Power lose mid throttle P1316
Thread Starter
|
Mudding
Joined: May 2009
Posts: 121
Likes: 0
From: Arlington TN
I'm doing the filter next. Only thing left to get the fuel pressure up is changing the pressure regulator. It's next. its a nagging problem at this point. Truck runs great, just has a misfire at idle and while maintaining speed when the fuel pressure dips to around 26
Three Wheeling
Joined: Nov 2018
Posts: 70
Likes: 0
That's exactly what mine does. Do you have a scanner to monitor the short and long fuel trims? Wonder if yours is running super rich like mine at idle. I definitely have the same symptoms as you.
Camel Trophy
Joined: Jan 2010
Posts: 4,245
Likes: 402
From: Traverse City MI
Rich at idle in regards to the FPR would mean it’s not allowing fuel to return back to tank, FPR would be closed forcing more fuel pressure to injectors. Vacuum pulls the diaphragm off it’s seat. At open throttle less vacuum hence more fuel to injectors.... diaphragm on it’s seat. It’s very rare the FPR fails, probably one of the best there is. Yes they’re 22 years old but it’s just so uncommon. They’re expensive too. Being pre AEL your gas caps should be vented, are they? Make sure your fuel tanks aren’t collapsing as that would make the fuel pump pressure weak. Check vacuum lines to FPR. Check engine vacuum. I hate Rover open loop fuel rails.....
Three Wheeling
Joined: Nov 2018
Posts: 70
Likes: 0
Rich at idle in regards to the FPR would mean it’s not allowing fuel to return back to tank, FPR would be closed forcing more fuel pressure to injectors. Vacuum pulls the diaphragm off it’s seat. At open throttle less vacuum hence more fuel to injectors.... diaphragm on it’s seat. It’s very rare the FPR fails, probably one of the best there is. Yes they’re 22 years old but it’s just so uncommon. They’re expensive too. Being pre AEL your gas caps should be vented, are they? Make sure your fuel tanks aren’t collapsing as that would make the fuel pump pressure weak. Check vacuum lines to FPR. Check engine vacuum. I hate Rover open loop fuel rails.....
The gas tank was recently replaced by LR per the recall, along with the vent hose, and the gas cap grommet which serves duty as a gasket. The gas cap is a generic unit from AutoZone (from PO). I was not aware these had vented gas caps.. where do you get a replacement for that? None of these problems were occuring prior to the fuel tank replacement. I don't have my vacuum tester nor a fuel pressure tester because I'm currently on the road, but will confirm once I get home. Assuming the truck makes it. In regards to vacuum, I tried a few things to diagnose based on the fuel trim, one of which was creating a vacuum leak by pulling the PCV hose to see if the engine would lean out. Once pulled (while running) bank 2 short term immediately went from -15 to 0, however bank 1 remained at -25 (max fuel subtraction). I have a feeling this should communicate something but am still learning the diagnosis portion of engines.
Camel Trophy
Joined: Jan 2010
Posts: 4,245
Likes: 402
From: Traverse City MI
Vented cap on all pre AEL, Sealed on AEL. My early 97 pre AEL required a vented. The dork who owned it previously had a non-vented and the tank nearly imploded and the motor ran same as you guys, like crap mid throttle. Rovers are also a picky bastard about O2 sensors. Buy OE if possible. 96s are a funny breed, first GEMS iteration, I wouldn’t doubt you both could use a reflash of the ECU. First GEMS in a Disco, the actual first was a 95.5 Rangie and a whole different brotha.
Last edited by ihscouts; Nov 25, 2018 at 02:41 PM.
Three Wheeling
Joined: Nov 2018
Posts: 70
Likes: 0
Vented cap on all pre AEL, Sealed on AEL. My early 97 pre AEL required a vented. The dork who owned it previously had a non-vented and the tank nearly imploded and the motor ran same as you guys, like crap mid throttle. Rovers are also a picky bastard about O2 sensors. Buy OE if possible. 96s are a funny breed, first GEMS iteration, I wouldn’t doubt you both could use a reflash of the ECU. First GEMS in a Disco, the actual first was a 95.5 Rangie and a whole different brotha.
Rover's North Gas Cap Example
It does not specify if it is vented or not. Any ideas?
Thread Starter
|
Mudding
Joined: May 2009
Posts: 121
Likes: 0
From: Arlington TN
ok. I replaced the filter today. Same results. Stumbling off idle, rough idle, loses power when cruiseing but instantly runs perfect if I give it more gas. Also noticed a few pops through the intake when leaving a stop sign. That just makes me think it's leaning out at little to no throttle. Im beginning to think maybe it's not a fuel pressure issue but something else. o2 sensors?