[200q20v] 200 20v Fuel injector service and R&R (LONG)

[Peter Schulz]

Last week I finally removed the injectors from the 160 kmile 200 20v Avant 
and sent them to Marren Motorsports (Injector.com) for their injector 
"service".

Prior to the R&R, the car was difficult to start, with a pronounced smell 
of gasoline after it finally started.  Mileage was mediocre at best (high 
teens) and the plugs were continually fouling.  I initially replaced the 
fuel pressure regulator, which did not seem to do much, but mileage did 
seem to improve, but the hard starting and gasoline odor were still present.

Following tips from Gene Caldwell (Thanks Gene!) I ran the engine, pulled 
the fuse to the fuel pump, and let the engine die.  I then used a 17mm open 
wrench to remove the fuel lie to the pressure regulator, and a deep 10mm 
socket to remove the mounting bolts to the IM.  Next used the same 17mm 
wrench to remove fuel line to the fuel rail ( be sure to have rags to catch 
excess fuel that will drip and something under the engine to catch any 
excess - an be sure that the engine is cold for safety.  Pulled the fuel 
line/pressure regulator out of the way (towards the MC)  Used 10mm wrench 
to remove fuel line mounting bolt to fuel rail, then 5mm hex (allen) to 
remove fuel rail to IM mounting bolts.  Removed electrical leads to the 
injectors and the injector mounting clips to the fuel rail. Put a block of 
wood on the valve cover and used a big screw drive to carefully pry the 
injectors/fuel rail off the IM ( they are only held in the rail and IM by 
Viton seals at this point) It took a while and careful persuasion to pry 
them off.

Took out the injectors, took pictures  (Good technical description of their 
appearance: Yuck!!! surprised that the car actually ran!)
surface cleaned them covered them individually with bubble wrap and sent 
them out via express mail. Got them back two days later- with the following 
results:

injector   resistance   volume test  spray pattern
1                16              88.2               ok
2                16              93.6               ok
3                16              89.1               ok
4                16              85.5               n/g
5                16              87.3               n/g  aka (No good!)

all were found to be "dirty" on reverse cycle
after

1                                  90.9               ok
2                                  91.4               ok
3                                  90.9               ok
4                                  89.1               ok
5                                  89.1               ok

all passed leakage test.....

You can see how the variation from one injector to the next is greatly 
reduced....

Covered the injector inserts and carefully cleaned around the insert area 
with cotton swabs and rags soaked in carburetor cleaner. Then cleaned 
similarly cleaned the inserts.  Used a 3/8 inch SAE hex wrench to remove 
the threaded inserts from the IM - then cleaned the threads on the IM.  Put 
some motor oil on the IM threads and carefully inserted the replacement 
inserts and tightened snugly with same 3/8 inch SAE hex wrench.

Cleaned the ports on the fuel rail with cotton swabs.  Lightly oiled the 
new Viton Seals that came on the cleaned injectors, pressed the injectors 
into the rail, installed the locking clips, carefully pressed the 
rail/injector assembly into the IM ports. Reinstalled rail mounting 
bolts.  Attached electrical connectors to injectors.  Reinstalled the 
pressure regulator and fuel lines.  Put new metal seals on the 17mm fuel 
line banjo bolt on the fuel rail, gently tightened.  Reconnected 17mm fuel 
line to pressure regulator.

Checked all connections.  Install fuel pump fuse, start car and carefully 
(CAREFULLY!) check for fuel leaks around the lines and banjo bolts.

Immediate impressions - car starts much more quickly, no gasoline fumes 
detected, and throttle response crisper.  Mileage seems to also be 
improving.  Once the photos are developed, I'll scan them and ask Chris 
Miller to post them on his 200 20v web page.

Thanks again to Gene for his directions.  I am very satisfied with the 
results and wish that I had done it much earlier.

Peter Schulz
1990 CQ
1991 200 20v TQW
Chelmsford, MA USA
peschulz at cisco.com