... another hard starting when hot thread Topic is solved

highmiles · Post by **highmiles** » 12 Jul 2021, 08:26

To date I have combed back through all the “difficult starting” threads and have done all the checks and parts replacements that I can think of to no avail, so looking for any new thoughts and bright ideas.

Car History: 2001 S60 T5, 5 Speed manual transmission, 175,000 miles. I bought it with seized water pump and associated timing belt failure with bent valves etc. I rebuilt the top end, new timing parts etc. and planned to sell it. My son liked the car, so we have kept it and he uses it for his commute to high school, work etc. The hard starting occurs only as the car warms up, it always starts from cold and once running, even when hot, runs great, pulls strongly, idles evenly. The car always cranks well. A few weeks ago my son could not get it to start at all, he got a ride and we picked the car up later when it had cooled. Since then, I have been trying to pick off the possibilities. The car generally does not throw a check engine light (my VIDA/Dice has crapped out so only reading generic codes,) but occasionally will show a crank sensor error (P0335) at no start, but almost always clears itself if the car does start.
Work to date, not necessarily in order:
• Replaced crank shaft sensor with new, no change. Note, the crank shaft sensor error has appeared both before and now after the replacement.
• Replaced cam shaft sensor with spare, no change.
• Replaced key chip antenna, no change (went with this after getting the immobilizer message… so much hope… so much disappointment…)
• Checked fuel pressure, holds at 50 or so while cranking, running and after shut down.
• Pulled a few spark plugs, they look excellent.
• Pulled the fuel injector rail, no apparent leaking.
• Checked battery voltage while cranking, drops only to 11.5 or so. Charging correctly while running. Hooked up a spare battery just to see, no change.
• Removed, cleaned and reinstalled the following grounds, engine block to body, three at fuse box to body, at the transmission, no change
• Conducted glove test, the car fails this, I didn’t replace these components when I did the motor, so there is work to be done here, but I would not imagine this is the issue.

Some thoughts:
• Yesterday I got the P0335 code again. But I have started to think these are anomalies. Maybe…
• I tried to understand the input voltage to the crank sensor. I did not try to get any live readings, didn’t have the materials to rig that up using a multi-meter. Did test the input with car in “run” and feel like I was getting 5v at both wires? This didn’t seem right from what I could read, but I never found specific values for this model. Tracing these wires out might be the next step? Again, does not seem to affect running condition.
• I have been avoiding buying another VIDA/Dice set up. It appears my software is fine, but the hardware is no longer communicating. If I need this get to the heart of the matter I will suck it up and get another one.
• Tracing out the crank sensor wires will be easier if I remove all the intake stuff so will be right at the PCV parts, so might as well order that up.

Look forward to hearing input from crowd, thanks in advance.

Post by **jonesg** » 12 Jul 2021, 10:09

are the plugs sparking during no start cranking?
do the injectors click when it won't start?
That would coincide with your suspicion of the crank sensor circuitry.
VIDA would really help.

Post by **vtl** » 12 Jul 2021, 14:18

Run your own crankshaft sensor's wires to ECM as far away from the starter as possible. Or replace the starter, they are cheap. I have this one: https://www.amazon.com/gp/product/B007Y85MFE

highmiles · Post by **highmiles** » 12 Jul 2021, 14:42

jonesg wrote: ↑12 Jul 2021, 10:09 are the plugs sparking during no start cranking?
do the injectors click when it won't start?
That would coincide with your suspicion of the crank sensor circuitry.
VIDA would really help.

Thanks, that is good basic trouble shooting, something I have overlooked. Do we know if no input from the crank shaft sensor kills spark and fuel? I know when I unplug it and the engine is running it dies right away.

highmiles · Post by **highmiles** » 12 Jul 2021, 14:43

vtl wrote: ↑12 Jul 2021, 14:18 Run your own crankshaft sensor's wires to ECM as far away from the starter as possible. Or replace the starter, they are cheap. I have this one: https://www.amazon.com/gp/product/B007Y85MFE

Thanks, started is good, turns the motor over well at all times. Sounds like tracing those wires is a good idea. I suspect I would need to pull the ECM to test continuity back that far?

Post by **vtl** » 12 Jul 2021, 14:44

highmiles wrote: ↑12 Jul 2021, 14:42 Do we know if no input from the crank shaft sensor kills spark and fuel?

Yes. An old starter creates a lot of interference in CPS wires that are routed nearby. Either replace the starter, or reroute the wires (put a new ones, as old ones are hidden in the loom).

highmiles · Post by **highmiles** » 13 Jul 2021, 08:26

vtl wrote: ↑12 Jul 2021, 14:44
highmiles wrote: ↑12 Jul 2021, 14:42 Do we know if no input from the crank shaft sensor kills spark and fuel?
Yes. An old starter creates a lot of interference in CPS wires that are routed nearby. Either replace the starter, or reroute the wires (put a new ones, as old ones are hidden in the loom).

Ah, now I get it, never heard of that issue! Well, that gives me "the next thing" to do. Might as well order up the PCV parts as it will be easier to work on the wiring in that area if I pull off the intake. Thanks again!

Post by **vtl** » 13 Jul 2021, 08:41

highmiles wrote: ↑13 Jul 2021, 08:26 Ah, now I get it, never heard of that issue! Well, that gives me "the next thing" to do. Might as well order up the PCV parts as it will be easier to work on the wiring in that area if I pull off the intake. Thanks again!

That also makes it easier to replace the starter, since it gives you the first signs it's on its last stretch. Starters are cheap, cheaper than flatbed =)

highmiles · Post by **highmiles** » 19 Jul 2021, 09:16

Just a brief update to say thanks for the guidance on this problem. Ordered the starter noted in the thread, it arrived very quickly. We got it installed yesterday with only the typical issue with contorting one self to blindly attach and clamp the intake hose to the throttle body and the car fired right up. Drove it around for a while and did several additional starts and all good.
This was a great trouble shooting exercise.

joaoreis00 · Post by **joaoreis00** » 11 Sep 2022, 04:43

highmiles wrote: ↑19 Jul 2021, 09:16 Just a brief update to say thanks for the guidance on this problem. Ordered the starter noted in the thread, it arrived very quickly. We got it installed yesterday with only the typical issue with contorting one self to blindly attach and clamp the intake hose to the throttle body and the car fired right up. Drove it around for a while and did several additional starts and all good.
This was a great trouble shooting exercise.

I've been experienced the same problem as you. did the new starter solve the problem for good?