Hi all, I just finished up another thread for knocking code which I believe may be unrelated but just in case the background info is useful here's the link to that thread (https://landroverforums.com/forum/di...gnostic-75737/).

Here are my symptoms/observations:
1. Gas smell in oil - I have about 4k miles on 5w40 Rotella Synthetic. I didn't notice before but when I check the oil after my recent trip the next morning after a short start and trip from street into my garage, I could clearly smell the gas in the oil. I drove around for about 15 mins on freeway/local street to see if it will burn off but it was still there. This might have been stupid but I read somewhere that if you take a lighter to the dipstick, if it doesn't burn, that's probably okay...not what to make of that but it didn't burn so maybe not enough gas.
2. I mentioned in my previous thread that I have felt gas mileage dropped a a couple miles per gallon overall (and I do know about summer/winter fuel differences). It's possible that the car is just getting old.
3. Warm/hot start issues - I haven't driven it around enough after the 02 sensor replacement but it may have improved but over my recent 1k trip, it did stutter for a couple seconds when starting warm just once...if I turn key to position 2 and leave for a couple seconds, car starts with no problem.
4. Fuel pressure test - I really couldn't get the loaner kit from Autozone to fit so I jerry rigged to do some testing and it worked only once but readings came out as. Engine sitting overnight (0 psi), turn key to position 2 (31 psi), engine running (31psi), removed fuel regulator vacuum hose, jumped to 35psi). I then used a regular tire pressure gauge when engine running and it read about 31 psi as well so i think that one measurement I was able to take was accurate. Again, was only able to do this once but when I turned off the engine, I saw the pressure rapidly drop down to 10 psi, at that point the gauge stopped working so I'm not sure what happened there.
5. Brake servo leak - there is a vacuum leak on my brake servo that I need to fix (brake works fine but will be changing that soon). Will the leak affect the fuel pressure in anyway? I wouldn't think so.

At this point, my main concern is the gas smell in the oil and from reading other posts, leaky injectors could be cause but I don't want to jump to conclusions. Also, spark plugs look dry and clean where it sparks...there is slight soot on the edges but not the center where spark is generated. It's also possible that pistons are old and worn. Injectors are original and I'm okay with replacing them due to age and if there's a good chance it may help/resolve the gas in oil. Outside of that, car runs fine, no codes and per my previous thread, fuel trim levels are well within spec from my basic understanding.

I replaced the fuel pump (just the pump as recommended on this site) and fuel filter within last year.

Any recommendations on what else I can test or look at? Is this the occasion where I need to take this to a mechanic for some more testing?

Thanks
160k miles

 

Fix the booster vacuum leak and double check the FPR. Remove it and see if you can lightly blow compressed air through it (shouldn't). Check PCV as well, should be evacuating the fumes. As far as the injectors at 160k they're due for a check up. How you want to approach the injectors comes down to your choice. Techron seems to be the hot product for cleaning injectors still in the rail. Might take a couple of times to get them clean, might not work at all. YMMV.

 

Thanks, will try to find some spare time to test this further, haven't had time due work stuff....

Question: The RAVE is not clear and I've read some differing opinions around what the fuel pressure on the rail should be after sitting overnight or an hour after engine is turned off. Should the rail always keep some pressure or should that eventually reach 0 after some period of time?

 

With a check valve in the fuel pump and a fuel pressure regulator on the other end that is closed with engine off the rail should maintain full pressure indefinitely. In reality they don't due to age, wear and contamination. The injector leak test in the Rave says (using suitable injector test equipment) no more than two drips per minute per injector at 2.54 kgf/cm2 (36.13 psi). If all eight injectors leaked two drips per minute over a twelve hour period that would be 115200 drips at 36 psi, not realistic but you get the idea, the cylinders would be full of fuel.

 

Finally have some free time today. I just replaced the brake booster (good used one).

Took apart the fuel pressure regulator and it's testing okay. I blew into all ports and none leaked. Connected to my air compressor, set the regulator at 30psi, shot air into the port connecting to fuel rail and no air coming out of the return port. I increased to 33psi, same thing, no air. At 35 psi, the valve kicked in an started to release the pressure and air came out. Now not knowing exactly how it works exactly, if I recall one of the testing procedure to confirm if the regulator is working correctly is to unplug the vacuum hose while engine is running, fuel pressure on the rail should increase closer to 40psi...which I'm interpreting that to mean that when I'm testing this just by itself with no vacuum applied, should the regulator hold pressure up to about 40psi????? No sure if my logic is correct. If the regulator is okay, wondering if the check valve on the new fuel pump I put in is not working properly and allowing fuel to return to tank.???

Also, as I had taking the plenum and ram housing off to get to the fuel regulator, I decided to take the injectors out. Fuel rail is good shape and all rings on fuel injectors are in great condition. However, the injectors are dirty and the ports are even dirtier, gritty with nasty carbon deposits. I'm still debating if I should clean the injectors or buy the new Bosch Gen 3 injectors some have made it work.

But the question I have is, can I and should I attempt to clean the port on the engine with some type of solvent? I'm worried of dislodging the gunk and getting that inside the cylinder. Any advice on this would be great.

 

The fuel pressure regulator as you may or may not know is mondo expensive - I'll leave it up to you on that decision. Yours is fine actually, the most your pump is spec'd to put out by the manual is 37 lbs. Great bench method on the FPR. All you wanted to know is if it's seat/pintle had crud on it and you proved it doesn't.

I'd have the original injectors cleaned and tested or these are a an expensive option ........ lol. Bosch Injectors - Alpha Romeo, Fiat & Jaguar Fuel Injectors

Anything small that falls into the cylinders will be tossed out pretty quickly after the "bang". You may get something that doesn't want to leave and hang on to the sparklers but in most cases vaseline and a rag or cotton ball with vaseline on it will catch 90% of what you drop.

 

After thinking about my options, I think I will reinstall the fuel regulator as it does not look like that is the reason for me losing fuel pressure when engine is off. I'm going to look at the fuel pump I recently installed, I still have the original and do a swap to see.

Regarding the fuel injectors, this may end up costing me a bit more money but what the hell, I figured it's worth an try with a rebuilt Bosch Gen 3, cost reasonable enough. If it doesn't work out, I still have the originals and go get those tested and cleaned out and reinstall as they appear to be in pretty good shape on the exterior.

 

BTW....looking around for fuel injection cleaning service, anyone know of good place in Denver to take it in for service? Looking online, looks like a few offer about $18/per injector for cleaning and a "rebuild".

 

Yep on the FPR, you tested it well. What are you getting average for fuel economy - mpg?

 

Getting about 14-15mpg on Highway, 10-12 in city depending how much stop and go...probably closer to 12 because I've never truly done just city driving, always a bit mixed.