The motor is a 12.5:1 B20B, I'm running a stock ECU, stock injectors for the time being. It was pinging under load with Fuel pressure at 60+psi even with 100 octane fuel. After checking the stock heat range (5) plugs, I decided on going with 1 step colder. Helped a little but pinging was still there. Ignition timing has little effect, running almost fully retarded.

A trick i read on another board suggested disconnecting the MAP sensor, which actually is doing the job for now. The ECU is stumbling the ignition timing at 800-1500 rpm but after that the car is running rich and a lot better than before, no detonation, plugs look rich.

I am wondering if anyone has got any suggestions or comments as to if this is normal for the engine to be running so lean even with stock cams. Fuel pressure seems to have no effect. I will be connecting my EGT shortly to read cyl #3. Until the break in is over, I'd like to have this setup running moderately well before putting in the hondata, 63mm TB, 450cc injectors, and the crane camshafts.

On another note, I am in contact with someone who can burn a chip with stock maps for 450cc injectors. If I'd like, he could add lets say 5% or 10% more fuel to accomodate the 200cc difference between motors (B18A1 vs B20B). If you had to blindly burn an ECU for this application for the break in, how much fuel would you recommend adding over the stock program?

 

lean due to timing, stock ecu and more fuel neds, and higher octane. get an AFC...

 

Do you have adj. cam gears?

 

some 310-340cc injectors and a VAFC will rock your world

mike

 

I've got adjustable cam gears, due to the head and block being resurfaced, I am using them even with the stock cams just to zero the timing of the motor completely.

I have some 450cc DSM injectors ready to go in after it is broken in, at which time it will be tuned with a Hondata.

My timing is almost fully retarded. EGT readings with the MAP sensor disconnected (no pinging) go as a high as only a hair over 1200F. Right now, without the MAP, I am able to hit 1/2 throttle on 94 up to 4000rpm without pinging on 94 with EGT as mentioned above.

My question for the time being is how to be able to get the computer to dump the same amount of fuel as it is now while having the MAP sensor connected.

BTW: The motor feels absolutely great

 

sounds like a nice setup.

i would higly recommend a B20 ECU program allong with 310-370cc injectors.

the higher compression is causing you to run really hot/lean. the B18 ECU wont give enough fuel to compensate for the extra CR.

the 84mm+ bore and high CR need a **** load of fuel.........as the experts.....they will tell you the same.

 

I would be very careful with that motor running lean. You don't want to "break" it in, if you know what I'm saying. Get the fueling issues more under control before you drive it much, or your motor will be very mad at you. With the MAP sensor disconnected, you are running very rich and run the risk of "washing down" the cylinder walls with too much fuel. Obviously, lean detonation is just as bad or worse.

 

non-vtec: does the b20 ECU actually differ from a stock B18A ECU? I was under the assumption that they shared even the same fuel maps. I have a feeling I am gonna need a bigger fuel pump with the 450cc injectors too.

b19coupe: Currently the motor is not running lean. I am monitoring that by EGT readings on cyl #3, and spark plug coloration. I agree about making sure the motor is running really well but I really don't think its running rich to the point where it is going to hurt anything. EGT temperatures are actually quite ideal, so this setup seems like its doing the job for the time being.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by non-VTEC &raquo;</TD></TR><TR><TD CLASS="quote">sounds like a nice setup.

i would higly recommend a B20 ECU program allong with 310-370cc injectors.

the higher compression is causing you to run really hot/lean. the B18 ECU wont give enough fuel to compensate for the extra CR.

the 84mm+ bore and high CR need a **** load of fuel.........as the experts.....they will tell you the same.
</TD></TR></TABLE>
exhaust gases are the hottest at stoich AF ratio. the farther away from stoich in either direction, lean or rich, the cooler the temps are going to be.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by teg92 &raquo;</TD></TR><TR><TD CLASS="quote">non-vtec: does the b20 ECU actually differ from a stock B18A ECU? I was under the assumption that they shared even the same fuel maps. I have a feeling I am gonna need a bigger fuel pump with the 450cc injectors too.

b19coupe: Currently the motor is not running lean. I am monitoring that by EGT readings on cyl #3, and spark plug coloration. I agree about making sure the motor is running really well but I really don't think its running rich to the point where it is going to hurt anything. EGT temperatures are actually quite ideal, so this setup seems like its doing the job for the time being.</TD></TR></TABLE>
you should probly get a 255lph walbro pump...too

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybridvteceg &raquo;</TD></TR><TR><TD CLASS="quote">
exhaust gases are the hottest at stoich AF ratio. the farther away from stoich in either direction, lean or rich, the cooler the temps are going to be.</TD></TR></TABLE>

To my understanding 99% of the time lean will result in higher temperatures. Larry (TOO) says not to exceed 1300F and right around there should be the desired EGT temps.

 

ya lean usually runs hot...

you should definately get the fuel pump... i'd go with the bosch unit endyne sells ... I'm sure a walbro will be fine though.

 

lemme try to find what i read that made me think stoich was hottest.. i think it was a post, and if it was i wont be able to find it...