Since I replaced the MAF the week before last, I've had this throttle lag & a reoccurring trouble code 1179. Thought it might have been the TPS, but replaced it with a new one yesterday and it's still there. The lag only happens when I step on the gas harder than usual like pulling into traffic from a stop sign (the truck sits for a second or so, and then takes off), but the TPS reading on the Ultragauge jumps from 11.8 to 39.4 before it comes off idle and moves). If I ease on the pedal it's okay with no lag at all. The trouble code pops up on the Ultragauge a couple of times a day since I replaced the MAF, so I can't help but to think they are connected somehow. I know there was a thread on here earlier this week about the rubber gasket between the MAF and the air cleaner, but there wasn't one there with the old MAF, and not one in the box with the new one. I asked, but the supplier said there was no need for one. What am I missing?

 

Air filter, fuel filter, 02's, fuel pressure and MAF. Well you just replaced the MAF so it has to be one of the four left. Your not getting enough fuel according the code.

If your fuel pump is more than a few years old check the sock. If you don't know when the last time the fuel filter was replaced, replace it. Same for the air filter.

02's are generally one of the most overlooked pieces of kit on any vehicle. The older they are the slower they get and 100k is about the max before they're useless. Replace the uppermost 02's first.

You want mid 30's or better on fuel pressure, anything less is a crap shoot and generally causes hair pulling. AEL's are about the touchiest trucks on the planet, right up there with the P38.

Git er done.

 

Could it be the fuel pressure regulator? Or vacum hose to it?

 

Not likely. The code refers to lack of fuel. If the FPR was chunked it would over fuel at idle since the diaphragm wouldn't move pintle off it's seat.

 

There is an O-ring between the MAF and the air filter box.

I recently changed my air (and oil) filter and the person helping me unlatched the top of the air filter box from the MAF in order to get the top of the box out of the way (I just lift it up and flex the intake hose a bit). He didn't realize the O-ring was there and indeed, without either of us noticing, the O-ring fell to the ground.

I start the truck to check that all the plugs are back in correctly and are not leaking and low and behold it is very hard to start and takes several more cranks than normal (usually it starts right up).

We move the truck a bit to clean some minor bits of spilled oil and find the O-ring on the floor. At first we didn't know where it came from and even suggested it have been there prior. The the light bulb went on in our heads and realized there is an O-ring next to the MAF. Re-installed it and all was back to normal.

Here is a parts diagram from Rovers North....

Discovery I Fuel Air Intake - Rovers North - Classic Land Rover Parts

 

Okay, I really hate when a British "parts expert" from an purposely unidentified British box store doesn't know their product! I asked the rep at purposely unidentified British box store (3) times (on 3 separate occasions) if there was an o-ring between the MAF & air box and was told no. Made one call to Lucky8 (shameless advertising kudos); they knew exactly what I was talking about, and have the missing o-ring on it's way. As for the rest of the suggestions, fuel pressure 38psi, new air filter & intake air temp sensor when the MAF was installed, Magnacore 8mm plug wires, fuel filter, and fuel temp sensor are about 3 months old. As far as I know, the O2 sensors are original with 167,000 miles on the truck, but the Ultragauge shows O2 sensor bank 1 as .2 - 1.0 depending on speed & load and the reading is constantly changing, and O2 sensor bank 2 steady as a rock. Guess I will see if the o-ring fixes the issue when it comes from Lucky8.

 

Just trying to get my head around the oring because I have problems and have never seen one that big. Is it where the spring clamps hold the hose together between the MAF and the squarish air box?

 

Charlie...yes, exactly. He un-clipped the top of the air box from the MAF and it fell out. The O-ring is approximately the same size as the intake hose which use a 70-90mm clamp. So figure on somewhere in the neighborhood of 3" in diameter.

 

I have taken like half dozen off in jy , oring always missing

 

Well, if this isn't it, I'm at a loss...