RangeRovers.net Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter #1
Hi all brand new to this sight. Been pilfering loads of info since my p38 purchase and finally decided to contribute something. Not 100% this is the correct posting manner but helpful info is always helpful.

Since the day I purchased my 1998 4.6 p38 about 1 year ago it has been tremendously underpowered. The drivability was genuinely seemingly top notch. It did not stall, did not idle low or high or produce random cutouts. Just ran great! However I was convinced after the ride home w my BMW plates this rover was significantly underpowered. Well it ran so good and would accelerate sluggish to any speed I desired so after my indy mechanic gave it the all clear and even stated it felt powerful enough for a 20 year old tank beast I just kept driving as is. (Excluding odd repairs& suspension work)

play by play: will accelerate slowly to any speed but on steep climbs this can be A real struggle. If I was to far into the hill climb my speed would slowly taper off around 40-45 till the peak when I would accelerate normal again.

Rover drove fantastic besides lack of power.

Finally tired of the lack of power, my DIY diagnosis was for the mass airflow sensor. Got eBay MAF and it worked but did not cure throttle response and then 4 days later my rover basically had the flu and everything was very very bad broken down bad. Unplugged new MAF and made it home. HOWEVER now the slightest pressure applied to gas pedal would give me literally every single horse power available (never b4 felt such power w this p38, truly blew my mind) but now leaving a stop sign it looks like I'm drag racing Paul Walker's ghost. TOO much power WAY to soon. Returned this MAF and got another eBay MAF but this time from reputable UK supplier. Installed and still experienced some symptoms of bad MAF but dramatically improved drivability compared to absolutely useless. And throttle response back to sluggish.

Next I figured it was the throttle position sensor. Got that from autozone for less then $165. Got one screw out for old TPS and remaining 1 was stripped. Used Dremel to cut a slit for flathead screw bit to fit. Used penetrating fluid and couldn't believe my eyes or fingers, but it came out. Replaced old TPS w new (& 2 new bolts)and BINGO rover starts fine and now distributes power like a proper V8 pushing the pedal on steep hill climbs let me accelerate easily. No more declaration Pushing it midway gave me all the power needed to speed up the hill. And I can even stop midway and start again with all the power necessary.(this was challenging previously)

Plenty of power but now my idle is on the TOO low side and I'm noticing a slightly rough or hesitant shifting pattern. I'm confident driving 50-100 miles will get the computer stuff to adjust and correct this issue, if not I'm planning on replacing the idle air control valve.

I did do alot of searching previously but I'm not the best DIY and that's where I ended up.
Hopefully this could contribute to somebody's repairs.

Apologies if I didn't post correctly.
 

·
Registered
Joined
·
21 Posts
Discussion Starter #2
Hi all brand new to this sight. Been pilfering loads of info since my p38 purchase and finally decided to contribute something. Not 100% this is the correct posting manner but helpful info is always helpful.

Since the day I purchased my 1998 4.6 p38 about 1 year ago it has been tremendously underpowered. The drivability was genuinely seemingly top notch. It did not stall, did not idle low or high or produce random cutouts. Just ran great! However I was convinced after the ride home w my BMW plates this rover was significantly underpowered. Well it ran so good and would accelerate sluggish to any speed I desired so after my indy mechanic gave it the all clear and even stated it felt powerful enough for a 20 year old tank beast I just kept driving as is. (Excluding odd repairs& suspension work)

play by play: will accelerate slowly to any speed but on steep climbs this can be A real struggle. If I was to far into the hill climb my speed would slowly taper off around 40-45 till the peak when I would accelerate normal again.

Rover drove fantastic besides lack of power.

Finally tired of the lack of power, my DIY diagnosis was for the mass airflow sensor. Got eBay MAF and it worked but did not cure throttle response and then 4 days later my rover basically had the flu and everything was very very bad broken down bad. Unplugged new MAF and made it home. HOWEVER now the slightest pressure applied to gas pedal would give me literally every single horse power available (never b4 felt such power w this p38, truly blew my mind) but now leaving a stop sign it looks like I'm drag racing Paul Walker's ghost. TOO much power WAY to soon. Returned this MAF and got another eBay MAF but this time from reputable UK supplier. Installed and still experienced some symptoms of bad MAF but dramatically improved drivability compared to absolutely useless. And throttle response back to sluggish.

Next I figured it was the throttle position sensor. Got that from autozone for less then $165. Got one screw out for old TPS and remaining 1 was stripped. Used Dremel to cut a slit for flathead screw bit to fit. Used penetrating fluid and couldn't believe my eyes or fingers, but it came out. Replaced old TPS w new (& 2 new bolts)and BINGO rover starts fine and now distributes power like a proper V8 pushing the pedal on steep hill climbs let me accelerate easily. No more declaration Pushing it midway gave me all the power needed to speed up the hill. And I can even stop midway and start again with all the power necessary.(this was challenging previously)

Plenty of power but now my idle is on the TOO low side and I'm noticing a slightly rough or hesitant shifting pattern. I'm confident driving 50-100 miles will get the computer stuff to adjust and correct this issue, if not I'm planning on replacing the idle air control valve.

I did do alot of searching previously but I'm not the best DIY and that's where I ended up.
Hopefully this could contribute to somebody's repairs.

Apologies if I didn't post correctly.


That should be website* ?
 

·
Registered
Joined
·
21 Posts
Discussion Starter #3
Oh boy one more thing... Never got any check engine codes for any faults related to these issues whatsoever. Only thing I had within 6 months was for the purge valve and that seems to have dissapeared for months now without me doing anything. Check engine bulb in cluster is OK
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
771 Posts
The engine will sort itself out, but it takes a few miles to sort it out, if there’s anyone with a nanocom near you that could do a reset of adaptive values it should run sweet, a 5 minute job.
 

·
Registered
Joined
·
21 Posts
Discussion Starter #5
The engine will sort itself out, but it takes a few miles to sort it out, if there’s anyone with a nanocom near you that could do a reset of adaptive values it should run sweet, a 5 minute job.
Figured I would keep up with my results considering there's so many potentially varying issues when it comes to these sensors. Good idea for computer, just don't have any rover friends in upstate ny.

After changing the previously mentioned TPS and MAF i had very positive results but not a finished product. With my idle at a constant way too low I continued driving hoping for a computer correction but the idle really just seemed to become worse and eventually it just kept stalling. Now it will fire up but refuse to keep idle. Unplugging the MAF allowed me to find an idle by using the pedal to increase rpm but it just wasn't right plus my MAF is unplugged. I cleaned IACV and it did start and idle high with MAF plugged in. Shutoff & Tried again now it is back to instant stall. Everything is original or very old on my P38 so I'm just in routine with replacing anything I can get my hands on. Bought new IACV $18 with tax at autozone. They offer warranty and guarantee so what's the risk. installed new IACV and everything plugged in it starts right up and seemed confused how to idle and began idling high about 19 or 2. However while in gear it did idle correctly, compared to previous stalling in gear. I have been switching my new UK brand and original sage MAF a little during this process for a control kindve thing. Left rover as is overnight and in the morning it was idling decent, not high & maybe a little low. This was with orginal sage MAF Almost felt perfect but I am not convinced 100% yet.Obviously will try my UK MAF next.
I'll finish hopefully with a conclusion after a few days of testing.


I keep thinking my oil separator may be very dirty. The driver side rocker cover breather hose or whatever short length of L shaped hose I believe it's part # ERR7272 is just about as fragile as wet toilet paper.

?
 
1 - 5 of 5 Posts
Top