Won't start after its hot/warmed up.

[EN*PN78]

Well the weather has been nice in Portland. In fact its been hot out.
Problem is my truck will start in the morning, OK no problem but after I drive to work or park somewhere that is about 80 degrees outside my truck doesn't want to crank over with the turn of the key. I can run a screw driver over the starter solenoid contacts and she fires right up with the key turned on and in park. (old car trick) We have a new starter and solenoid. I moved the hot wires around the engine because I thought they where getting to hot, because they ran down the engine over the intake and exhaust manifolds (stupid anyways). I've checked all my wires on the starter and alternator cleaned my battery contacts. Its a automatic non tilt. Inline 250 six.
Is it my neutral safety switch? If I yank and bang the shifter into park it doesn't help either. Or try to start it in other positions on the shifting patterns.
Ignition bad, going bad? Thats my guess. Its been slowly getting worse.
Please Help
Thank You

[70LonghornCST]

I know that the previous owner of my truck (1970) was having problems with the exhaust manifold not only damaging the starter, but also the wiring. You may have a problem in the wire itself that runs from the starter to the firewall...just a guess.

[old Rusty C10]

im wondering if the fusible link is bad or if the battery cable is touching the manifold.. it wouldnt be a neutral safety switch .. im wondering if theres a problem in the ignition switch tho that would be last on the list

[EN*PN78]

UPDATE:
Well I looks like I figured it out. Its been getting worse and worse. I'm sick of opening my hood to start the truck.
Heres what I did:
Checked all my battery cables and All my main power lines, Radio included. No problems
Checked to make sure I wasn't have a grounding issue or volt drop. I used a search on here for that. Nothing
The neutral saftey switch seemed to work just fine. Because it would start off the solenoid.
It seemed wierd and sometimes my ignition switch wouldn't work and then it would weither or not is was hot outside. At least was 60 degress one morning and it wouldn't start off the switch. But when it was hot no luck at all.
So I talked it with a friend who has a 74 truck and decided to replace the Ignition Switch.
So far so good no problems on wanting to start it up. I had a typical day of running around pickup parts for a job and the truck started everytime. I believe the heat was effecting the switch and it was going bad.

Note: You have to drop your column to get the Ignition Switch back in with the wires on it. It made it easier to see what I was doing also. Watch out for the fragile cable for the gear indicator below the gauges and above the column disconnect that as well.

[screwballl]

I had a similar problem but mine would die after 1-20 minutes even if I was driving... I had to replace the module in the distributor... may be worth checking at least...

[slash crashley]

i've been having this problem lately too. (1982 250 I6) it fires right up the first thing in the morning. i run it for a 1/2 hour or so and it's difficult to restart. one time i got a boost and it roared to life. the next day it started fine.

i was thinking it was an alternator or starter issue since the battery is barely 6 mos old. i use a batt. kill switch whenever i'm parked for the day. i'll look into the things mentioned in here and see if that remedies it.

a buddy at work is parting out a 93 chev 1500 350/400. i'm pretty sure the alternator will work with my truck but i'm not sure about the starter. anyone know for sure?

[dammitmitchell]

starter solenoid dude...
its going bad,it happens and it sucks and i know...
but when it heats up and gets old it basically "breaks continuity" inside of the circuit (solenoid) and you dont have a working starter until everything cools down..
but on a lighter note it could just be a loose starter connection also,
check the wires for free movement, and if they dont
then replace the starter

and it wont hurt to clean the ignition also pull apart what you need to so you dont leave all the crud in the steering column, then spray off the contacts with CONTACT CLEANER
and remember dont run electricity through the ignition until the stuff is dry
good luck

[Samina]

Originally Posted by dammitmitchell

starter solenoid dude...
good luck

Thanks to this suggestion by you, it helped solved the problem of our '90 Mitsubishi Mighty Max truck.
The scenario: I drive truck to local animal shelter once a week. It starts fine in early morning. I take a dog for a walk in park, get back after 45 minutes, it's hot out by now and sometimes it would start and but sometimes it would not crank. When I did get it started I had to run to town for a few groceries, and it did the same thing. I told my husband and he guessed that the ignition switch was going bad; worn. I then did a search for the temperature thing and no crank and found this thread and one other person at another forum that mentioned it could be the starter itself. Since I'd removed this starter years ago to have it tested I decided to go with the starter being the problem, so I removed it and took it to advanced auto. The gear wheel wasn't pulling out, guy said it was bad. I think my husband said that it meant the relays were bad. When my husband gets home, he'll have to check if I got the bolts tightened as it wasn't easy getting them out, especially with the tools I am using (he's got the metric set I originally used to remove it - yep, the right tools can make a big difference and keep tears away). And maybe he can clean the ignition contacts as it sounds like a good idea to do on such an old vehicle.
Anyway, just to say, thank you, dammitmitchell! The internet can be invaluable for solving auto problems. It sure beats taking it to a mechanic.
Regards, Samina

[1tonchevy]

had the same issue my starter was getting "heat soaked" changed the starter issue went away.