Topic: HELP: truck will not start when warm!

[2slow4you]

This problem of mine has been getting progressivly worse. After driving for awhile I will turn off the truck only to try and start it a couple mins/hour later to find it will not start. It cranks no problem but it won't catch. It's getting plenty of fuel, bran new NGK plugs/wires, Fuel pump, fuel filter, air filter, PCV, vac advance module... It's a 1985 22r with 135k miles. The truck starts just fine if its cold and only does this some times. Its definatly Heat related, I just can't figure out what it is. Coil/Igniter...? Compression is 175psi across the board, plugs look good, the only thing i could find out of the norm is the new Carquest Cap/Rotor is coroded at the contact points. This couldn't cause a non start prob though... right?

Anyhelp would be much appreciated!

[84xcab]

Mine did they same thing for a while, my spark plugs were fouled and my tstat was shot causing it to over heat. Don't know the exact cause, but switched them both out and no more problem.

[2slow4you [OP]]

Mine did they same thing for a while, my spark plugs were fouled and my tstat was shot causing it to over heat. Don't know the exact cause, but switched them both out and no more problem.

Were you getting a high reading on the gauge? Mine has yet to be hot. Plugs are all fine. Any other ideas?

[Tallchevy]

the only thing i could find out of the norm is the new Carquest Cap/Rotor is coroded at the contact points.

Coroded contacts will give you a no start. Clean the contacts or even better, replace the cap & rotor 

[RN37DD]

shouldn't matter.. but it might be a good idea to use a Toyota cap and rotor. if an early 20r rotor got mixed up in the box, it could cause a problem. the 22r has a carburetor, so  check your choke operation too. it should be open when the engine is warm. if it is open and hard to start. try closing it and try to start the engine. if it fires up, it may be a fuel problem. dirt,water or crud in the carburetors normal run circuits.

[2slow4you [OP]]

awesome, thanks guys, i didn't think the cap/rotor would do that but I guess it makes sense. I will check the choke later tonight.

[toyyota]

You may want to run the engine, remove the air cleaner, and look down the carb with a flash light. look for fuel bleeding into the manafold, flooding the engine, causing a hard start. Float and needle may need to be replaced, still available from Toyota, although not cheep.

[79coyotefrg]

stock carbs have a fuel cut solenoid that works off vacuum switches on the pass side inner fender, if the switch or vac lines are bad it will cause what you describe

[2slow4you [OP]]

stock carbs have a fuel cut solenoid that works off vacuum switches on the pass side inner fender, if the switch or vac lines are bad it will cause what you describe

Looks like its time to replace all of the vac lines and see what happens. Iam getting some oil residue from one of the vac switches, I guess that doesn't help. Perhaps that is cause it to close off/not close. Thanks

[swervin curvin]

have you replaced the timing chain? my 85 22r 2wd pickup was doing the same thing and i talked to a mechanic he said to try turning the harmonic balancer back as to take slack out of the timing chain but it jumped time b4 i could try this. but i kinda scratched my head to this cuz if it was a timing issue it would happen when its cold or at normal temp. but any way with 20r and 22r engines i recommend replacing the timing chain between 125k and 135k or more depending on proper oil changes (i know off subject sorry)

[2slow4you [OP]]

The timing chain was replaces only 10k ago using all OEM parts. I went to Napa today and purchased new Vac hoses so we'll see if that changes anything. Wish me luck. 

[hammer]

This is a longshot but on high milage engines the valve seats can start to wear away and a ring can be worn in the valve face.  This problem is know as beat in.   More of a diesel engine thing really.

 if the valve seats get beat in enough or if enough of a groove gets worn into the valve face( all the way around) this can make the valve lash clearances get extremely tight. 

Once the engine is hot the valve lash may become less than zero which in turn would prevent the valve from completely closing untill the engine cools down restores the valve-tappet clearence enough for the valve to comletely shut and restore compression to normal numbers. 

Or maybe someone just did a bad valve adjustment on it and set everything too tight.

Or maybe im just scraping thr bottom of the idea barrel. but nun the less it wouldnt hurt to break out the feeler guages and chech since its good maintianence anyways

good luck and hopefully its something simpler

[Plekto]

Sounds like vapor lock or something with the carbs to me.  My old Mercedes years ago did this as well.  If you smell gas after a bit, it's def flooded and needs to dry out.

[hammer]

Coil.

sometimes when they are on their way out they will act up only when they are hot.