P0305 (cyl #5 misfire)
P0300 (random misfire)
idle sets the code off but rev'ing the engine really gets the lights going.

New head gaskets
New Plugs
New Coils
140psi in cyl's
42psi fuel pressure at rails
17 inches of vacuum at brake booster port
New Passenger (Bank 2 Sensor 1) 02 Sensor cycles .300-.820 volts
Cleaned MAF with contact cleaner, unplugged MAF, cursed MAF.
Can't find any vacuum leaks

Problem comes and goes like a light switch. Instant on - Instant off. Seems to be permanently in "run like poop mode"

Driver Bank 1 Sensor 1 02 sensors reads 0.000 volts ALL THE TIME.
Swapped that sensor with another old sensor I had. Still reads 0.000 volts.

Engine misfires even when in open loop mode.

oi;erhvoirjvrj voi[;wrjgrwtogjrtwoigjrwjgwrejgilgjw!!!!!!!!!


I'm going to see if I can fix the wiring for the driver 02 sensor.. but really... would shorted 02 sensor wiring really cause all these misfires and such *terrible* performance?

When you drive it it's like the best thing you can do is lightly apply the throttle. The deeper you push the throttle the worse the misfiring gets.

 

If it reads 0.00000 volts, is there a short or ground or open wire?

 

I THINK 0 voltage should be a short. If you read applied vltage it should be open.

 

How many miles on the engine, what plugs are you using and have you checked that plug to make sure you haven't cracked the porcelin, what plug wires are you running, have you checked it for leaking?
OH, and quit cleaning a MAF when there is no indication of it acting up of you may just be adding to your expense.

 

100k miles - new autolite coppers I think. I had plat +4's in before the head gaskets.. was doing same thing.


I went out there and took the ECM plugs out and pulled the harness out thru the firewall so I could check it. I also pulled on the harness where it goes across the firewall and down to the injector rails and 02 sensors.... re-installed it... cranked it up and now it runs twice as bad.

Before I had a p0300 and p0305... now I have a p0300, p0305, p0307 and a code for "catalyst damaging condition" or something. Forgot the code number.

Also BOTH my Bank1-Sensor1 and Bank1-Sensor2 oxy sensors read 0.000 volts. Short term fuel trim is at 0 for that bank as well.

Same bank has not volts reading from oxy sensors... misfire on two cyls on the same bank along with random misfire code... Guess I'm going to have to pull the harness off and go thru it??

Do cyls 5 and 7 have something in common besides same bank? I just looked at the coil pack diagram.. 5 and 7 are on two different coil packs. Fuel injector wiring?

 

Update:

I was getting P0305 and P0300 - I swapped my #5 injector to the other side of the engine at #4 and I moved the #5 spark plug to cyl #1. Cranked the engine...

Runs a lot smoother. Still get the misfire but not near as easily and much higher in the RPM range.

Now instead of it throwing P0305 it throws P0301!! Misfire followed the plug. I'm wondering if since it followed the plug and it's a brand new spark plug if some of my other misfires are plug related? I just put all them in though. They're all new. Autolite Coppers... cheapos I know. Should I junk the new plugs and put something else in? Recommendations?

 

Champion or NGK would be my recommendation, it came with copper plugs from the factory.

 

If I was you I would change both front o2 sensor to brand new bosch sensors. Please check my thread I had a similar problem that almost made me turn my rover in for a tax return.
https://landroverforums.com/forum/di...t-47290/page2/

Also if you can pull your spark plugs out and take a picture I think ill be able to help you out.

 

UPDATE: Since I changed my #5 spark plug to #1 and saw that the misfire followed the plug and not the injector (I only had one cyl misfire other than the P0300 random misfire I was getting)... I went out today and bought 8 new Bosch Iridium's. Installed them today. PROBLEM FIXED@!@$ Yay! Runs great now. I'm so mad though at those Autolite's. They were BRAND NEW. The worked great the first day I ran them and they failed going home on the interstate. I want my money back Autolite! :P

 

Like the rule of thumb says , most misfires are the results of plugs and wires. Sounds like you got the ones that quality control missed.