'05 STR Won't Start
#21
Hmm, interesting. What did it take to diagnose that? Did the cams not rotate at all? Or had the chain jumped but the cams were still rotating?
What was the cranking speed like when you turned the key to start? Was the RPM normal as before? Or was it faster, slower, or erratic?
What was the cranking speed like when you turned the key to start? Was the RPM normal as before? Or was it faster, slower, or erratic?
Had it towed to British Automotive locally and we lucked out, no valve/piston contact, just jumped timing on one cam. New metal tensioners and it runs like a top.
Last edited by DigitalDisaster; 05-16-2017 at 11:18 AM.
#22
Join Date: Nov 2013
Location: Inverell, NSW, Australia
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Worried that we are getting confused here. Broken t/c tensioner and skipped cam on an early 4.0L has little or no bearing on the later 4.2L, for which this built-in frailty was never an issue.
Karl's good advice to focus on one thing at a time is sound and since your fuel rail pressure is sub spec, then disappears once not cranking, this is the logical place to start. However, I am further worried that brand new plugs are "wet" and/or "fouled" . . . perhaps implying not a lack of fuel but lack of ignition and/or correct ignition timing.
What worries me most is that this was a slowly deteriorating fault spanning several weeks of worsening fuel consumption that was resolved, not by successful diagnosis and repair, but by engine eventually refusing to start. Two relevant questions . . . where in this process, and why, did you swap in the XF fuel tank, pump and delivery system? . . . and if so, how long was the car running at full optimum performance with all the XF stuff before fault/s first emerged?
Best wishes,
Ken
Karl's good advice to focus on one thing at a time is sound and since your fuel rail pressure is sub spec, then disappears once not cranking, this is the logical place to start. However, I am further worried that brand new plugs are "wet" and/or "fouled" . . . perhaps implying not a lack of fuel but lack of ignition and/or correct ignition timing.
What worries me most is that this was a slowly deteriorating fault spanning several weeks of worsening fuel consumption that was resolved, not by successful diagnosis and repair, but by engine eventually refusing to start. Two relevant questions . . . where in this process, and why, did you swap in the XF fuel tank, pump and delivery system? . . . and if so, how long was the car running at full optimum performance with all the XF stuff before fault/s first emerged?
Best wishes,
Ken
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kr98664 (06-10-2023)
#23
Ken, I want to make sure I understand you correctly. Based on this comment in your initial post, there seems to be some ignition, right? Might be weak, might be at the wrong time, but there seems to be something happening in the ignition department?
I just want to be sure the low fuel pressure isn't a red herring.
I just want to be sure the low fuel pressure isn't a red herring.
Those OEM fuel pressure sensors are starting to be hard to find. Might be wise to get one, if you have a car which it fits, while they are still somewhat available. The local Jag dealer couldn't sell me one, so I ordered direct from Ford.
#24
Worried that we are getting confused here. Broken t/c tensioner and skipped cam on an early 4.0L has little or no bearing on the later 4.2L, for which this built-in frailty was never an issue.
Karl's good advice to focus on one thing at a time is sound and since your fuel rail pressure is sub spec, then disappears once not cranking, this is the logical place to start. However, I am further worried that brand new plugs are "wet" and/or "fouled" . . . perhaps implying not a lack of fuel but lack of ignition and/or correct ignition timing.
What worries me most is that this was a slowly deteriorating fault spanning several weeks of worsening fuel consumption that was resolved, not by successful diagnosis and repair, but by engine eventually refusing to start. Two relevant questions . . . where in this process, and why, did you swap in the XF fuel tank, pump and delivery system? . . . and if so, how long was the car running at full optimum performance with all the XF stuff before fault/s first emerged?
Best wishes,
Ken
Karl's good advice to focus on one thing at a time is sound and since your fuel rail pressure is sub spec, then disappears once not cranking, this is the logical place to start. However, I am further worried that brand new plugs are "wet" and/or "fouled" . . . perhaps implying not a lack of fuel but lack of ignition and/or correct ignition timing.
What worries me most is that this was a slowly deteriorating fault spanning several weeks of worsening fuel consumption that was resolved, not by successful diagnosis and repair, but by engine eventually refusing to start. Two relevant questions . . . where in this process, and why, did you swap in the XF fuel tank, pump and delivery system? . . . and if so, how long was the car running at full optimum performance with all the XF stuff before fault/s first emerged?
Best wishes,
Ken
I started getting a stumble and RP lights after that. Found out my intercooler pump was dead, and the wiring harness body plug up there had shorted out and was loosing injectors randomly. Fixed that, and replaced the DCCV valve while I was at it. Ran well for a good while, then started my current adventure.
#26
I'm running an Xtool Bluetooth module on my '02. I went with this because it's one of the few advertised to work with an iPhone:
It works well with the free app. No dealer-level stuff, but it does handle all OBD II functions and can graph live data.
If you have an Android phone, you have a lot more options.
This is one of those times a scanner, even a basic one, is worth its weight in gold. It will immediately tell you if the fuel pressure sensor is putting out an inaccurate signal, so you'd know how best to proceed.
#27
#28
Does the PATS light go out OK, or does it flash rapidly then a code?
Yes it has CMP sensors. Details w/ pics in workshop manual - free download.
Doubt it's CMP. CKP, yes could be. Ideally you'd watch its signal e.g. with a scope as you crank.
I was expecting more like 55psi but I think it ought to try to start with less. The fuel pressure should NOT drop after key off, at least only very very slowly.
Yes it has CMP sensors. Details w/ pics in workshop manual - free download.
Doubt it's CMP. CKP, yes could be. Ideally you'd watch its signal e.g. with a scope as you crank.
I was expecting more like 55psi but I think it ought to try to start with less. The fuel pressure should NOT drop after key off, at least only very very slowly.
#29
The car turned over and would even sort of start if the pedal was held to the floor but it was extremely rough - barely running (I would have never attempted it if I had known it was a cam chain issue).
Had it towed to British Automotive locally and we lucked out, no valve/piston contact, just jumped timing on one cam. New metal tensioners and it runs like a top.
Had it towed to British Automotive locally and we lucked out, no valve/piston contact, just jumped timing on one cam. New metal tensioners and it runs like a top.
#30
Just beware of making the symptoms fit a pattern failure, especially when that failure is very rare for this engine. Need some personal examples of troubleshooting the hard way? How much time do you have?
I hate to bring it up again, but you're really flying blind without a scanner. They are super cheap these days, and indispensable for observing inputs such as fuel pressure and CKP output.
#32
#33
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KenAdamson (05-18-2017)
#34
I'm taking the day off from fretting about my car. I have in hand a NEW, OEM CKP sensor, and a NEW OEM, FRP Sensor. FRP will go on tomorrow evening, and I'll recheck the pressure output.
I do have an OBD to USB adapter - if that's what you're talking about by "scanner". It tells me a different story about fuel pressure than the manual gauge, which is definitely suspicious. I don't know how to read CKP output (there isn't a PID for that specifically) - unless that's where it gets its RPM information from, which I said before is something like 150rpm while cranking.
I can do a compression test. In fact, I had planned to, but my compression gauge won't go down into the plug holes. I need to get an extension for it.
I do have an OBD to USB adapter - if that's what you're talking about by "scanner". It tells me a different story about fuel pressure than the manual gauge, which is definitely suspicious. I don't know how to read CKP output (there isn't a PID for that specifically) - unless that's where it gets its RPM information from, which I said before is something like 150rpm while cranking.
I can do a compression test. In fact, I had planned to, but my compression gauge won't go down into the plug holes. I need to get an extension for it.
#35
#36
Re: Scanner - Yeah, by that, I just meant something able to read live data via the OBD II port. This is as opposed to a code reader, a much simpler device which can only (wait for it...) read codes and not much else.
What is the scanner saying for fuel pressure? The mechanical gauge shows 38, right?
#37
I would measure the fuel pressure with a fuel pressure tester. You have a test port on the passenger side fuel rail. These can be borrowed for free from the parts stores but you might need to track down an adapter? My personal gauge had the correct fitting.
You need 55 psi as has been posted. If less you will have problems even if you can get the car started.
1. Fuel pressure with key on-engine off. If NOT 55 psi or so. Cycle key off and on several times without cranking the engine. What is that number?
2. If you can get the car started post the running fuel pressure. As stated above it's referenced to the intake vacuum/pressure and should jump around as you rev the motor.
3. I was able to drive around with the mechanical fuel pressure gauge installed. Ran the hose up by the wipers and closed the hood.
You should have codes if the fuel pressure is too high or too low but I did not see that you posted any codes?
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You need 55 psi as has been posted. If less you will have problems even if you can get the car started.
1. Fuel pressure with key on-engine off. If NOT 55 psi or so. Cycle key off and on several times without cranking the engine. What is that number?
2. If you can get the car started post the running fuel pressure. As stated above it's referenced to the intake vacuum/pressure and should jump around as you rev the motor.
3. I was able to drive around with the mechanical fuel pressure gauge installed. Ran the hose up by the wipers and closed the hood.
You should have codes if the fuel pressure is too high or too low but I did not see that you posted any codes?
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#38
I would measure the fuel pressure with a fuel pressure tester. You have a test port on the passenger side fuel rail. These can be borrowed for free from the parts stores but you might need to track down an adapter? My personal gauge had the correct fitting.
You need 55 psi as has been posted. If less you will have problems even if you can get the car started.
1. Fuel pressure with key on-engine off. If NOT 55 psi or so. Cycle key off and on several times without cranking the engine. What is that number?
2. If you can get the car started post the running fuel pressure. As stated above it's referenced to the intake vacuum/pressure and should jump around as you rev the motor.
3. I was able to drive around with the mechanical fuel pressure gauge installed. Ran the hose up by the wipers and closed the hood.
You should have codes if the fuel pressure is too high or too low but I did not see that you posted any codes?
.
.
.
You need 55 psi as has been posted. If less you will have problems even if you can get the car started.
1. Fuel pressure with key on-engine off. If NOT 55 psi or so. Cycle key off and on several times without cranking the engine. What is that number?
2. If you can get the car started post the running fuel pressure. As stated above it's referenced to the intake vacuum/pressure and should jump around as you rev the motor.
3. I was able to drive around with the mechanical fuel pressure gauge installed. Ran the hose up by the wipers and closed the hood.
You should have codes if the fuel pressure is too high or too low but I did not see that you posted any codes?
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I've been super-busy, and haven't been able to get back to it and swap out the fuel pressure sensor. If I can get it started with that, I'll run the mechanical gauge on it while I drive around. There's a moderate chance I'll be replacing the fuel pump as well. Some major changes are coming down the pike in my life that will make me more able to tolerate my beautiful car's eccentricities. This is a good thing
#39
Ok, update time:
- swapped in the OEM FPS. Still doesn't start. However, using my scan tool, I can see the fuel pressure - as delivered by the new FPS - is 60psi and solid when cranking. When I stop cranking the pressure drops to about 56psi and then ever so slowly drops down a 1/10 of a psi every minute or so.
I think my mechanical fuel pressure gauge might be shot. Well, that and perhaps there is some kind of issue on the right side of the engine (where the schraeder valve is).
I get a very strong fuel smell when cranking. This isn't a new behavior. This has been a constant throughout this adventure.
Things I haven't done yet:
- pull a plug and coil, ground it and crank to make sure I'm getting spark.
- compression test
- smoke test
I have a smoke tester device coming tomorrow. There is an existing evap leak issue, but I don't think that could be causing this no-start condition, could it?
Ken
- swapped in the OEM FPS. Still doesn't start. However, using my scan tool, I can see the fuel pressure - as delivered by the new FPS - is 60psi and solid when cranking. When I stop cranking the pressure drops to about 56psi and then ever so slowly drops down a 1/10 of a psi every minute or so.
I think my mechanical fuel pressure gauge might be shot. Well, that and perhaps there is some kind of issue on the right side of the engine (where the schraeder valve is).
I get a very strong fuel smell when cranking. This isn't a new behavior. This has been a constant throughout this adventure.
Things I haven't done yet:
- pull a plug and coil, ground it and crank to make sure I'm getting spark.
- compression test
- smoke test
I have a smoke tester device coming tomorrow. There is an existing evap leak issue, but I don't think that could be causing this no-start condition, could it?
Ken
#40