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Major unbeatable KR

Sabrewings

Sabrewings

New member
I think I'm down to having something seriously wrong with the engine, though it runs fine otherwise. It isn't a tuning issue like I originally thought, so it's time to wipe the slate clean and get some fresh opinions. I'll lay out the facts.

1.) The issue is present no matter what tune I put on the car, stock or not.
2.) KR in excess of 3* when under light acceleration.
3.) Is worse with the TCC locked than unlocked (higher MAP levels, I guess).
4.) Is worse the hotter out it is. No knock when the engine is cold and fresh.
5.) About the same with the MAF plugged or unplugged. There is maybe a drop with it unplugged, but not very substantial.
6.) Changed plugs, wires, O2 sensor.
7.) Engine appears to run great by listening to it. No misfires. I wouldn't even know there was a problem without a tuner or scan gauge other than the lack of power from so much KR.
8.) As soon as it hits PE knock jumps sharply to about 8*. O2s in the 880-890 range.
9.) I'm already running 93.

It was so bad today (hot out) that the PCM went to the BFS table. I was cruising (with occasional knock) at 60MPH with 26* spark advance . I only had about 8-10* of spark going up steep bridge. :(

This has been driving me nuts for over a month. I'm hoping I can get some fresh ideas going here. The only possible lead I have is a fuel smell near the #2 fuel injector. I noticed that while leaning over the alternator doing my plugs.

Any ideas?? :th_shakinghead2:
 
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While brainstorming... could this be a bad/clogged injector? Or leaky injector o-ring? If one cylinder was being starved of fuel as demand went up then the O2s would still look about right (I think). What strikes me as weird is the KR (90 % of the time) seems to start when the IPWs hit the 7.5-8.0ms range.

Just throwing ideas out there. I'm going to pull the fuel rail and visually inspect what I can this weekend.
 
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Well if it were a clogged injector it seems like it would do it all the time. wether it was cold or hot. I think we need to concentrate on that fact that it doesent do it when cold but when hot it does. maybe make a list of the tables that are altered in the pcm according to ect. just a suggestion.maybe a sensor or something will come to mind when we do this.
 
Ill answer for him. Yes . I think we figured out that it isnt tune related.
 
its N/A 3 degrees of KR isnt going to hurt anything, there is no forced induction so theres nothing to blow up. use a wide band my car had a A/F of 15.1 for about a year because "i had a tuner i knew how to tune". we put the car on a wide band and a dyno and it made 100WHP. what a kick in the balls buying a powertuner was. N/A my car loved a 12.8 A/F ratio, made the most power 200WHP and felt the greatest. best bet is to find a reputable dyno shop, with a mustang dyno so you get real world numbers, and pay the 500$ to have them tune the optimally. driving the car on the street and trying to tune is not the right way to do things when you can strap it down on the rollers and go to town. im not trying to sound like a dick ive been there done that and a custom tune done by a great tuner was the best money i ever spent

on the second note, if you smell fuel its most likely the injector o-ring could be torn, thus the fuel smell and a tiny vacuum leak. happened to me when I installed the HV3 and didn't grease the o-rings for the injectors
 


I guess we've pretty much exhausted ever other tune and fuel possibility. You might be going in the right direction in thinking that it may be something in the engine. Could be valve rattle or something maybe?

Personally, I'm not a fan of dyno tuning....I'm all about streetability, but different strokes for different folks.
 
Kr is in excess of 3*, His max he is getting is around 8*. And I can tell you now, he wont be satisfied with having even 3* and neither would I. 3* of KR running N/A is the same as 3* running S/C. I'ts still 3*. Yes it is much easier to get kr running S/C but 3* will do the same amount of damage on both motors weather there supercharged or N/A
 
I'm pretty sure it isn't a tuning issue. I'm also maybe leaning towards a slight vacuum leak. It would make sense because I didn't lube the lower injector o-rings or replace them when I did my gaskets. I'm 99.9999% sure my gaskets are sealed perfectly.

Vacuum lines look good. I have a set of six o-rings and I think I'll replace all the lowers this weekend if I get a chance. That fuel smell last weekend in the #2/#4 area bothers me, but there's no visible leak that I can find.
 
thats probably the problem, no luve for the orings and theres your leak. use vasoline, the jelly not the song by STP:th_thumbsup-wink:
 
QwikGT said:
the jelly not the song by STP:th_thumbsup-wink:
Click to expand...

I can't just sing it? :th_laugh-lol2:

Actually I'm going to use some clean motor oil. I keep what's left of the last bottle when I do oil changes for just this type of thing. Besides, that's what GM's service manual says to do. I'll post up what happens Saturday.

Until then, anyone with some fresh insight please let me know. :th_peaceout:
 


o ring grease is the best because it swells the orings so they seal better, ive always used vasoline so just throwing it out there
 
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