cold natured 350 tbi

[jaxdad]

my 350 tbi is extreamly cold natured. This thing runs great once its had time to warm up to about 150°. I think I may have a temp wire for the timing unpluged but I'm not sure where to look. Any ideas if it could be anything else? Its just had a tune up.

 

[Swims350]

temp wire for timing? never heard of such a thing.

my 88 tbi 350 is almost the same, it has to warm up for 5-10 minutes or else it misses kinda bad, and bogs.

as for a timing wire I know of a EST wire, that's the one you unplug to set the timing then plug it back in.

 

[bucket]

Could be a number of things. Idle air control motor comes to mind, it can cause the motor to idle too low on a cold start if it's not working. Seems like mine craps out about once a year.

Check Engine light on? Does it even work?

 

[skysurfer]

Well, it is Winter.

If it's a year round thing does it have the correct 195* thermostat and does it work? If you're not sure, replace it. Get a good one, I like the ones made by Robert Shaw.

You can swap out the oem 2 wire O2 sensor for a self heating 3 wire which will allow the ecm to go into closed loop sooner. Part # AFS-74

If you're still running the original air cleaner and exhaust manifolds is the heat riser tube intact? Probably not, they get lost pretty quick in states without emissions testing. That by itself won't help much, but it couldn't hurt to hook it up.

 

[bucket]

Doesn't matter how cold it gets, it should still fire up and run well, IMHO. Thermac, O2, and thermostat don't matter on a cold start, just once the motor starts to warm up they will help it run more optimal.

For what it's worth, I run a 180* stat and the heat tube for the thermac is long gone. It starts fine and runs well, even in the dead of winter. I do have a heated O2 though.

 

[skysurfer]

If the thermostat is stuck open it would make a difference.

 

[bucket]

If the thermostat is stuck open it would make a difference.

Not on a cold start though. The coolant temp is going to start out the same no matter what.

 

[skysurfer]

Wait a minute... you're talking cold start and the op is saying cold blooded, which to me means it's slow to warm up. Are we talking about the same thing?

 

[bucket]

Wait a minute... you're talking cold start and the op is saying cold blooded, which to me means it's slow to warm up. Are we talking about the same thing?

Lol, I was talking about the wrong thing. Sorry

*edit* I blame Swims for throwing me off, with his talk of missing and bogging and whatnot. Haha.

 

[skysurfer]

Flipping through the Haynes manual I see it says that if the coolant temp sensor on the intake is bad it will throw a code 14 or 15. Something else to check.

 

[towman]

i would suspect the coolant sensor that is beiside the thermostat, they usualy do not throw a code and can make it run poor, best if put on a scanner to see what it is reading but i have also found of you unplug it the truck will usualy run correct if the part is bad

 

[jaxdad]

thanks for the input. This beast has headers and the thermostat is new. Is the coolant sensor in an obvious spot? No codes

 

[Bagged Dually]

Should be right on the front of the intake manifold. Mines a 2 wire plug, and the plug was very brittle. I ended up crumbling mine it was so harden and old. My truck was doing the same as yours before I replaced it and now it seems to be better. Hope this helps

 

[Swims350]

don't blame me, mines the same as his, it starts fine being cold, just takes a bit to warm up and work, if you give it time to warm up then it's fine. But if you fire it up and only give it a minute or two and try to drive it runs bad.

 

[dhamp]

Mine does it too, but I'd attributed it to being in need of a tune up. Maybe not though......hmmmmmmm. It's really bad though. Just a little miss here and there. By the time I make it to the first red light (about 1/2 mile) it has cleared up.