2000 XJ8 4.0 no start
#1
04-16-2008, 08:08 AM
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2000 XJ8 4.0 no start
Hello to you techs, you aregreat. I used to be low level tech some years ago, so I appreciate the clarity and info presented. If I was any good, I'd still be doing it...
Here we go:
No start - 42,000 miles, new throttle position sensor, cleaned MAF with gumout, no leaks in plastic tubing from air cleaner to intake (installed correctly), replaced spark plugs with squirt of oil added too, have 40-42# at the rail schrader valve, fuel pump priming and pressure steady-(regulator and return OK), injectors clicking merrily, what next? Can I do an old time visual spark test with the coils on each plug (taking the plug out and grounding)? Way back when, I would advise dumping some fuel into the engine air intake to prime the thing. I do not see this old method advised, probably for backfire damage issues. I have cranked and cranked. No kick at all. What's next? I haven't read the codes yet (if any) because I know that the cheap consumer OBDII reader models are pretty vague (what do you expect for $100.00?) Many thanks in advance, Chuck
Here we go:
No start - 42,000 miles, new throttle position sensor, cleaned MAF with gumout, no leaks in plastic tubing from air cleaner to intake (installed correctly), replaced spark plugs with squirt of oil added too, have 40-42# at the rail schrader valve, fuel pump priming and pressure steady-(regulator and return OK), injectors clicking merrily, what next? Can I do an old time visual spark test with the coils on each plug (taking the plug out and grounding)? Way back when, I would advise dumping some fuel into the engine air intake to prime the thing. I do not see this old method advised, probably for backfire damage issues. I have cranked and cranked. No kick at all. What's next? I haven't read the codes yet (if any) because I know that the cheap consumer OBDII reader models are pretty vague (what do you expect for $100.00?) Many thanks in advance, Chuck
#3
04-16-2008, 01:17 PM
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RE: 2000 XJ8 4.0 no start
I couldn't figure out how to tighten thecompression gauge's flex hose in the well, but just bought (at lunchtime today) four of those non-foul extenders to screw together into one 7" solid extension. I have to get my kid's math studied up tonite for a test, but will reply asap. When I changed the plugs three days ago, the old ones were OK looking, nothing out of the ordinary. Is it really OK to put a few squirts of oil in? I think I under-did it. I just put a few drops in each one. Why is compression so crucial (Yes I know it's an idiotic sounding question, I mean crucial to starting.) Is the airflow measured even during start mode? OBDII next step. Thanks, Chuck
#4
04-16-2008, 06:57 PM
RE: 2000 XJ8 4.0 no start
Does it sound like a laboured crank....just on and on and on......
Compression could be an issue, but sounds more like flooded. Keep your foot flat on the floor and just hold the key in start position. Let it crank. It will take a long time.....do not let up on the cranking. You will not damage the starter. You may want to hook up a charger to it. As soon as you feel it start to fire, let foot up half way......then all the way back down on the floor.....keep repeating until it starts.
The most important part is to not let up on the key....most people let it go....then have to start all over. Just keep key cranked over.
Any chance you can post a video or sound clip of what it sounds like cranking over?
Compression could be an issue, but sounds more like flooded. Keep your foot flat on the floor and just hold the key in start position. Let it crank. It will take a long time.....do not let up on the cranking. You will not damage the starter. You may want to hook up a charger to it. As soon as you feel it start to fire, let foot up half way......then all the way back down on the floor.....keep repeating until it starts.
The most important part is to not let up on the key....most people let it go....then have to start all over. Just keep key cranked over.
Any chance you can post a video or sound clip of what it sounds like cranking over?
#5
04-24-2008, 10:43 AM
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RE: 2000 XJ8 4.0 no start
Yes, you were right, the compression was only in the 70's (???) in all cylinders. With the addition of oil, new plugs, andnew battery, (so I could finally crank for longer than 30 seconds),it fired up. Thank you so much for your help. While apart I did clean the MAF, throttle body, and (most importantly) LEARNED a whole bunch about this fabulous engine / car combo. Now for those pesky check engine codes! Regards, Chuck
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