So i put the 2.55 pulley on down at boostys this weekend.

First off i did scan before the pulley, everything looked fine, no KR at all.

It was feeling good but i could feel something at like 70%+ throttle so i did not get on it much.
Today i scanned for KR, O2, and Tested the Fuel pressure while driving.
Out side Temp 75-80*F



In First gear i get about 1-2 KR at 70+% throttle.
in Second gear i get 3-4 KR at 70+% ( More KR the higher throttle, Saw 6 once)
in third gear i saw 2-3 KR sometimes.

Fuel pressure at like 10% throttle was like 38ish, Idol about 35-36. When i nailed it it jumped right up to 46-48 and stayed there even when i started to get KR.


Now for the O2.

First gear at 70%+ throttle i was seeing 885-895 (once i saw 910 when i frst started driving)
Second Gear at 70%+ throttle i saw 860-875. Mostly 870-875 and it did not Drop when the KR started.


So the question is, I know my fuel pressure at the fuel like is good, But how are my O2 Readings?
Normal? Low? Right on?



Things i have done....
-TR55 Plugs gaped to 60
-K&N Filter on Rice pipe
-2.55 pulley


Other things old or need to be done...
-wires are newish looking and in good shape but are cheap ones.
-PCV has not been done yet
-Fuel filter, but fuel pressure is fine.
-SCer Coupler, Have it waiting to go in.
-Belts, starting to crack.

If I'm not mistaken, I had to gap my Autolite 104s to .055 when I dropped a pulley size. That was on my '94.

so you're running one heat range colder plugs at 0.60, I'd reccomend 0.55

0.52 for 2 heat range colder, just what I've found works best in my experience.

Are you saying you checked the fuel pressure under load (remote line) ?\

My fuel pressure was fine at idle but was dying at the top end. a new fuel pump fixed nearly all of my KR issues.

Re-gap your plugs.

Wires won't generally cause KR like that. 1-2 degrees is acceptable on pump gas in those temps, and tells you that you've pushed as far as you can.

How old is the O2?

I suggest completing the standard tune-up items and regapping your plugs for starters. After that, we'll be chasing small vacuum leaks and exhaust leaks. It wouldn't hurt to clean your TB and MAF sensor if that hasn't been done yet, and replacing your PCV valve.

Thanks guys, You make me feel better now

O2 looks to be factory, i was planning on replacing it soon anyway just cuz its old.

im going to re-gap those tonight if i get the time.


Hans- Yup i ran a high pressure line thats like 7 feet long. Works great for testing while driving never leaks

Yup, Re Gapping the plugs made all the difference

It was 87*F out side and i waited for the engine temp to hit 180* and then started the testing.

First gear. No KR. saw Maybe a 1 once and thats it.
Second Gear at like 90%+ throttle i saw 1-2 and 3 once. But like wren says with no race fuel and a Hot day like today thats ok.
I just wont keep it floored for long at floored all the way when i know its this hot out.

Tonight im going to do more testing, it should get down to the mid 60'* so that should be fun

IMO 1-2 degrees is still knock. All knock is bad, if you don't tune your car to run 100% in the worst weather then you are tuning your car for fair weather only.

not to argue with you bill but...

Who'* right here? :?

i'll let you two figure that out and then i will start to look.

I dont want to replace $200 in parts and take off the Manifolds to check for cracks and do all sorts of other things to just find that im still getting 1-2 KR

1-2° is the acceptable 'rule of thumb' when pushing performance. You know you've pushed as far as you can.

If you get zero all the time, how do you know what you COULD have done? Think about it.

My personal target is 1-2° in 90+ degree temps, heatsoaked, and at WOT.

Do you think if it went down to like 50 or 52 Gap, would that help or hurt anything? :?