Weak Hot Start

Well after much work I've gotten the truck better but still something is off. Originally it would not start or would long crank. The fuel system has had many changes that helped. Below are all the components that have helped and been replaced.
- Fuel Sending Unit
- Fuel Pressure Regulator
- Fuel Pulsation Dampener
- Spark Plugs
- Battery
- Starter Solenoid (components bought and rebuilt by me)
- Starter Relay (intermittent operation)

What I'm thinking now is I have a timing issue I know the coolant temp sensor has a big roll to play with this as does the MAF and O2.
Over 191k miles on it now.

Any ideas what I should try next?

 

what does Hot Start mean?

 

As if you ran it down the road at full operating temperature and shut it down, then attempted to restart the engine after a few minutes to 15 minutes of sitting.

 

is it sluggish to turn the engine over or doe it just take a long time for it to start?

 

Weak not so much longer or sluggish.

 

battery or starter would be my guess...

 

Starter rebuilt and strong. Battery is new. Installed yesterday evening. The Optima was at 20% after 5 years.

 

You said you rebuilt the stater solenoid but thats not the whole starter...what did you change in the starter?

 

Nothing to change within the starter. Nippondenso reduction starter. Brushes were still in spec as we're the bushings. Armature checked out and so did the stator.

When cold after an overnight soak it fires up perfect.

 

first battery,then starter since you've already changed out the contacts in the solenoid(starter) I would bet battery which can easily be checked for free or multimeter.

 

maybe the pos. and neg. battery cables need replacing(unusual for Toyotas)? or new/clean terminals, also maybe the alternator is ready to take a shit

 

It has been replaced. Optima was down to 20%.
Multimeter can only give you voltage. The amperage can be low while the battery retains full 12.6 volts.

 

Alternator still functions and has no effect on starting when warm.
Terminals are clean and the cables have low resistance values.

 

there nothing left to check if it starts and runs then alls good

 

Well starts weak is something wrong so. I'll continue to look. I'm thinking ignition timing related.

 

how many miles? on it

 

Please read original post.
Over 191 K

 

My 2006 2.7 has a weird hot start too, maybe not exactly what you are experiencing but still strange. It is in great shape, starts fine cold and runs fine cold or hot (once it is started). But when it's at full temp and I go to restart it, it takes a few extra cranks to fire, and maybe 40% of the time it will stumble and die, requiring another start attempt. But it always starts on the 2nd hot start attempt. Some people have said this is normal for these trucks because of the way Toyota programmed the computers and fuel delivery... the hot start function is just dumb. I've never had a vehicle that behaved this way on hot start. Hope this helps you... ignore if it doesn't.

 

Mine is nearly identical to that. I'm beginning to think the coolant temp sensor is shot. Going to test it tonight cold then again hot.

 

Subed because the wife's '97 has the same issue.