Tunda shuts off / starter motor won't turn operate

Hi guys,



I have searched the forums and did not find an answer to my problem.



I have a 2005 S Cab Tundra 4.7L 2WD with 123,786 miles.



A month ago I replaced the water pump, timing belt, pulleys, tensioner, drive belt, thermostat, and radiator.

The truck runs fine but has developed an intermittent problem, maybe more than one problem.



After driving some distance it occasionally will not crank (starter does not operate, solenoid clicks) after waiting 30 minutes or so it will crank right up and runs fine. This has happened several times.



Also the truck has shut off three times while driving at slow speeds, two times i had to let the truck sit for a while before the starter would operate, the third time the truck powered back up immediately while still rolling down the road.



I have replaced the starter last week with a new starter from NAPA, the exact same problems still exist.

The battery is hot, reading 12.48 volts and 14.5 volts with engine running.

The battery terminals were changed last week.

No codes thrown.



Usually the truck runs fine with full power and cranks just fine. This is just an occasional problem.



Any ideas?

Reply 1 : Tunda shuts off / starter motor won't turn operate

possably a bad or weak power relay in the front fuse box?? Not sure what else to look for..

Reply 2 : Tunda shuts off / starter motor won't turn operate

Okay, I will check the power relay.

I have checked the starter relay with a meter, it checks out which is not surprising since the truck usually cranks just fine.

Reply 3 : Tunda shuts off / starter motor won't turn operate

Okay, I was able to recreate the problem in the back yard, (starter does not operate).



My brother pulled the starter relay and checked the current going to the relay when I turn the ignition switch.



We got between 0 - 7 volts, it was a different reading each time I turned the key, we never got a full 12 volts.



This seems to be a problem in the starting / ignition switch circuit?

Reply 4 : Tunda shuts off / starter motor won't turn operate

Ummmm sounds like you have a bad ground or a bad connection in your fuses or relay box,do your head lights and dash lights all stay lit?

Reply 5 : Tunda shuts off / starter motor won't turn operate

Quote:

Originally Posted by yotatoter Ummmm sounds like you have a bad ground or a bad connection in your fuses or relay box,do your head lights and dash lights all stay lit?

Yes, all the lights, fan, wipers, AC, gauges, etc work fine 100% of the time, even when the truck won't crank.



I'm working through the trouble shooting flow chart now, checking Ignition switch, P/N switch, ECM, so on and so forth.

Reply 6 : Tunda shuts off / starter motor won't turn operate

sounds like it could still be your starter relay going bad,I would replace it and see what happens. I have seen bad relays do that>>

Reply 7 : Tunda shuts off / starter motor won't turn operate

Quote:

Originally Posted by yotatoter sounds like it could still be your starter relay going bad,I would replace it and see what happens. I have seen bad relays do that>>

Yes that's what I thought initially, but the relay is not receiving a full 12 volts from the starting circuit when the starter will not operate. The ohmmeter reads less that 8 volts in the relay socket when you try to crank the truck.

Reply 8 : Tunda shuts off / starter motor won't turn operate

Ohhhhhhhhhhh ,thats not good,have you tried putting the truck in nuetral to start it??

Reply 9 : Tunda shuts off / starter motor won't turn operate

Quote:

Originally Posted by yotatoter Ohhhhhhhhhhh ,thats not good,have you tried putting the truck in nuetral to start it??

Yep...tried that too.



Right now I'd run around naked and sing Waltzing Matilda if I could figure this out.

Reply 10 : Tunda shuts off / starter motor won't turn operate

I had the battery & alternator tested, they tested OK.



I have noticed that when I'm experiencing no power to the starter, the check engine lamp (MIL) does not light up as the ignition switch is turned. The light usually comes on as the switch is turned when the truck cranks normally, and goes off when the truck starts running.



In this case the light never comes on as usual at the same time I have no power to the starter.

Reply 11 : Tunda shuts off / starter motor won't turn operate

Was the starter you put in brand new or was a remanufactered. Sometimes the remanufactered starters can be junk streight from the box. I have had that happen to me a couple of times with a dodge and a chevy I once owned. Installed a reman and had the brushes fail on one and a baring go on the other all on first crank. Brand new are more expensive but at times can be worth the money.

Reply 12 : Tunda shuts off / starter motor won't turn operate

Yes the starter was brand new from NAPA, I had considered that the starter was still part of the problem although it doesn't explain the other symptoms.



On Wednesday the dealer, who had the truck since Monday, told me my ECU is bad and they are going to replace it, if it does not fix the problem they will remove it and I don't have to pay for the part.