will it throw a code

Hi Guys ,
Just wondering if there is any possiblity of codes being present and not setting of the ses light? 2000 Silvy with a 4.3 . 232,000 km. Fuel mileage is kind of lacking lately . truck runs well ,filters are three months old ,plugs and wires good. likely just the winter weather . Can`t get any free scans north of the border and was just thinking maybe should get it scanned when it goes in for service, any thoughts
Thanks Muff

The cold weather WILL definetly affect gas mileage. I live in winnipeg and it was -49ºc last week with the windchill and mid -20's to mid -30's for about 2 weeks and the gas mileage sucked.

So, what are you thinking, that it is cold enough that it is taking longer to get up to operating temperature to get optimal mileage? Kinda makes sense. Down south here we don't have that problem, so I would have no clue, but curious none the less.

So, what are you thinking, that it is cold enough that it is taking longer to get up to operating temperature to get optimal mileage? Kinda makes sense. Down south here we don't have that problem, so I would have no clue, but curious none the less.Wish we didn`t have that problem either ......LOL actually what I was thinking is . I was reading somewhere a while back about a bad coolant sensor and how it did not set off ses light . bad coolant sensor makes the engine run rich and burn more fuel. Just on a fishing expediton here looking for answers I guess .
Thanks Muff

Hi Guys ,
Just wondering if there is any possiblity of codes being present and not setting of the ses light? 2000 Silvy with a 4.3 . 232,000 km. Fuel mileage is kind of lacking lately . truck runs well ,filters are three months old ,plugs and wires good. likely just the winter weather . Can`t get any free scans north of the border and was just thinking maybe should get it scanned when it goes in for service, any thoughts
Thanks Muff

Some code turn on light and some do not also a good scanner may show memory codes or pending code.
If going in for service have someone that is trained in engine running problems.
Put it on a good engine capable scanner and read out both codes and sensor data.
Also get a readout on camshaft retard setting.
If over - 0r + plus 2-3 degrees reset it.
Does it have a K&N air filter or after market set up?
Good old AC delco plugs?
Also a good fuel pressure test may show something.
Good Luck and let us know how it goes.

Some code turn on light and some do not also a good scanner may show memory codes or pending code.
If going in for service have someone that is trained in engine running problems.
Put it on a good engine capable scanner and read out both codes and sensor data.
Also get a readout on camshaft retard setting.
If over - 0r + plus 2-3 degrees reset it.
Does it have a K&N air filter or after market set up?
Good old AC delco plugs?
Also a good fuel pressure test may show something.
Good Luck and let us know how it goes.thanks MT that`s the kind of I was looking for .Hate to walk up to service desk and say ummmm can you check this here thing-a-ma-jig.....lol. everything is stock and yes has ac plugs. Camshaft retard setting is that the same as timing only in different terms ? On ocassion when the engine is warm and I start it up engine lets out a clunk that would remind you of engine run on. I ve been told its pre-ignition and not to worry about it " all 4.3s do that ". Brothers 4.3 with 170,000 kms on it does not do it. any thoughts.

thanks MT that`s the kind of I was looking for .Hate to walk up to service desk and say ummmm can you check this here thing-a-ma-jig.....lol. everything is stock and yes has ac plugs. Camshaft retard setting is that the same as timing only in different terms ? On ocassion when the engine is warm and I start it up engine lets out a clunk that would remind you of engine run on. I ve been told its pre-ignition and not to worry about it " all 4.3s do that ". Brothers 4.3 with 170,000 kms on it does not do it. any thoughts.

The engine timing is not adjustable. It is set by the pcm and crankshaft sensor.
The camshaft retard setting is adjusted by turning the dist.
It is centering the dist rotor dead on to the dist cap plug wire terminal.
It has to be checked or read out on a scanner and is adjusted by turning the dist.
Should read less than -2 0r +2 degrees or degrees perfered
Pre-ign or diesel/run on after is caused by excessive carbon build up or engine idle to fast.

MT
pre igniton /run on dieseling does not occur,I was just making the comparison as to what it does on start up. you would almost think the engine was locking up for a split second. other than that it starts ok ????? Al tho timing is not adjustable ,does this sound like a timing issue. some may refer to it as piston slap i don`t know.

MT
pre igniton /run on dieseling does not occur,I was just making the comparison as to what it does on start up. you would almost think the engine was locking up for a split second. other than that it starts ok ????? Al tho timing is not adjustable ,does this sound like a timing issue. some may refer to it as piston slap i don`t know.

Ok I see now.
On start up.
Not a timing problem.
You might want to have them check the dist cap and rotor and the camshaft retard setting.
You could have a little spark jumping in there that could give you a kick back.
Just tell them what it is doing and ask for a factory trained engine performance trained tech not one of there grease monkeys.
Good luck

The cold weather WILL definetly affect gas mileage. I live in winnipeg and it was -49ºc last week with the windchill and mid -20's to mid -30's for about 2 weeks and the gas mileage sucked.
It was SO cold.

So, what are you thinking, that it is cold enough that it is taking longer to get up to operating temperature to get optimal mileage? Kinda makes sense. Down south here we don't have that problem, so I would have no clue, but curious none the less.

It is a bit of that as well as the air itself being so cold. I know that when the air is cold it is thinner than when warm and that may or may not have something to do with it. The mileage also sucks cause you have to let it idle for so long to get any heat, not to mention so that everything has a chance to warm up a bit. I mean think about it, would you want to run great in -49ºc weather lol.

It was SO cold.

By any chance do you live in Winterpeg ?

Hello MT- 2500
finally took the truck in for service and had camshaft re-tard checked. it was at 0 ??? Thought I`d post here so that you could re read the original post. Tech /grease monkey did say his partner did have to adjust dist on some other units but they were having no start related issues. Also had a code co265 stored in history and I do know that a while back (4-6wks ago) the abs light and park brake light came on when Moved the truck at work one day ,but has not come on since. No other codes in system

Hello MT- 2500
finally took the truck in for service and had camshaft re-tard checked. it was at 0 ??? Thought I`d post here so that you could re read the original post. Tech /grease monkey did say his partner did have to adjust dist on some other units but they were having no start related issues. Also had a code co265 stored in history and I do know that a while back (4-6wks ago) the abs light and park brake light came on when Moved the truck at work one day ,but has not come on since. No other codes in system



Thanks for posting back how it went.
No codes is good.
Cam retard at 0 degrees is real good.
The history code P0265 was a problem on injector no 2 circuit.
If running good and no check engine light now no problem.
If it is time to change plugs and or filters it might be a good time to do that.
and clean MAF sensor if you are still running the K&N filter.
Good luck
MT

So, what are you thinking, that it is cold enough that it is taking longer to get up to operating temperature to get optimal mileage? Kinda makes sense. Down south here we don't have that problem, so I would have no clue, but curious none the less.

One other thing to remember about crappy milage in the winter months..... They change the fuel for us northerners to a winter formula. (so I've been told) More alcohol=less mileage. I did a maintenance routine in the fall. Changed all the filters, and all the fluids. Changed engine oil from castrol regular oil to Mobil One. Did the works, even put a tonue cover over the bed to keep the weather out. Felt real good..... Then checked the milage expecting an increase.... it dropped by 3mpg. :banghead: Hoping it will be better in the spring.