Recently, I have been told that the owner of a '97 GSX has never put in gas with an octane higher than 87 even though the car calls for 91+. The car has been fouling out plugs, sputtering, and sometimes stalling when at a red light, pulling into a parking space, etc.. Would the differences in fuel grade do this to the car? And if so, what problem am I looking at to trying to fix it? Such as, what part might need to be replaced? I'm thinking the oxygen sensor, but I may be wrong. Any other suggestions would be greatly appreciated.

TIA

Im still new to eclipses, so dont kill me if im wrong

But i think he's lucky its still going, with a turbo application or any other major FI and nitrous, Higher octane fuel is required to combat detonation. I'd pull apart the engine and take a look at the pistons, he's probably burnt up his rings if not the pistons themselves, and i wouldnt be suprised if you find a few melted exhaust valves.

It's possible that the problems you are describing are related to the fuel, but it's not necessarily the case. My dad runs low octane on his gst too often - but if you don't boost when you have low octane then you won't have the ill effects of detonation. the easy thing for you to do is put in higher octane and see if there is a change.


after that, check your spark plug wires, and change the fuel filter that's a common source of your problems

2gnt: '99 RS-T, killed by a toyota, pending rebuild...
Daily: Volt
Daily #2: '99 EVG ebike- STOLEN by PEDRO

Oh pulling the engine is the absolute last thing on my mind. We changed plugs and wires a week ago, and that seemed to fix the problem until the next day, then the symptoms returned. I then checked the plugs again, and they seemed to be on their way out. The GSX is completely stock and is running stock boost, so detonation wasn't a concern. After the 87 octane ran out, we put 91 in and noticed a slight difference, but we still have the symptoms.

I bought a new fuel filter, o2 sensor, and new plugs and hopefully will be installing those today if all goes well. I know that fuel filter is going to be a major pita. Hopefully the o2 sensor won't be as bad.

Are there any write-ups for removing/installing the o2 sensor and fuel filters? I know where they are, and basically know how to do it, but maybe other people have found easier ways of removing and installing these parts.

TIA

Are the plugs burnt or black?

i'd have to say 50/50 on the plugs

fuel pump, umm what year is it.. i think it was 96 or 97 that they put it under the rear tire...

95 i know its on the firewall pass side.
you need a 2 open end 19mm i believe. to crack the nuts, its pretty easy just have to look at it and go to wokr.. make sure you use the new washers

o2 sensor, just a 23mm or 15/16 open end unless you have a 02 socket one with a slit in it

you will unplug the o2 sensor if you bought one with a plug.. just plug it in and screw the o2 into teh bung..

pretty simple
umm igniton and fuel are the 2 things to check.. so keep looking
hows the battery.. a weak batter could cause some of these issues

if you are dentonatin when you are getting on it the car will sputter and make all kinds of bad noises but will only happen in the top end..

on a boosted application id run 91 or higher

my stock na gsr had to get premium now im boosted though

the higher octane the cleaner the gas is.. not good to run super high ocatne gas all the time but 93 is fine

it does exactly what dude said, lowers the chance of det.

I love dino and 2gnt. ####ers (my word) bliz stole it but i let him borrow it

Ok, no such luck replacing the oxygen sensor. Stupid thing will not budge and the nut was starting to round out.

I drove the car before working on it and got it to stall 4 times within 5 minutes. I came back, put in new spark plugs, drove it around again and couldn't get it to stall. The old plugs I took out were not fouled, they looked like regular spark plugs in any car.

What is going on?!?