Shooting for 35 mpg

[3gd16]

Originally Posted by tortillasoup

So why don't you just re-hookup your o2 sensor then? Other thing you should do is reset the computer by disconnecting the battery for like 15 minutes so the computer can re-learn some of its functions. Also, you shouldn't have to remove the catalytic converter from the car for it to get good fuel economy. If your car has two o2 sensors, and the cat is removed, that too can affect fuel economy since the car uses the second o2 sensor for fine-tuning the fuel trims. When you're checking the grounds, be sure to measure from the point of interest to the battery negative terminal. To eliminate the most obvious point, be sure to clean up the battery ground strap, its nuts, bolts, washers, eyelits, etc, don't scrape any paint off but make sure the holes it bolts into are free of dirt or rust. From there you can get a better idea with the multimeter of how good or bad your ground resistance is. 1 ohm of resistance is 1 ohm too many!

I should mention that you should get your car back to stock as best as you can. After re-reading some of your posts, I realize that you have too many things on the car that aren't stock like the wrong distributor and whatnot. You should never have to advance the distributor too far in any one direction otherwise it potentially prevents the computer from doing its job of adjusting ignition timing properly. If you could get everything in your car working 100% like stock, 32mpg should be within range. Have you tried replacing your PCV valve? That's an easy fix on this car and its replacement can boost fuel economy by about 15% if it's clogged. Or how about clean the throttle body/idle control valve? Is your car idling at stock RPM with stock ignition timing degrees? I bet it isn't! All the check engine codes have to be gone if you expect to have your car perform optimally.

I will try to reconnect the o2 sensor when i install the shocks. As for the cat converter i didn't remove it was never there when i got it and i only use one o2 sensor this car is obd1 and reads from the o2 before the cat converter. The ignition will need to check it out to see how far it is in timing, they are the same cause it was a little more advanced with the stock ignition.

The car has new pcv valve with gasket and even a new intake manifold gasket was changed on the car, it is all stock just the ignition changed and a cold air intake. I did a lot of maintenance to the car timing belt and all those components, spark plugs, spark plug wires, rotor, cap, the computer was repaired a year ago and the only code i get is from the o2 disconnected, fuel filter, motor oil and filter, auto tranny oil. Every nut and bolt is still stock on the car, the iacv was cleaned and the fitv was cleaned and adjusted for proper idle witch is at close to 1000 rpm i still have a/c and will keep it. Car has over 252,xxx miles on the clock i don't know if the engine was rebuilt in any time but that is something that will come sooner or later to freshening her up no smoke no oil consumption no water leak or consumption.

[tortillasoup]

Just be sure to re-read my suggestions in my last post and make sure you don't skip over any. Also your idle is not suppose to be 1000rpm, you may need to get a digital tachometer and or have a technician adjust your idle speed + ignition timing back to stock. Your idle speed should be around 700RPM, and your ignition timing is BASED upon that correct idle speed. You will see this spec under your hood on a sticker. This is why it's so important to make sure everything works when stock and if you have everything hooked up and it's not working, then you should work on the car until everything is working.

[3gd16]

Thanks bro will work on that later today.

[3gd16]

Well i finished installing the shocks this morning, took her for a ride and ohh boy does she feel quiet now. Ran for like 30 minutos to see how the o2 was working and my RPM's are now down to 750 more or less, i have no clue how this could have an affect with the o2 sensor but it is running a little lean like i want it to be. I have to put the rear stocks and ball joints and install my EFIE back to adjust the mixture a litlle more leaner to see if i get more mpg or lose some.

[tortillasoup]

I have a friend who had a '91 Honda accord and he burned a hole in his piston because he drove too long with the EGR chamber clogged. I don't know if you have any check engine codes for the EGR lift, but if you have a code that occasionally comes up, it's because the chamber is clogged since the older accords do not have a way to measure EGR flow. There is a guide floating around that I can send you which shows the procedure for cleaning the EGR chamber which btw isn't that trivial since Honda didn't make a removable chamber until '94. (You have to port holes, clean the holes, then use a specific Honda plug for these holes)
Let me know.

[3gd16]

Originally Posted by tortillasoup

I have a friend who had a '91 Honda accord and he burned a hole in his piston because he drove too long with the EGR chamber clogged. I don't know if you have any check engine codes for the EGR lift, but if you have a code that occasionally comes up, it's because the chamber is clogged since the older accords do not have a way to measure EGR flow. There is a guide floating around that I can send you which shows the procedure for cleaning the EGR chamber which btw isn't that trivial since Honda didn't make a removable chamber until '94. (You have to port holes, clean the holes, then use a specific Honda plug for these holes)
Let me know.

The only code i am getting is from the o2 reading really crazy bought a new one yesterday from the honda dealer its a bosch sensor so it may be better then the NTK one it had on. I don't think the egr has anything to do with the piston melting mine has never been cleaned and i run a little lean and have no problems yet, but of course mines is a daily car automatic that take to work no more then 3000 rpm ever i baby this thing for ever. She has to last to 300,000 miles at least cause i don't want a new car need a house first. Thanks for your reply.

[tortillasoup]

The reason why running lean will burn a hole in the piston is because it makes the car run very hot even if the engine coolant is ok. Having a clogged EGR will cause the car to run hotter than designed and it's one of the things known to cause a burnt hole in a piston. As for your o2 sensors, maybe you should check your wiring running from the ECU to the o2 sensor and also check your grounds to make sure nothing is shorting out or damaged in any way. If you don't want to destroy your car, I would avoid running it lean unless it's for short distances like 15 miles or something.

[3gd16]

Originally Posted by tortillasoup

The reason why running lean will burn a hole in the piston is because it makes the car run very hot even if the engine coolant is ok. Having a clogged EGR will cause the car to run hotter than designed and it's one of the things known to cause a burnt hole in a piston. As for your o2 sensors, maybe you should check your wiring running from the ECU to the o2 sensor and also check your grounds to make sure nothing is shorting out or damaged in any way. If you don't want to destroy your car, I would avoid running it lean unless it's for short distances like 15 miles or something.

I checked the wiring harness to the ecu and it is ok as for the lean part it has to do with the o2 sensor i unplug it and it runs fine don't know if it is as rich with the sensor plugged but i bought a new one Thanks for your help i will see how the egr is after i plug in the new sensor.

[drmiller100]

burned hole in a piston is ignition timing or waaaaaaaay lean.

and waaaaaaaaaaaay lean is an O2 sensor. maybe a MAP sensor.

EGR won't burn a hole in a piston.

[tortillasoup]

A clogged EGR can affect the way the car runs since the engine computer is programmed with certain parameters in mind, causing it to run lean. O2 sensors usually fail showing lean which means the car will run rich. A clogged EGR will allow more fresh air than is designed and therefore letting the car run hotter. If you look up a generic list for reasons for a burnt hole in a piston, clogged EGR comes up as one of them.