Why does it take my car longer to start when I swap my P2P ECU for a chipped P28? It has to crank about 3x as long before firing up.

The chip has a good tune (14.7 afr / 16* timing at idle). I don't get what the deal is.

 

cranking settings coul be off..

 

Cranking settings? What do you mean?

 

Not sure if this helps any, never look much into it, but my friends car had a hard time starting and he did a clutch job, and we noticed the flywheel had some tooth missing, and a little worn on the edges of the teeth.

Just something to look into if all else fails

 

If I unplug my P28 and plug my factory P2P back in, it starts instantly. When I put the P28 back on, it cranks for like 2 full seconds before starting.

It's definitely something to do with the ECU.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Legion &raquo;</TD></TR><TR><TD CLASS="quote">Cranking settings? What do you mean?</TD></TR></TABLE>

The fuel/timing compensations used during cranking. What was it tuned with? If Crome, then the P30 compensations are probably still in place. That, or too much fuel was taken out of row #1.

 

^^^ sounds like it could be: Crome / Fuel Tools / Fuel Multiplier / Advanced / Individual fuel correction / Cranking fuel amount maybe incorrect. If your not using Crome you could check with your tuner to see what the cranking fuel setup is.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jim Truett &raquo;</TD></TR><TR><TD CLASS="quote">That, or too much fuel was taken out of row #1.</TD></TR></TABLE>


Lol, you may be onto something... The #1 fuel column is down to almost nothing. I figured I'd never be in that column!

I'll go add back to it and see what happens.

 

Y8's base timing is not 16* but 12*. Could also be an issue.

 

Damn. My maps show 16* at idle. I adjusted the dizzy with a timing light so it fires on the middle hash mark. That's 12*? Does anyone have any y8 timing maps I can look at?

 

Bump for more answers...

I'm using Uberdata still. The timing is spot on. I've toyed with the fuel values in the 1st column, but it doesn't seem to do anything. Still hard to start.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Legion &raquo;</TD></TR><TR><TD CLASS="quote"> I've toyed with the fuel values in the 1st column, but it doesn't seem to do anything. </TD></TR></TABLE>

1st row, not column.

 

I see that you said that your map is set @ 16. What map, fuel or ignition?

What does your fuel map look like.
Example:
A1 - 500 RPM x 114mbar (26.48psi) = 10 • A2 500 RPM x 288mbar (21.35psi) = 92
B1 - 602 RPM x 114mbar (26.48psi) = 10 • B2 602 RPM x 288mbar (21.35psi) = 92
C1 - 1000 RPM x 114mbar (26.48psi)= 12 • C2 1000 RPM x 288mbar (21.35psi) = 103
D1 - 1250 RPM x 114mbar (26.48psi)= 17 • D2 1250 RPM x 288mbar (21.35psi) = 108

 

Here's the low fuel map. I made a mistake earlier, timing is set to 12*, not 16. It's a y8 motor.

The first column values don't seem to affect anything. I guess it doesn't enter that vac column during cranking. I don't want to mess with the second vac column either, because it idles at 15:1, just where I want it.

 

The first cel is not be where you need to be adjusting. Could be A8 or A9 that need to be adjusted. That all depends on what the barometric or intake manifold pressure is being read at when you first start the engine. is it 114, doubt it, probably more like 1035 or maybe somewhere in between????

Don't play with the columns and rows on the left that is your IM at max vacuum throttle closed. Your looking to adjust the low RPM low vacuum cells. ie 500 RPM x 1035mbar. FYI I tend to adjust 4-6 adjoining cells at a time and then fine tune down to 1 or 2 if possible

My fuel map for my car reads 478 @ Cell A10 (500RPM x 1035mbar) and the number gets progressively smaller from there.

I am not familiar with Uber does it have any sort of fuel tools?


Modified by GhostAccord at 5:44 PM 1/29/2008