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-   -   Power FC Misfire Or Detonation? Spit an apex seal on poorly tuned row! (https://www.rx7club.com/power-fc-forum-47/misfire-detonation-spit-apex-seal-poorly-tuned-row-431054/)

Lynn Bordes 06-05-05 01:47 PM

Misfire Or Detonation? Spit an apex seal on poorly tuned row!
 
I don't know if I am too lean, too far advanved or don't have enough amplified ignition (stock ignition at the time).
I was trying to run only mechanically limited 10 psi. My wastegate spring jammed and it went to 16.6psi. This resulted in it spitting an apex seal.
The LM-1 showed lean.... but it would with a misfire also. Do I seem too lean to you guys?

I'm running 550's and 1680's my recaled base map is:
row P 18 from N12 over toN20 -20.4,21.1,20.9,20.0,21.0,20.0,19.1,18.0,17.2
row P 19 from N12 over toN20 -23.8,24.6,24.9,24.9,23.9,22.9,21.8,20.5,19.6

For PFC Leading Map I'm running
row P 18 from N10 over toN20 -10,11,12,13,13,14,14,15,15,16,16
row P 19 from N10 over toN20 -8,10,11,12,12,13,13,14,14,15,15,

Thanks, Barry

cewrx7r1 06-05-05 11:48 PM

(1) You can not determine lean vs rich by looking at an injector map because the comparison engine would have to have the same total injector flow capacity, fuel pressure, and breathing capacity as yours to be valid. That is almost impossible to happen. Only recorded AFRs for the P rows listed is valid for analysis.

My current P18,N15 is 21.052 which is 11.2AFR. Yours is 20.0.
If your air flow, fuel pressure, and injector sizes were exactly the same as mine then your AFR would be lean at 11.8.

(2) You do not mention what type of porting your engine has which affects timing. Even with stock ports, I would say you have too much advance for N12-N15.

twokrx7 06-06-05 05:39 AM

Detonation can feel like severe misfire ...

Lynn Bordes 06-06-05 04:48 PM


Originally Posted by cewrx7r1
(1) You can not determine lean vs rich by looking at an injector map because the comparison engine would have to have the same total injector flow capacity, fuel pressure, and breathing capacity as yours to be valid. That is almost impossible to happen. Only recorded AFRs for the P rows listed is valid for analysis.

My current P18,N15 is 21.052 which is 11.2AFR. Yours is 20.0.
If your air flow, fuel pressure, and injector sizes were exactly the same as mine then your AFR would be lean at 11.8.

(2) You do not mention what type of porting your engine has which affects timing. Even with stock ports, I would say you have too much advance for N12-N15.

ITO street port.
Chuck, from Wargasm's Base Map Units discription, can't we compare Milliseconds of primary injector on-time if we both have 550's and running stock pressures? (Mark57 finally got it thru my thick head on the Base Map's units of measurements.)
Thanks to you and Kyle for the help, Barry

cewrx7r1 06-06-05 08:42 PM

After going GT35R and doing initial AFR tuning, I rewired my fuel pump. This was the only change made to the fuel or ignition systems since going single. I did this to increase the fuel pump performance which lowered my injector duty cycle at the higher revs.

Now my high rpm section of the injector base map has smaller values than when I ran 350RWHP with non-seq turbos, but my midrange values are larger.

If I compared my old 350RWHP map to my current and not knowing anything else,
I would correctly assume that the engine is making more power in the middle rpm range, and wrongly assume that above 6000 rpm I am making less power.

Baryy, I will e-mail you my current map.


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