Will a CEL come on......

[95Z71Mike]

Got it set to 6* advance today. And it runs like a new truck! Its amazing what timing can do.

Before it had barely any power and I would not dare to pass someone. And when I got on it to go up a hill or something it would ping and tick horribly.

NOW, it has plenty of power and doesn't make any weird noises.

It still doesn't like for me to feather the gas though, it sounds like its flooding and shudders and drops rpms for a second but comes right back up when I let the gas go or give it more.

 

[98_k1500]

Bought a timing light gun today, unpluged the wire and started the truck. After it warmed up I put the gun to it and couldn't see the line on the balancer. Untill I turned the gun advance, I had to turn the gun up to 21* to get the line to line up with the 0* on the pointer.

Sounds like your balancer rubber has slipped...

 

[someotherguy]

If base timing at 6° has it running reasonably well then I wouldn't suspect a slipped balancer, I'd think more likely someone previously tried to adjust the base timing without disconnecting the bypass wire first.

At any rate I'd set it back to 0° factory spec, even a couple degrees advanced will cause knock counts from pinging you can't even hear yourself, but the knock sensor does, and makes the PCM pull out timing advance - costing you power.

To answer the original question about whether the coolant temperature sensor will set a CEL: almost never unless it's shorted out. They can get really, really bad, to the point of fuel-fouling your plugs and stalling the engine, and not have a CEL. If you're suspicious of it just change it out. They should be changed semi-regularly IMO due to how they go bad with age, fail gradually, generally won't set a CEL and you don't know the thing is bad until it's gotten really bad.

Check MAP sensor vacuum fitting at the rear of the TBI, the boot often hardens and doesn't seal well anymore. Low vacuum reading from this will cause a rich condition too...and again, won't set a CEL unless it's really bad.

Richard

 

[95Z71Mike]

Thanks guys.

I'm going to change my Coolant temp sensor and sender (since my gauge isn't working good either)

After that if its still acting up a little I'll check the MAP sensor

 

[cjman250]

If it is a map sensor they are only like $10

 

[95Z71Mike]

Where do you get your parts from CJman? I've never seen them that cheap.