I'm lost

Ok, I made a thread asking for your alls mpg on lt1's a few days ago. Well, mine isn't up to shape compared to what you said. I'm getting about 11 or 12 mpg.:frown: I'm hoping if I give you guys the symptoms I'll be a little more prepared when I go to the mechanic so he doesn't "fix" things that aren't broken. Anyway, here's what I've got:

It may be missing, my dad says it sounds like it and has uneven exhaust rumble.
It smells like it's leaking fuel, but it isn't from under the car cause I had it checked when they fixed the exhaust leak. Maybe coming out the exhaust.
No codes or SES light.

I'm hoping for something simple, but I figure its Optispark since I hear they break pretty often. I can't drive like this though.

Optispark? could be...
Start with a tune up and check your timing.

:iagree:

Always replace the basics right after you get a 'new' car home. You'll learn alot on how it's lived life up til you.

We pulled some of the plugs that we could get to easily, and they looked good. I know that doesn't mean much cause the rest of them we didn't get, but the ones we pulled looked really good.

Yeah well that's the thing, the one's you pulled. I've seen cars where all the plugs that could be reached looked good, and after wrestling my way to the others, they looked like they'd never been changed, so just saying.

Plugged Cat??

I'm throwing something out there...

That slipping trans will also take away from mileage. But like was said, its always best to replace the basic stuff when you get a new car. You just dont know its history. If someone was lazy and only replaced some of the plugs (the ones that you can get to easily) and left the others then you could have a problem.

heck yeah it will...and also what was said, replace all the basics. i myself replace the belts, spark plugs, wires, battery, water pump, alt, flush all the fluids, get better exhaust, and a cold air intake. thats the first thing i do. but thats me

I'm going for a tune up on Friday probably. I'm just hoping to keep a little money in the bank for bills though. How much should it cost for a tune up?

On my last Z, I got a tune-up and it cost me around $1000 or so, I can't recall though. Most of that is in labor. That opti is the biggest pain in the ass I have ever seen, and I don't know what GM was thinking putting it under the water pump like that. So, be prepared for shelling out some extra dough. That is the one of the major downsides of the mighty LT1.

change your fuel filter too, thats a big player when it comes to gas mileage..

Do a tune up, Old plugs and wires with a partial clogged fuel filter will kill gas mileage. Might also want to swap cap and rotor. Get off of ebay though cause everywhere else they are way way way over priced. Could also have a bad injector or two. If the tranny is slipping, that as stated will severly hurt gas mileage as your wasting gas by accelerating but basically going no where. Good luck

heck yeah it will...and also what was said, replace all the basics. i myself replace the belts, spark plugs, wires, battery, water pump, alt, flush all the fluids, get better exhaust, and a cold air intake. thats the first thing i do. but thats me

Soooo... Basically the finrst thing you do is pull the engine and completely rebuild it??? :cwm27: :rofl: (jkg)

Ok, I took it to the dealership today and had them hook it up to their computers. They took about an hour and looked everything over. Anyway, it came back with having 0 volts in the MAP sensor. So they told me that was the problem. They said it was either a wire messed up (the mechanic said it's probably not that since he moved the wires around a lot and that should have given it a kick or somethign even for a second) or the sensor was messed up. So it would costs me two hours of electrical work from them (100+ dollars) or I could replace the sensor and see how that goes.

So I went the sensor route. I bought one for 32 dollars at advance and replaced it. The old one had some rubber seal or something around the sensor, but the new one didn't come with one so I just put it in the engine. So the car has a lot better throttle response (it use to go to 2500 rpm before it would really pick up, now it picks up as soon as you touch the gas), but it's still sucking gas. So is there some way I can just check the wires coming to the MAP sensor and check their voltage?

They told me the air temp sensor was in the same situation, but it probably wasn't working because the MAP sensor wasn't working. Any ideas on that?