I bought the filter RC 5000 for off my TB and is there a possible way that that could be cause my car to run really rich? Ever since i instaled it i started getting 12 MPG 156 miles on a tank and before i had 188 miles on a tank and i didnt know what MPG i was getting then. But is there anyway that could be doing that? I was thinking about buying a AFPR and lowering fuel pressure but i thought that might be a bad idea since id prolly make it to lean. So any advice on this is greatly appreciated.

Thanks Nate.

 

Sounds like the car is in a poor state of tune. My 5.7L car gets 20+ on the highway, and 18-19 in the city. I average 250-260 miles between fil ups. Being a 305 car, I'd think you'd get the same gas mileage or more.

 

yea id thought id get better too but its not like im always on it and stuff i drive normally. Ima have my mechanic look it over and all that good stuff when i get my starter rebuilt. My uncle (certified mechanic) inspected my car and he said nothing was wrong hes prolly gonna say somin like its a camaro its suspose to run like that or something lol. I just replaced dist. cap and rotor and plugs too and i have MSD wires to put on it could wrong gapped plugs do this? Im so lost.

 

The filter will not do this.
Make absolutely positively sure that you have your wires on the correct plugs and that your plugs are gapped correctly.
You would also do well to get access to a datalogger to see what all your sensors and the ECM are doing.

 

I know this sounds noobish but whats a datalogger lol i think my bro has one for his old eclipse but he said it wouldnt work on my car i wonder where i could find one

oh and wouldnt it miss or not run correctly if my wires where on the wrong ones?

 

A datalogger plugs into your aldl and lets you see what the ECM is seeing.

I've made the mistake before of putting 2 wires on the wrong plugs. I noticed nothing different about it until I hit torque lock. That's when it started vibrating. I took it into the trans shop for diagnosis and they told me that it was a dead miss. I didn't believe that I couldn't feel or hear anything until torque lock. They told me that it was always there but that I didn't notice until that point was because I have a 9" torque converter. Less vibration dampening than a stock converter.
It's simple and free for you to trace your plug wires and verify 100% that they are all correct.
Sometimes it's the dumbest things.

 

When im dooing lets say 35 and i just barley have my foot on the gas it kinda sorta misses i think you could say that but thats the only time something feels wrong ill check the wires today after my car cools baack down

 

I had a similiar problem and after running seafoam through my car, I noticed I had a vaccum leak where the AFPR connects to the plenum. It was an easy and cheap fix.

 

a vacum leak can cause the car to run rich??? i never even thought to check those lol ill look at that one today to. thanks for all the seguestons.

 

Check the vaccum lines under the plenum, they are plastic and will get brittle with age. It still seems like the car could use a good tune up. (plugs, wires, cap & rotor, fuel filter, 02 sensor) How many miles are on the car? What's the condition of the catalytic converter? Just some odds and ends to look at.

You might want to search eBay for a used Auto Xray so you can scan the car for codes and look at real time data.

 

I just replaced the cap rotor an plugs and have wires that arent on yet. I didnt change fuel filter or 02 sensor. But if the 02 sensor was bad wouldnt it throw a code? and when my uncle did my exhaust he took the cat off. There are 63xxx on the car and it was sitting for 2 yrs before i bought it 1 was in a garage other 1 was outside ladys house covered up.

 

The 02's won't always throw a code, with a scan tool like an Auto XRay, you might possibly see the 02 being a bit lazy Mv wise. Usually crappy gas milage and a bad 02 go hand in hand if you've covered all the other bases.

 

im thinking its the plugs because it misses at any speed if im lightly on the throttle. But ill try an look into one of those auto x rays

 

it is indeed a good idea to start somewhere when dianosising your vehicle...
of course if your not a mechanic then what i'm about to say will throw you off and if your uncle's a mechanic he should perform some of the following tests that i have listed...for i too am in the hunt for increasing gas mileage on my vehicle..

1st the basics....check your timing, check your engine vacuum and check for vacuum leaks, check fuel pressure and compare it to specs...check the gaps of the plug and wire routing...

Now a bit with the technical...
1) with a scan tool you wanna look at your basic information IE: O2 sensor signal making sure it's a continuous wave form pattern..even though it's not all that important you wanna look at 02 sensor cross counts...Reading this gives a good idea what is coming out of the exhaust stream. O2 sensor readings is a waveform patter that fluxuates up and down. 450mv is a typical and normal reading on average. However you don't want it reading too low or to high. Having that said this can predetermine what's happening to your fuel milage.

2) again with a scan too, reading what the Block Learn Memory (integrator) is at Idle and during at cruise is important. While running in "close loop" we want to be as close 128 as possible...this here is important because it'll tell you weather your car is running lean or rich (just like the o2 sensor only this tells you what the car is doing over in the long term)...The integrator is telling you what the computer is trying to do compensate for what is lost, therefore if it's seeing that it's running too lean (i believe if it reads lower then 128) then it's gonna try to rich out the system by extending the injector pulse width time. If it's reading too rich then it's gonna try to shorten the injector pulse width on time...visa versa (this also can affect drivability and fuel performance)

3)You wanna check timing as well. This is pretty much your baseline when it comes to spark firing to each cylinder. If it's too advance then your gonna end up dealing with pre-ignition. If it's too retarded then your gonna be dealing with a waste spark and therefore unburned fuel will be passing out and into the exhaust stream, taranishing your cat converter. This is not what you want!

4)again with a scan tool, it's always a good idea to see what your coolant temp sensor is doing. You always want to make sure that when the thermostat opens up and that the computer will see it and activates itself to go into close loop. Note: It is never a good idea to install anything below a 180 stat in a computer control vehicle that's STOCK...If you do, the vehicle will remain in "open loop" (cold) continously, you can expect the computer to waste fuel in a hurry. The reason the ECM would do this is because it's trying to warm up the engine to a point where it can see a certain temp to be reach and therefore reach close loop...

5)With a DSO (digital storage oscilloscope) several features in these tools can come in handy: it can check out iginition spark burn time, engine power balance, injector drive time, individual cylinder effiency,..just to name a few tests...
this tool can also find out for possible cylinder misfires! I won't explain all this because it takes too much time to discuss and you may have to do a search on this...

6) another good tool to have is a 5 gas analyser...For those vehicles with cats, it can help read out how much Hydrocarbons, Nox, CO2, CO, and O2 gases that are coming out of the tailpipe...again discussing this topic get heavy and a search would be needed to discuss how this can help optimize fuel effiency and engine performance...

7) other tests that can be performed, would be a basic compression test and cylinder leak down test...of course your gonna need the equipment to do these procedures..

All that is listed here is not in order, plus for every application it would differ depending on what kinda engine your running, what modifications that have been done, and what kinda results you are looking for...so some of these test may not even apply...hope this helps a lil....

 

Ight ill have to talk to him about doing some of that cause i dotn have acces to any tools like that. Im pretty sure my plugs are gapped wrong tho ive been driving it for about a month like this do you think the plugs will be bad and ill need new? I bet their all fouled up cause of it runnning so rich.

 

I read somewhere on here about cars that sit for a while sometimes have problems with the injectors . Could a small tear in the fuel pressure regulator diaphram cause it to run rich ?