cylinder.

2eXceL

iTrader: (2)

I routed the new wires through all the clips but they did have some slack.. still i don't think that they were rubbing anything..What could chew up the wires?

I will restart it and see if it throws the code again.

avalon42

iTrader: (1)

I've seen this problem before, it was one of the wires going to a cylinder.

2eXceL

iTrader: (2)

Drove it around the block and CEL is back ON, it flashed then stayed ON.
I am new to the LS, how do I read the CEL code.. do I short some locations on the DIAGNOSTICS terminal?

2eXceL

iTrader: (2)

While searching for how to pull CEL Codes, I think I found the old Thread you were talking about...

I removed the Sparkplug Wire Covers from each Cylinder bank, re-installed the Intake and turned on the Car... it ran smooth just like before. I took it for a drive and no CEL.
This leads me to believe that one of the wires was being pinched or caught somehow. Unlike the Thread described the Driver-side coil wire not through the window of the cover, I think my issue was the Passenger side coil wire being too long and pinched by that cover... either way I am routing the Wires to be shorter and thinking of taping them so they don't sag too much.

Thanks for the help. These aftermarket Wires are not exactly the right length

LiCelsior

iTrader: (32)

yea i had a problem like that also, the plug covers crimped one of the coil wires and made the car run like crap.

python

iTrader: (4)

i have tried to tell u guys that the oem wires are the only way to go...

Thermactor

iTrader: (1)

should have bought those oem plug wires, can you return the duralast wires?

2eXceL

iTrader: (2)

After searching through the Duralast SparkPlug Wire box I found another slightly longer Wire for Driver side Coil to Distributor.. I removed the other one and this one threads better through the Cover window. They sell this kit with extra wires???
After a quick swap, the Car now Idles smooth, BUT too Low around 200-300 RPM, CEL still on and wants to die... hmm maybe something else got tweaked during the swap.. will have to take a look tomorrow.
I do still have the Receipt and I should be able to return these cables, I will look at how much OEM cost

avalon42

iTrader: (1)

Test it out. Put your old cables back on and see if there is any noticeable difference. I personally believe that some of the aftermarket wires are absolute garbage. My friend bought those Duralast to replace factory Bosch on his MBZ, and it gave him nothing but grief. We spent an hour diagnosing his car only to find out there was a break in the wire. Twist it one very funny angle, the cylinder would finally fire. Cheap PITA. The resistance has to be also in spec, so it's going to throw and run like **** too if that's bad.

Pull the code after you swap wires (if it even comes back up).

deanshark

The Duralst wire set comes with 3 coil wires b/c the set also fits some other engines with longer or shorter coil wires. It's probibly cheaper for them to do it that way. I have the Duralst on my 93 and never had a problem. If you use the longer coil wire for the drivers side just make sure it's not touching the engine when you loop it so it fits right. The OEM wires are much better but when I did mine I was penny pinching with everything I did so I HAD to go with aftermarket.