91 silverado guzzling gas?

Question

got a 91 silverado.....getting the crappiest gas mileage ever.....when i start it....a real strong exhaust smell comes from the pipes......also seems like the motor is under a load when i drive it, the motor is working extra hard

Answer 1

you might want to check the timing chain and gears in it,,on all the gm products, they have a tendency to wear out the chain and gears,,this throws the timing all out of whack on it,,and you cant set it with a light either,,it wont be no where near right,,all you can do is replace the chain and gears,,i own a repair shop,and i see a lot of them with the same problem especially if its got over 90-100 k on it,,the factory chain and gears seem to wear out pretty fast in those,,once you replace them,,you,ll see a noticeable difference in the way it runs,and performs,,good luck with it,i hope this help,s.,,have a good x-mas.

Answer 2

look the gm tbi thorttle body injection is the simplest type of fuel management system there is if u have a strong gas smell and black smoke coming out of the exhaust its not restricted, not possible otherwise u would see little of anything restriction means to hold back. anyways ur timing is fine timing chains on newer gm's either work or break they havnt used the plastic coated gears since 87 so dodge man is wrong about ur gears. start with the O2 sensor check the map sensor check for a bad injector an injector could be stuck causing the motor to flood also check coolant temp sensor or CTS as if it is bad it can cause the engine to think that it has not warmed up to operating temp. also check for a stuck thermostat, see that the engine is actually warming up. beyond this thats it but those other three guys dont know what they are talking about especially dodge man, he needs to stick to dodge junk

Answer 3

I think you should check for restricted exhaust. You can do it pretty easily with a vacuum gauge or rent an exhaust pressure kit and test it at the O2 sensor bung.
If all is well there, check for Diagnostic Trouble Codes for signs of any sensor or monitor out of range.
Go here------->

http://autorepair.about.com/library/ts/obd-i/bl-dtcs-95.htm

...for a discussion of the procedure for retrieving the codes. It is easy and only requires a paperclip.

Good Luck and Merry Christmas

Answer 4

If it has been running rich, strong exhaust smell and probably some black smoke, it will burn up your cat. conv. and thus restrict your exhaust. Check out what dodge man says also.