Fuel Injectors

In 2004 (10k miles ago), I removed all the injectors and sent them in for an ultrasonic cleaning and assessment to The Injector Perfector.   After servicing them, he painted them gold (?) and replaced the fuel hose on each.  I have read that these early Bosch injectors are pretty reliable, but with all the effort I am going through to improve the fuel system, it made sense to have them checked again.

This time, I sent them to Performance Injection for assessment and service.  First thing he noticed was that one of the injectors was missing the inlet filter.

He then cleaned them up by removing the gold paint and clear coating the silver body, replaced the filters and bottom plastic pintle caps and ran them through his test sequence

And came up with the following performance results for each injector.

With this detail of information for each injector I can geek out and match injector flow to intake plenum flow.  The intake manifolds have unequal length plenums that result in CFM differences for each.

Mark Eaton, using CFD analysis has modelled the intake manifold and calculated the theoretical flow for each plenum.  He found a 2% lower flow in the four outside plenums compared with the two middle.  Using this information and the dynamic flow results, I have assigned each injector a location.

Injector	Dynamic Flow results	% to highest injector	Engine location	% intake plenum flow
1	104	98.7	1A	98.1
2	103	97.7	2A	97.9
3	104.2	98.9	6B	98.1
4	103.8	98.5	2B	97.9
5	103.4	98.1	5A	97.9
6	104	98.7	6A	98.1
7	105	99.6	3A	100
8	104.8	99.4	4A	100
9	104.8	99.4	3B	100
10	105.4	100	4B	100
11	103.8	98.5	5B	97.9
12	104	98.7	1B	98.1

With the serviced injectors, new seals and Gates Barricade fuel injection hose, I am ready to start assembling the new fuel rail and injectors.