defender starting and running issues

[Abster71]

Ok have a 2018 HD8 DPS and neighbor has 2020 HD10 limited.  We are both having the same issues start kills starts kills starts kills and then when they do stay running its very jerky for a little while then they run fine.  He took his in for 1st maintenance check and they adjusted valves fluid change ran great no issue so I did the same having valves checked and they replaced plugs only one exhaust valve was out of spec.  We are now experiencing the same issues.  Gonna check map sensor, and fuel pressure, When checking the fuel pressure do I just need to turn the key on and not start it?  I checked battery terminals also knowing the problems they've had.  Thanks for the help

[Andystoy19]

I'm not sure I can help much but here goes:

1) When you turn the key on but don't engage the starter do you hear the fuel pump cycle, if yes than you engage the starter will the engine start and run fine? Checking the fuel pump pressure it should be about 51 psi +/- 1 psi. and the pressure should not bleed off immediately.

2) When you do your initial cold start do you turn the key on and pause for a second or two or do you engage the starter all in one motion. If your fuel system has bled off pressure while sitting and you try and start it may not have enough fuel pressure to the injectors for the proper mixture and dies from a lean condition. It sounds like you have a cold start problem that could be caused by a leaking injector or fuel leak if the system holds pressure than it might be an ECM issue that isn't reading your air temperature correctly (air temp sensor)?

3) If the engine runs well after it is warm including at WOT than I would look for a slow leak in the fuel rail, hose or injectors, if those are fine and no leaks are detected it may be a defective fuel pump. SWAG on my part.

Good luck with the diagnostic on the fuel pressure system, there is a flow chart for troubleshooting the system. Were there any codes when the dealer checked the machine? 🤔  

[Abster71]

Thanks for the info I will be checking into this week.  I have now been giving it some time before engaging the start. Dealer said no codes and apparently flashed the DPS???? that's what the service writer told me didn't talk to mechanic out for lunch.  Don't think he knows much maybe there was something wrong with my power steering LOL.  I'll keep ya informed thanks again.

[Richard Rice]

I have a 2018 HD 8 Defender with several problems. It has 281 hours and 137 miles and has rarely been in dusty or dirty conditions. The problems: (1) Gas appears to be getting into the oil and diluting it. (2) When idling after some use, I can smell raw gas, (3) It backfires and pops going down a hill with foot off the accelerator. (4) It cut out, popped, and almost left me stranded while crossing a four-lane highway. 

Any suggestions?

 

[WDRHD10Colorado]

My HD10 has begun to stall after a cold start....two years old.  It runs for a time...poorly...and then stumbles and stalls.  Waiting for a few seconds before turning the key to the start position doesn't seem to eliminate the problem.  I think that I can hear the fuel pump running before turning the key to start position.  I manage to get engine running by repetitive start attempts with "light pumping" of the throttle pedal.  After the first stalls and stumbles, engine starts flawlessly throughout the day.  Do have a problem at times in PARK....no crank/no start.  If I move the shift lever to NEUTRAL...engine cranks/starts.  Bad sensor at PARK position ??  Also notice a high pitch whine when turning off the engine.  It persists for perhaps a minute and then stops.  A high-voltage capacitor somewhere ??

Any ideas greatly appreciated !  May soon buy a new fuel pump and hope that it fixes the problem.

[Steelslinger]

Check fuel filter if you haven't already.

Make sure when starting in Park that the indicator on the dash says P, sometimes even if the shifted is in Park, it doesn't click in the transmission so you either ha e step on the brake or rock the machine forward until it clicks, then start it.