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Hey all. I just got this 03 S type 3.0 5 speed manual up and running and it drove around the block but then it started sputtering and low idle and dying out basically. Sounds horrible so I kill it quickly when this happens. If I’m sitting in the driveway and hold the gas at 3k rpm she’s fine and no issues. The highest my scanner shows the fuel pressure at is about 375kpa maybe and it’s normally about 300kpa when running fine. When it starts to bog and die it starts dropping the kpa to 100 or less. The donor engine fuel rail had a cracked injector so I swapped rails from the bad engine that I never heard run, so I can’t say what could be wrong with it or the FPR sensor at the back. The vacuum hose portion is broken off the other sensor and rail I have so I can’t swap that. I do have an extra fuel pump that was working fine I could swap in but I don’t want to throw parts at it yet, curious on if anyone has had this issue or has some insight.
Current car and fuel pump sat for the last year as well.
Does anyone know where pin 73 on EN1 is located? My FPR sensor tests ok. The signal wire pin has 5v switched on and the resistance on pin 2 to ground is in spec so that leaves pin 3 to check and it says check it to pin73 on EN1. If anyone can help with that it would be much appreciated. Thank you.
It’s so odd, car will lose pressure and die within 30 seconds. Last night I held it at 3k rpm for a very long time. Maybe ten minutes plus. Fuel pressure was around 300kpa the whole time. Almost normal spec. Now the car runs about 250kpa and will drive. Albeit slowly and not past 4k rpm. But there has been an improvement. If you clear the code the fuel pressure rises to about 350kpa but once the light comes back on it goes down to either 0 and shuts off or now mostly staying around 250 and running. I do not believe this to be a fuel filter or line clog problem as the fuel pressure shoots up to spec when you clear the code. Any help or suggestions is appreciated.
I wouldn't keep doing that unless you make sure as you do it that it's running CL (closed loop) and that the fuel trims are OK.
You also describe the PCM (aka ECM) taking some sort of evasive action so it's unhappy and trying to cope - it will try to save your engine but will sacrifice the cats if needs be. They're costly!!
If you were parked I'd also check the trans temp just in case it's getting rather hot.
I wouldn't keep doing that unless you make sure as you do it that it's running CL (closed loop) and that the fuel trims are OK.
You also describe the PCM (aka ECM) taking some sort of evasive action so it's unhappy and trying to cope - it will try to save your engine but will sacrifice the cats if needs be. They're costly!!
If you were parked I'd also check the trans temp just in case it's getting rather hot.
thanks for the reply, once warmed up it was closed loop with acceptable trims. Just not enough fuel pressure in general. I’m not sure what evasive ecu action you’re mentioning - just the declining fuel pressure issue. I will check pin 73 on the ecu to see if it’s getting proper signal today, had to wait on the 5 point bit for that as all of my security torx are 6 point.
Also as mentioned this is a manual so no worries on the trans temp.
Ok well I was able to check continuity from the harness pin 3 to ecu pin 73 and it was fine, although harness pin 3 to ground had only 5k ohms resistance and was supposed to be at least 10k ohms. So I rewired that wire and everything is still the same sadly. The resistance is exactly the same at 5k ohms and the problem persists. I don’t understand what could be causing this.
Is there a way I can safely power the fuel pump at 100% to test it and get a higher pressure in the lines?
Is there a way I can safely power the fuel pump at 100% to test it and get a higher pressure in the lines?
I do not recommend this. When my ‘02’s fuel pump gave up the ghost a couple of years ago, I considered doing the same thing to confirm the pump was bad before replacing it.
I had second thoughts as I’m pretty sure the RECM has some sort of current limit protection for the pump. If the pump itself has some sort of internal fault, it doesn’t seem safe to apply full power while it is submerged in the fuel tank.
Ok well I was able to check continuity from the harness pin 3 to ecu pin 73 and it was fine, although harness pin 3 to ground had only 5k ohms resistance and was supposed to be at least 10k ohms. So I rewired that wire and everything is still the same sadly. The resistance is exactly the same at 5k ohms and the problem persists. I don’t understand what could be causing this.
Can you please elaborate where you are getting these test procedures? Are these the pinpoint tests from the Field Service Manual? I’m not sure how you’re supposed to see 10k ohms of resistance in a wire run, so there must be some component in the circuit responsible for that.
Can you please elaborate where you are getting these test procedures? Are these the pinpoint tests from the Field Service Manual? I’m not sure how you’re supposed to see 10k ohms of resistance in a wire run, so there must be some component in the circuit responsible for that.
thanks for the info on the fuel pump. And yes these are from the FSM workshop manual. It shows on step B3. I mean I have a parts car I could switch the fuel pump over but I think this is more of a wiring issue. Or maybe ecu could be damaged. I have an auto ecu maybe I could try it to see if the fuel pressure gets corrected although I’m guessing it may throw auto trans related codes.
Last edited by Krsone5791; Oct 20, 2024 at 09:04 PM.
Had a little more time to dig deeper. I see you've been chasing wires, but I'd suggest holding off on that for right now. Look at some basics before going down any particular rabbit trail.
For 2003, see page 25 of the PDF for what Jaguar says for P0191. Note the first thing they mention under monitoring conditions, or basic prerequisites:
Fuel level greater than 25%.
This is important, because the tank has an oddball saddle shape. There's only one electric pump, installed on the right side. There's a set of crossover pipes and a venturi on the left side. Any time the electric pump is running, the venturi is supposed to draw fuel from the left side and transfer it to the right. Once you get down below approximately 1/3 of a tank, the left side should be empty and all fuel is on the right. If the venturi action is not working, your fuel gauge could still show plenty of fuel, but it's all on the left and unusable. The electric pump would be starving. So for starters, make sure you've got a full tank of fuel to eliminate this possibility.
Under possible causes, check out the first item:
Fuel filter / system restriction
You had previously mentioned you didn't think the filter was responsible, but I'd change it anyway. It that's not it, I won't feel the least bit bad because changing the filter is routine maintenance. For giggles, use a pipe cutter and open the old filter for inspection. You might be surprised what you'd find. For example, here's what I found when I cut open the old filter on my '02 V6, maybe three years old:
The next likely possible causes:
Fuel system leak
Incorrect fuel pump output
A leak could be on a line inside the tank, with the pump output getting dumped back into the tank. You would not necessarily have an external leak.
Incorrect fuel pump output? This could be a marginal or erratic pump. Personally, I'd hold off on replacing the pump just because it's a lot of work. I'd be more inclined to replace the pressure sensor on the injector rail.
Had a little more time to dig deeper. I see you've been chasing wires, but I'd suggest holding off on that for right now. Look at some basics before going down any particular rabbit trail.
For 2003, see page 25 of the PDF for what Jaguar says for P0191. Note the first thing they mention under monitoring conditions, or basic prerequisites:
Fuel level greater than 25%.
This is important, because the tank has an oddball saddle shape. There's only one electric pump, installed on the right side. There's a set of crossover pipes and a venturi on the left side. Any time the electric pump is running, the venturi is supposed to draw fuel from the left side and transfer it to the right. Once you get down below approximately 1/3 of a tank, the left side should be empty and all fuel is on the right. If the venturi action is not working, your fuel gauge could still show plenty of fuel, but it's all on the left and unusable. The electric pump would be starving. So for starters, make sure you've got a full tank of fuel to eliminate this possibility.
Under possible causes, check out the first item:
Fuel filter / system restriction
You had previously mentioned you didn't think the filter was responsible, but I'd change it anyway. It that's not it, I won't feel the least bit bad because changing the filter is routine maintenance. For giggles, use a pipe cutter and open the old filter for inspection. You might be surprised what you'd find. For example, here's what I found when I cut open the old filter on my '02 V6, maybe three years old:
The next likely possible causes:
Fuel system leak
Incorrect fuel pump output
A leak could be on a line inside the tank, with the pump output getting dumped back into the tank. You would not necessarily have an external leak.
Incorrect fuel pump output? This could be a marginal or erratic pump. Personally, I'd hold off on replacing the pump just because it's a lot of work. I'd be more inclined to replace the pressure sensor on the injector rail.
Those were both on SC models, but I think the general principles are the same for the V6.
Hey I appreciate the lengthy response and thank you for the reply. I will check out that link as well. Also the sensor has been changed with another one and no change. Also both sensors tested good. Even a new sensor changed nothing. Believe me I wish it was just a sensor but it seems to be more than that. Fuel filter has been changed sorry for not updating that if I haven’t. Fuel level is 3/4. Also if you give it gas when first started it will stay around 270kpa but will sputter out if you let go and pressure drops to below 150kpa. When you turn the key to the run position the pressure does not get high maybe 150kpa. I believe it should be at 47psi or 300+ kpa and my scanner reads out in kpa. It’s making me think it could be the pump since it puts out low pressure but idk. I have pulled the donor car’s fuel pump and may just go ahead and change it. Only took a few minutes to remove donor pump under seat and access cover ( I heard there is no access cover but I have both) Well it’s still attached by one hose as I was just siphoning all the gas out for the yard machines but I will need to look up how that hose comes off. It wasn’t the quick connect line.
my friend suggested putting the auto ecu back in to see if the ohms go above 10k between pin 3 and ground as well.
Last edited by Krsone5791; Oct 22, 2024 at 09:56 PM.
Update - was the fuel pump. Car running good with no warning lights. Brakes are not as good as they should be thought and for some reason my autel scanner isn’t giving me the ABS bleed option. Only read codes and live data for abs system. Is this a common issue or anything I’m missing? Have used my scanner for many ABS bleeds before.
P0191 Issue
