36 I believe

hmm, you would think new injectors would have been part of the performance package you got.

Normally it'* safe to run the stock injectors with as low as a 3.0 pulley.
No one thought that they'd be maxed with a 3.2 pulley.

It may be the case, but I still have my doubts that your injectors are causing you to run lean. I know the duty cycle is showing they're maxed, but it just sounds odd that my 30# injectors will support 400hp, and you're maxed out. Are you running too rich?

Could a bad fuel pump or a dirty fuel filter be the cause?

We hooked up a gague to the fuel system today.... it was reading 40psi during idle, with a quick burst it went upto 60psi.
We replaced the fuel filter and it went up to 43psi during idle, with a quick burst it went upto 65psi.

I don't think its the injectors either. My dad went 12.78 and was running a 2.76 pulley on his stock injectors before they were maxed out. Usually you have to go under a 3.0 pulley at least before you have problems. 36lb. injectors can flow a lot of fuel.

You also have to remember that our engines are supercharged when you are thinking about the hp level that injectors max out at. While the engine might be making 400hp, it is probably using 80hp of that to turn the blower, so you are only seeing 320 of those ponies, but the engine is actually putting out more than that.



Shawn

The PCM will command the injectors to open longer (pulse width) to make up the fuel it needs to get the right AF mix. If your injectors are unable to keep up then 2 things can be wrong. The injectors themselves may just not be able to flow enough fuel or, your fuel pressure is low and so the PCM has them opening longer to compensate. You may want to get a fuel pressure gauge and check it at WOT to see pressure. It may be that you can get a new or better pump or regulator to up the pressure and you would see your injectors calm down.

Hmmm...

No doubt the fuel system bears further srcutiny. Good move to change the filter though, but still there'* cause to think you have a bit of a fuel supply problem. I know the Grand Prixs have a fuel pump pump resistor and 2 pump relays (low & high speed), maybe the Bonneville is similar, I've seen plenty of GPs with pump related problems.

On the other hand, your O2 values versus IPW are interesting;

20.17 977
20.48 981
19.94 972
20.13 955
20.39 946
20.72 938
21.03 929
20.94 929
21.23 924
21.41 920

Initially your O2s are rich, starting at 977, yet the IPW is 20 which has shown to be tolerable. As time passes your O2 gets leaner, into the range it should be, yet the IPW is rising...meaning the fuel delivery system can't keep up.

Also, how are you getting the reading of 16 psi for the boost? There are 2 reasons to suspect this reading;

1) The MAP sensors are limited to 2 bar which means they shouldn't read that high. Try swapping around the MAP connectors, there are 2 of them mounted side by side, one is used by the PCM and the other is used by the guage.
2) The PCM will become confused at boost readings over 2 bar.

Let us know...

Cheers,

Yes the Bonneville has the 2 speed settings for the fuel pump too...... it'* the next thing on the list to replace.

Mechanical gauges....

What do you mean by "bar" and "2 bar"?
.... and where are the MAP sensors again? hehe

bar is a measure of atmospheric pressure.
Dictonary.com says:
"A unit of pressure equal to one million (10^6) dynes per square centimeter."

That help?