So I am only getting about 13-14mpg with mods in sig that was with mostly highway driving at 60-65. New fuel filter, air filter, fresh oil change. Has 4.10 gears cali truck. Also the truck will start different almost every time you start it. If the truck hasn't been started for a while you will turn the key and almost always it will crank for a second and start perfect. If i'm turning the truck off on and on repeatably it'll crank for about 2-3 seconds and start kinda weird but idle fine. And then other times i'll start it and it'll crank for the 2-3 seconds and then when it starts it pops and then runs fine. I don't know if there is something wrong making the poor starting and poor mileage. Or if i have two different problems. I'm thinking IPR o rings for the starting? Thanks

 

well the poor fuel milage is probably from your stock injectors, since you have the cali model you have the split shot. single shot injectors will give you better fuel milage. but since you live in cali there's not too much you can do without producing high emmisions. cause i got a 94.5 and I'm running it stock right now and i'm getting 17mpg but its got the single shot injectors. but with the emmision laws it's hard to get better mpg. they contractic themselves. less emmisions=less fuel milage. also have the 4.10 gears since its low geared your not going to get as good too. the starting problem I'm not too forsure with that

 

Thanks. Where i'm at there are no emmisions laws. Truck never gets inspected. So i can do whatever i want really. The truck just seems like it used to better on fuel. Idk might just be me

 

haha good then ya if you want to upgrade to single shot injectors and you'll get better fuel milage and more power.

 

Yeah maybe in the future i'll get some stage ones. Right now i'm saving money for school. I still think i should be getting better fuel mileage than that, it seems like it keeps getting worse

 

Lets compare apples to apples here rather then apples to peanuts...

Your 94.5 has AA or AO injectors, which while being single shots also only flow about 90cc per 1000 shots...

His 97 has AB injectors which flow 120-130cc per 1000 shots.

His truck will also product about 30 more hp then yours on the dyno.

Swapping to single shots can lead to better MPG, if your going from a 140cc split shot to a 160cc single shot, but I would not count on it.

Need to get the truck on a scanner, could be many different things, Low HPO, Injector O rings, High Pressure Oil pump... Could be as simple as a bad fuel filter.

 

Could be anything... but you should be doing better than that... I consistently get 18-19 mpg's mostly highway with 4.10's...

 

Ughhh i just need to find someone with a good scanner. Around here that can be hard to find without getting screwed. A few months back i took the truck in for a re call at the stealership and asked the guy if he could scan it for me. He said there were no codes but who knows he could be blowing smoke up my ***.

And what should i be looking for when i scan it? Just codes? Or %'s

 

very true with my 94.5 with those injectors but my old man does have a 97 dulley and it gets round the same milage I do. but your right it could be a variety of things. and with the scanning most of the time if you take it too a dealer they scan for codes i think they don't look at how the truck is running and what it's doing. at my school i scanned my old man's 97 and then also looked at what it's doing but it depends what kind of scan tool they are using. but most of the time if the check engine light hasn't come on there probably arn't any codes

 

Not correct. My SES light is not on, and I know for fact there will be 6 codes stored, just from the items I have deleted.

Your dad's 97 may very well have AA's in it as well as yours. Only the CA models came with AB's in the 97 MY.