Hard to start after long trips.

[r32flow]

Hey guys, first post here.

Just bought my 98 k1500 350 a couple weeks ago. It left me stranded the first week. So I went and replaced the whole ignition system. As the distributor cap was trashed.

After that the truck only needed a half a crank to start up. But recently it doesn't like to start after long trips. I'm talking about an hour or more trip. It cranks and sputters but won't start. After cranking a couple times it will fire. Yesterday was the worst. I had to crank it at least 5 times to start. Same deal. Would sputter and die. But finally fired and sounded like crap. Almost like a missfire. After warming up the idle smoothed.

So I'm anxious to hear if you guys have any suggestions. I don't want to throw money at parts that might not fix my issue.

What's weird is when it's cold and sits over night, it fires up no issues. I'm very confused.

Thank you guys for any help you can give me.

 

[movietvet]

Welcome to the forum from Oregon

When you say "whole ignition system", can you list everything replaced and what else may have been done, like adjustments and wire splicing and just anything.

Also, when you say after long trips, are you talking restart after 5 minutes, 15, 30, 1 hour, 2 hours? It sounds like you have resistance in the ignition circuit or a fuel delivery problem. Do you turn the key on and try to start immediately and have the problem or do you do a KOEO and let fuel prime for 2-5 seconds? Might need to attach a fuel pressure gauge and see what the fuel pump is doing when the problem occurs. Use a spark tester and see what it looks like when the problem occurs. Sounds like you can duplicate the problem when you want to.

 

[r32flow]

Cap, rotor, coil, wires, plugs.

I also replaced the starter, and seafoamed it. That's about it.

I really should scan it, just haven't had the time.

 

[r32flow]

OK so yesterday I drove an hour and 30 min. Parked it. Then probably came back an hour later, maybe slightly more and had this issue. Also yes, I turn the key toward first and wait a moment before starting.

What's weird is if it sits over night, it's never an issue. She doesn't like running long trips lol. Truthfully I don't either lol.

 

[rebelyell]

Cap, rotor, coil, wires, plugs.

I also replaced the starter, and seafoamed it. That's about it.

I really should scan it, just haven't had the time.

Yes, you should scan trouble codes to help focus further diagnoses.

Also, check the distributor shaft for excessive play.

Aside from that, suggest you next R&R ignition module; ensuring you also renew the module's heat sink transfer compound/grease. Arctic Silver is a good choice; it's cheap & easy on amazombie and Not the same thing as dielectric grease. Good luck with your project.

** Also, check the small air vents in base of distributor; it's common issue they become clogged and No air flow thru dist. That often leads to oxidation inside dist & misfiring.

 

[Supercharged111]

From the hip, sounds like it could be a leaking fuel pressure regulator and/or leaking injector poppet. Try giving it half throttle when it's being a pig and see if it starts easier that way. If you have a fuel pressure gauge, check and see if pressure drops like a rock after you shut it down too

 

[r32flow]

That's exactly what I have to do to get it started. Give it half throttle and it starts but runs kind of rough until it warm.

 

[r32flow]

I'm out of town right now. So hopefully the truck gets me home tomorrow and I can scan it. Wish me luck.

 

[east302]

With the scanner, see what the coolant temperature sensor (ECT) is reporting. It should be around ambient when cold and up to the thermostat setpoint. If it’s negative 40 or something odd, the sensor or its wiring would be suspect and can cause hard hot-starts.

Holding down the gas while cranking is clear flood mode - it temporarily pauses injector flow and is a workaround when the ECT sensor is causing issues.

 

[Supercharged111]

With the scanner, see what the coolant temperature sensor (ECT) is reporting. It should be around ambient when cold and up to the thermostat setpoint. If it’s negative 40 or something odd, the sensor or its wiring would be suspect and can cause hard hot-starts.

Holding down the gas while cranking is clear flood mode - it temporarily pauses injector flow and is a workaround when the ECT sensor is causing issues.

That's only if you floor it.