f1racer328
Full Access Member
I’ll go check mine again, after driving 30 minutes.
Long crank, no faults
- Thread starter Jimmy Brooks
- Start date
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Jimmy Brooks
Full Access Member
Might’ve been a false alarm, whenever I turn off the ignition it likes to say 419, but as soon as I turn the ignition back on it reads the same as the ambient. Does anyone else’s do this as well?
Jimmy Brooks
Full Access Member
Here’s a couple of cold starts. Pretty sure the starter is healthy considering it’s still working but not sure if it has much more life in it if it has to crank extra long every morning.
Long crank:
Normal crank:
Long crank:
Normal crank:
jlglr4
Full Access Member
11.7v or even towards 12v is not good with key off and all systems down. You should be seeing 12.6v. When testing, pop the hood and let it set key off for a good 10 min so all the systems shut down completely. You can also set your voltmeter to max/min, hook it up and start the car. then check the min volts. should not drop below about 9v.
To my ears, that crank sounds a little weak, but maybe due to battery rather than starter motor. Not saying its causing the long crank, but might be one problem to address.
Jimmy Brooks
Full Access Member
At this point I wouldn’t be surprised if it was at battery issue. Everything else seems to be working fine with no codes, no fuel issues etc. plus I’ve seen some weird behavior from this battery too, when I was off-roading a couple of months back with my light bad fog lights high beams etc all on I was seeing 12V on the IID tool. My battery charge was dropping too. I turned all the systems and lights off and it was still 12V-11.7ish. Let the car sit over night and came back and volts were normal at 13.2-13.7v. I’ve never had that until they replaced the battery. They also told me they put a “better battery” or more powerful battery in the car and that my last one was cheap. I’ll take a photo of the type of battery they dropped in it when I do the test. Do you think it’s better to do the test on a cold start when it usually cranks long? If I do it after the car had been started it’ll normally fire right up.
Jimmy Brooks
Full Access Member
voltags did another one of its weird trends. After a long crank the Voltage displays 12.7 without the heater on, with the heater it shows 12.5. Here’s another video of my voltage changing with revs yet when it’s warm it’s perfectly normal. The second photo is after a short 5 mile drive. It’s like as soon as it’s warmed up it’s fine. Next cold start where the voltage is weird I’ll check the alternator load, didn’t think of doing that until I was driving. (Load might be higher due to the sub I have in my car)
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jlglr4
Full Access Member
I don’t really trust the voltage displayed on the dash readout, but probably gives you an approximation of your charging system voltage. Your probably seeing 12.7 show up after cranking because the alternator just gave the system a boost. Normal that the heater motor would bring that down.
With the engine running, the BMS is adjusting the charging to the battery, so hard to say what you are seeing, but in the old days it was perfectly normal to have an increase in voltage when you rev the engine. Normally, I see about 14v or higher with the engine running, which is the voltage seen at the battery when charging. Once that battery is fully charged, I think it will drop off.
But I don’t think any of these readings tell much about battery health. For a quick check on battery health, just use a multimeter to test the resting voltage, and then test the voltage drop with the max/min function on the voltmeter. What you are looking for is that instantaneous drop in voltage when the starter kicks in - you won’t see it on the dash readout or gap tool. If it drops below 9v, that‘s not a healthy battery.
With the engine running, the BMS is adjusting the charging to the battery, so hard to say what you are seeing, but in the old days it was perfectly normal to have an increase in voltage when you rev the engine. Normally, I see about 14v or higher with the engine running, which is the voltage seen at the battery when charging. Once that battery is fully charged, I think it will drop off.
But I don’t think any of these readings tell much about battery health. For a quick check on battery health, just use a multimeter to test the resting voltage, and then test the voltage drop with the max/min function on the voltmeter. What you are looking for is that instantaneous drop in voltage when the starter kicks in - you won’t see it on the dash readout or gap tool. If it drops below 9v, that‘s not a healthy battery.
Jimmy Brooks
Full Access Member
Haven’t done the multimeter yet but I don’t think it’s a battery issue. Hooked my jumper booster to the battery this morning and heard the starter crank faster then I had ever heard it, still took 2 6 second cranks to get her going. When it finally started revs jumped to 1300 rpm instead of jumping to 2000 at initial start.
Jimmy Brooks
Full Access Member
at a loss here at this point. Is it possible it could still be low pressure fuel pump even though the truck runs perfect once it’s started? Anyone else have any suggestions?
jlglr4
Full Access Member
Yeah - I don’t think battery would cause this issue, but it is maybe something to keep an eye on.
Thinking about the high RPMs at start, I wonder if you could have a vacuum leak. What are your RPMs at idle after it warms up? I would expect a lean code to show up, but you could check your fuel trims after the car is warmed up (so it’s in closed-loop fuel control). Check short term and long term fuel trims and see how they look.
The other thing that comes to mind is the throttle body plate and the throttle position sensor. A little gum in that throttle body can cause the butterfly to stick just a bit and throw things off. You could try cleaning it good with some carb cleaner if you haven‘t already. The TPS (integrated into the throttle body) also can cause these issues if it starts to go bad, but I’m not sure how to test it.
Thinking about the high RPMs at start, I wonder if you could have a vacuum leak. What are your RPMs at idle after it warms up? I would expect a lean code to show up, but you could check your fuel trims after the car is warmed up (so it’s in closed-loop fuel control). Check short term and long term fuel trims and see how they look.
The other thing that comes to mind is the throttle body plate and the throttle position sensor. A little gum in that throttle body can cause the butterfly to stick just a bit and throw things off. You could try cleaning it good with some carb cleaner if you haven‘t already. The TPS (integrated into the throttle body) also can cause these issues if it starts to go bad, but I’m not sure how to test it.
