99D1 4.0L. I have tried just about everything. It all started about a month ago. I got codes for my two downstream O2's. They have been changed. My engine is acting like it is chokeing out. If I'm at a stop and I push my foot down on the gas pedal it chokes out from idle until around 2000 RPM's. Then it gradually starts to increase motion until around 3000 RPM's and smoothes out. This engine has no guts. It is so weak. Once I'm over 25-30 MPH and I stomp on the gas pedal it will hit passing gear but dogs out and hesitates. I have changed the downstream O2's, MAF and ETC sensor. What am I missing here?

 

Maybe a TPS on the fritz?

 

Clogged cats.

 

im with Brian, tap them suckerz and see it crap is rattling around in there

 

How many miles on the truck, when was it last changed along with plug wires, when was the fuel filter changed?
If you go drive it hard, will it throw new codes, if so what are the fault code numbers?

 

I thought the Cats were bad too. They are filled with black soot. But my engine still runs very rich. If I put new Cats on again it will just tear them up also. Cats are just the effect, something else is the cause. My TPS has been tested thoroughly. There are no bad spots in this TPS. The signal is good. I'm still hooked on possibly being fuel pressure regulator. I took the one off my old 97D1 and put it on this engine. Not sure if it was the exact smae. I know I had to re-due the fuel hose to the pressure regulator because it was a different mate. Something is causing flooding. My system is clogged with black soot (carbon). My plugs are Bosch P2 with Denso wires. They were changed in January. I just cleaned the plugs last week because the scanner showed a fouled cylinder. Ran good for a couple days. I only had two codes on this machine. They were downstream O2's. They have been changed. I never changed the fuel filter, but how would a fuel filter cause flooding anyways? No codes at present and no check engine light.

 

I know it's apples and oranges.......but my 2000 Nissan Maxima had VERY similar symptoms.......turns out it was the coils.

 

Any chance the upstream o2's are shot? They could have a hand in all the stuff your describing right?

 

Well, my theory is that you are a moron.

Lets see, from the post three threads down:

You didn't baseline anything to start out with. You did not replace your O2 sensors, you soldered in some random untested used things from a different year. You then reported that your sensors were giving you voltages with the engine off. Yeesh. Do you have any idea how the actually work?

I observe for the most part, and contribute when I can. There are a lot of smart guys here who are usually willing to go WAY out of their way to help out those who know less.

You sir, are not one of those guys.

You have completely ignored all the good advice that has been given to you. You are monopolizing this board with your braindead projects that will never come to fruition and your braindead comments and need to stop it immediately. Be useful. READ what people write in your threads. Don't post if you don't know. That write up for the steering box rebuild was lame but gets a C+ for effort, but I suspect it is a thinly edited copypasta from some other place.

There are many on here I suspect who also feel the same, which is why nobody responds to your posts anymore. I'm just nice enough to tell you why.

Good luck, I hope you get your truck squared away because it is obvious that you love the thing. Just try to be a little less toolish while you hang out here.

Just a friendly suggestion.

 

Geek_IM for your information the O2 signal voltage test was with voltage supplied/ engine off and voltage supplied/engine running. You should read a little closer. I accept everyones advice if I have not already been down that road. Simple story. You did not add anything other than ignorance to this thread. My truck still has a malfunction. Unless you have a solution that I have not tried. Find somewhere else to hang out and play typeing games. Again, what have you contributed to the Land Rover Community?