peak-n-holds

[Bruce Plecan]

-----Original Message-----
From: rr <RRauscher at nni.com>
To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Date: Thursday, March 18, 1999 11:39 PM
Subject: Re: peak-n-holds

This must be ignoring the first half of the question asking if OK to run
Peak+ Holds injectors, on a saturated type driver.  Right?.
Bruce




>No, just changing the drivers won't make any difference. Both
>a P-n-H and Sat driver apply the full voltage across the
>injector at the start.
>
>It's only after the current reaches 4A (P-n-H driver), does
>the driver chip make a change in it's operation. That is, back
>off the current to a 1A level (hold).
>
>The saturated injector current won't even reach 1A, so even
>if the time-out circuit is used in the P-n-H driver, it won't
>make a difference. (This would be relative to a single injector
>per driver, such as a sequential system).
>
>-All of the above is relative to GM system's-
>
>BobR.
>
>For static testing of P-n-H injectors, use a 10-Ohm/10W resister
>in series with the injector and a 12 to 14 V P/S. It will open,
>and the current is limited, so no smoke. Can get them at the
>local RatShack.
>
>Mike Pitts wrote:
>>
>> Has anyone ever taken fuel delivery measurement differences
>> between peak-n-hold and saturated drivers, for the same
>> injector at the same PW and fuel pressure?
>>
>> My thinking is that the P-n-H drivers may open the injector
>> a little quicker, therefore delivering slightly more fuel
>> for a given PW.
>>
>> Just want to know ahead of time if the fueling is gonna
>> change when I upgrade my ECM.
>>
>> Thanks,
>> -Mike
>