From: David R. Hendrickson [riffraff@eskimo.com]
Sent: Thursday, April 18, 2002 3:22 AM
To: 928
Subject: [928] Re: 928 digest: April 17, 2002


from a discussion on Phil Tong's mail list, apparently the Mustang 5.0
injectors are the exact same as ours ( it's all Bosch anyway ).  you just
have to use the 928 seal kits.  at $210 for a set of 8, i might give them a
shot when i do the intake...

Summit sells them:

http://store.summitracing.com/default.asp?target=%2Fdepartment%2Easp%3Fd%3D18

at this page select the Fuel Injectors link, then the "Ford Racing Hi-Flo
Fuel Injectors" link, then the 19 lb. injector link.  (it's all java so
there's no direct link to the items)

part no. FMS-M9593C302


dave

David R. Hendrickson
'88 S4 AT Silver Metallic
Kent, WA




From: Martin Bishop [mailto:martin@bishopemail.com]
Sent: Tuesday, February 25, 2003 1:16 AM
To: 928
Subject: [928] Re: Ford Fuel Injectors

> I need a set of fuel injectors for my engine fire damaged '91GT. I was only able to salvage two, the two farthest from the fire and they seem iffy. I would like to try aftermarket injectors due to cost (8 for the cost of 2 928 injectors). I searched the archives and did not find anyone that has tried them. Apparently, Ford Mustang and Chev LT1 injectors will fit as long as you use 928 O-rings (only S4 or later.) They are available in 19#, 24# and 30# sizes.
> Has anyone tried them? What size is compatible for a stock engine? Using injector calculators on web sites, it appears that 24# would be correct. Summit racing lists Ford and Accel for ~$220.
> I would like to order ASAP, and I am in digest mode, so, a direct reply would be appreciated.
> 
> Thanks, Earl Gillstrom '91 GT

Earl, 

I am running the 24Lbs on an 88S4 for about 9 months now.  They are
equipped with Porsche gaskets and "hats".  When you install them WATCH OUT
FOR KNOCKING THE HATS OFF into the cylinder.  You CAN fish them out in
about 1 hour each time.

I would recommend using a RRFPR and fuel pressure gauge to decrease the FP
after you increase the flow with the bigger injectors.  I have heard a few
opinions about Fuel Pressure, but for now I am running about 44PSI on
24Lbs.  I used an air flow meter to get a good setting, but would suggest
some thought process in tuning correctly.

Below is some great info that I collected on the topic.

Max Power is @ .875mV on the O2 or 12.6:1 Ratio

Stoichometric is 14.7:1

Fuel pressure with relay jumpered, engine off – 3.8 (54.74 psi) + or - 0.2
bar (51.86 - 58.02 psi) Stock with 57 being the optimal psi stock with
stock injectors.

It is at WOT where you will see the true RICH or LEAN reading from the
pressure you set. Other than WOT, the O2 does the work on tuning the
mixture.

The computer adjusts the air/fuel ratio at part throttle based on feedback
from the oxygen sensor. At full throttle the system goes into "open loop"
and ignores the signal from the oxygen sensor. It supplies fuel based on
full throttle maps programmed in to the LH computer and feedback from the
airflow sensor. For a given airflow it fires the injectors based on the
information in those full throttle maps. It doesn't know how much fuel is
actually being provided, but assumes that based on stock sized injectors
and stock fuel pressure. If the fuel pressure is raised or lowered, the
injectors will flow more or less fuel than the computer assumes, allowing
for adjustment of the mixture. At part throttle the oxygen sensor is again
monitored and the injector firing is adjusted based on that


Martin