So i've been tackling some weird fuel issues and ultimately replaced the fuel pump. To summarize I was having lean codes and backfiring when starting up. I would also lose power on the highway if I went over 2500 rpms for too long with it having very little power to begin with.

Replacing the fuel pump made it better but not fixed by a long shot. Now I have less sluggish feeling but I still have some other related issues. On cold starts it still backfires a little bit when giving it gas when it is warm enough out. If it is a cold morning and I even touch the gas slightly, or even put it into drive before it has time to warm up a little bit, it stalls. When warmed up, I still have that second or 2 of hesitation when using gas. It will drop rpms no matter how much gas I give it for a second then get a little power and start to move. Trans kickdown does absolutely nothing, it'll spike to 3500 rpms and get no noticeable power or acceleration over letting it stay in a higher gear.

I unplugged my maf to see if that would help but hasn't changed much in the few days of running it disconnected.

This morning I noticed my ultra gauge had an error on the coolant temp gauge. Is there only 1 ect in this truck and could that failing be causing the running problems? Would the maf or ect or both be causing the truck to not accelerate? There aren't any other useful codes right now, just the 2 maf codes because it is unplugged and 0733 which from my reading is usually related to a maf about to go despite its listed as a trans code. There is also the typical 1884 or whatever code that pops up whenever any other code exists it seems.

 

The 1884 is a tranny multiple screw up possible code. You'll need MAF connected. Engine computer and tranny computer always talking on the data bus. Throttle angle, computed torque, who knows what else. Not like the old days with big engines, pedal to metal and light the tires. Now we put pedal to open the throttle butterfly, and that MAF has to tell computer that more air mass is passing this point in the system, better add some width to the injector pulses so we can maintain 14.7 air fuel ratio; keep checking that throttle position to see angle of the butterfly valve brought on by the increased pressure of the right foot in a futile attempt to keep pace with the hot babes with the 5.0 liter Mustang convertible in bikinis on the way to the beach. Well, you get the picture, all you mechanically control is the butterfly valve, Rover does not trust us with fuel directly. In later models with electronic throttles, it is pedal to the electrons, make them scamper to the ECU and get this 5000 pound possum smasher up to the born to be mild acceleration it is capabale of .

There is only one coolant temp sensor that is used by the ECU to impact fuel issues, it is between AC compressor and alternator on top of engine. Reseat connector. On the ultra gauge see if you can get a reading for coolant temp, and check this as truk warms up. Should start at ambient and move to 180 - 205 F. If it is -40F, might be unplugged. Normally this will make truck idle high and run rich.

Also see if you can get UG to show you throttle position %. The TPS base is like 9.8% (not zero), and it should move smoothly thru the range as you opeate accelerator. TPS sensor could be bad, throttle body could need cleaning, PCV system could be blocked up. Linkage could be sticking or binding.

Is engine responsive in park vs what you mention for in gear operation? Or have you got some other tranny problem?

 

What he said ^ EXCEPT your throttle base can be. 0. This is why Rogers have adaptive values, my last two Rovers bass was at 12 but since it can varry, land rover builds the engine throws a tps on and tells the. Imputed what ever your reading currently it base or 0. This is why if you change TPS it can really screw with your truck without reprogramming.

Also you said with the maf unplugged no change? I'd be looking at maf.. Did you have a code before you unplugged it?

Look at my recent post, you can get a brand new Maf sensor for as little as 40$

 

new Maf sensor

 

I dunno - it is in the 9% range on GEMS D1s. The pre-GEMS system had a mechanical base idle position, but that went away with the adaptive value computers of later models. The Bosch system on a D2 is supposed to throw a code P0122 if TPS is below 3.9%. So I think electrical "zero" might not be desired. See attached from Bosch manual. But let us assume that it has a number, and that we can see it, the important thing is that it changes, and smoothly; not like the static on a dirty volume control on a car radio or grand dad's Vox Super Beatle amp.

Agree with clean when cold MAF sensor or replace.

 

The cold gas issues happen in park as well. This morning in park (was 46 deg) right after start I just barely touched the gas enough to rest my foot on it and the RPMs dropped and the truck stalled. There may be a 0122 code in there as well but right after I disconnected the maf a few codes popped up so I contributed them to the disconnection. I'll go out at lunch and get the full code list.

 

Went out and checked on my break instead, code list p0102, p0112, p0733, p01884, no pending. I brushed off the first 2 since, as I said, weren't there until I disconnected my maf then suddenly they were. TB issues make sense given the throttle response (or lack of) I get.

Ha beat you to it mike, its the OEM maf that's been in there since it was born in solihull. I am probably going to buy a VW maf and change out the element since supposedly its the same and less than half the price if that's an issue.

 

How about start by giving us the exact fault code numbers so we have a better idea what is going on. Also, who's MAF did you install, does it have the same part number stamped on the barrel as your old one had?

 

Sorry, just missed your last post, those codes add up to a bad/wrong MAF, so still need to know information of your new MAF?
Leave the t/body along for know.

 

With the MAF disconnected shouldn't it run better though? It doesn't seem to have any major difference between connected or not.