What am i looking for in A-tap to check my
Injector Pulse Width (left and right side)?

thanks

 

Yes, use the Inj PW (banks 1 and 2). It will give you readings in milliseconds. Take that number and do the following formula to come up with the average injector duty cycle:

Inj PW x RPM/1200 = Inj DS

For example:
18.22 x 6400/1200 = 97.17% DS

 

I think the item to check in the list is 'Average BPW bank 1' or something similar.

 

at what point should i consider better injectors?

 

I think duty cycle over 90% is pushing it. Most try to get around 80%. Over 100% I'd say is the red zone. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

Yep, 80% is the value to shoot for. For short bursts (1/4 mile, etc.) up to 90-93% will still work - though if you are auto-x'ing, roadracing, silverstate, etc. then they would probably cause problems at that level.

Chris

 

so should i replace my injectors if its hitting 85% ?
1998 trans am

 

The 80% max duty cycle is what most vendors who make injectors use as a standard.
Having a bit larger injector does no harm and just means if the engine needs that during spiking you have reserve to meet what the PCM is commanding and injectors are not falling behind.

The Bosch SVO #30's are the same design as what is used in the LS1, are fairly cheap about $215 a set and function well. Mine have been used for over 1 year now and no failures even at long distance ORR racing.
They give you about 30% fuel increase so those running 10-15% too lean with a somewhat modded powertrain these will cover that problem and have reserve when highballing it on the track.

 

You should not run with 90% duty cycles if your injectors are the multitech II design.

Pre 99 cars had the multitech I design, good idea was to have the fuel pass through the injectors coil which kept the coils cool.
The problem was with the crap in todays gas or from additives they broke down the coil windings.

Multitech II to solve that problem now has the coil out of the fuel stream and thus get hotter much quicker and thus you do not want them running with larger pulse widths for any real timeframe.
The design though allows the injector to react faster in open/close and thus voltage offest changes have no positives to performance.

The longer the pulse width is the more current load on injectors, coils and PCM.

The covers over coils, injectors, fuel rails on C5 might look pretty but I do not use them for it causes more heat built up to all those functions and does not allow any airflow to put heat away.
Hot fuel sitting in injectors after engine is shut down will increase deposit builtup in injectors.

 

if i upgrade to 30 lb. ford injectors, do i need the PCM to get edited?

thanx!

FYI...my pulse width:
18.49 18.42
20.34 20.03
20.71 20.55
21.61 21.33
20.63 20.39
18.05 3.33
22.02 21.93
20.81 20.60
20.81 20.45
20.71 20.40
20.07 16.01
21.79 21.61
20.87 20.68
20.89 20.51
20.80 20.60
20.84 20.51
20.75 20.46
20.54 20.19