High Idle tbi?

[Chevysilverado1995]

Hey guys, new here. I have a 95 1500 with a 350. bought it with a bad engine, didn't want to rebuild the engine and had a 79 350 with 10k miles on a rebuild in the shop. A little dye grinder action on the center 4 bolts of the intake and it was back on the road again. My brother bought a 90s dodge ram with a bad engine around 10 years ago, swapped a 350 tbi into it with a 5 speed and rigged up a "high idle" for when it was cold out. He can't remember exactly how he did it but it was something to do with the A/C wiring, had a switch to a ground tapped into the wiring somewhere in the mix and I don't want to just guess and fry the ecm. So, what I'm asking for is a wiring diagram? Somebody else that has done this before? I know it can't be just me and him that wanted a high idle for a tbi.

 

[tayto]

it will only increase idle 100-200 rpm unless you edit the calibration (burn a chip) i assume you have a '7427 pcm?

 

[Chevysilverado1995]

That’s all I’m lookin for, I have no clue on the pcm, does it say on it?

 

[tayto]

should say on it. there should also be a 4 letter code on it as well

 

[Chevysilverado1995]

That’s behind the glovebox kinda sorta isn’t it?

 

[Schurkey]

Why do you need to dick with the fast idle? GM has that in the OEM calibration.

These trucks ran just fine when started in the cold. If it doesn't run SPLENDIDLY, there's something WRONG.

 

[GoToGuy]

Why do you need a manual high idle switch, if it needs more rpm the ecm will manage it. Your not telling us something..

 

[smdk2500]

This is just a question for the more knowledgeable. Do the gas engine computers have a PTO connection on the computer? On the 6.5 platform there is one and when you apply 12v to it it will idle up to 1100 rpm on 94-95's and depending on how you wire it 1500-1600 on 96+. I know this is for getting more engine speed to run a PTO but some 6.5 guys do it for helping to warm the engine up faster and keep engine temps up during the winter. The 6.5 never had the elevated idle option like the newer diesels do.

 

[CRF450R]

On my 98 Z71 5.7 vortec I have a stick I put in-between the power seat and gas pedal and just keep moving the seat forward till I'm at about 1200-1300RPM to warm it up faster it gets dam cold here in Saskatchewan it can get down to almost -47c plus whatever the windchill does . So it's nice idle up a gas truck in them temps I hate getting Into cold vehicles absolutely hate it I'll show up late for work to get into a hot cab for all j care. I miss my 85 Silverado but I don't miss the pos carb job it had should of ls swapped it no more carb jobs for this guy ever again.

 

[tayto]

This is just a question for the more knowledgeable. Do the gas engine computers have a PTO connection on the computer? On the 6.5 platform there is one and when you apply 12v to it it will idle up to 1100 rpm on 94-95's and depending on how you wire it 1500-1600 on 96+. I know this is for getting more engine speed to run a PTO but some 6.5 guys do it for helping to warm the engine up faster and keep engine temps up during the winter. The 6.5 never had the elevated idle option like the newer diesels do.

i don't think this was a standard feature until the early 2000s. I know ford had it around this time IIRC. LIke I said, if you have hardware to edit the calibration, you can do a pseudo high idle switch by hijacking the AC control logic. Obviously if you want working AC this will be problem. If it were me I would use an idle speed solenoid like the carbs had to bump up idle speed for AC.