4000Q Fuel Q: LONG: DPR Differential Pressure Regulator

[SuffolkD at aol.com]

No progress yet.  Car sitting.  Drove to Long Island and the car hinted at a 
miss at freeway speeds, accelerated well otherwise.  Park car and next morning 
car won't idle, dies, then runs rough.......

Notice igloo cooler top (ur-Q one: its a Mc1 turbo conversion) isn't held on 
by anything, loose, firmly seal igloo top by hand after either spraying. 
However, the PO kept the JT 4000Q fuel system and ECU.

Later in day see spark arcing from # 3 spark plug wire to shroud over plug.  
Get parts.  
Clean cap and rotor contacts.  They didn't have right one.
New wires and single electrode plugs gapped down from .042 to .028, within 
specs of .025 - .035.  Old plugs had light ash and 4 electrodes.
Could start car with either/starting fluid but engine dies after either is 
spent.

Replace fuel filter with 5000 model, same I just took end fitting off to fit 
4000Q.
inside batting seems gray to black but no visible dirt particles floating 
around.  (once I had one PLUGGED in another 4000Q, which fouled the Diff Pressure 
Reg*)

Carb cleaner the Diff Pressure Reg oriffices.  No voltmetter to measure 
continuity or Ohm values.  (old one in another 4000Q was bad * showed open circuit 
or infinity reading, replaced with junk yard one @ 460 or so Ohms value and 
Viola! new car!)

Audible fuel pump energized buzz/relay sound when key turned on in ignition.

Techron put into gas tank.
Add 5 gallons of new fuel.

Start on either, put foot into throttle and IF I don't move my foot, I can 
keep it at 3000 RPM's kinda smooth for 10 -15 minutes at a time, dies at idle, 
stumbles, runs rough.

Repeat process hoping to clear something out.
Revs decent from 2500 to 4000 and using foot to feather throttle get it down 
to 1500 RPMS.

Drive 250 miles home to Boston.  Moving is fine, but limited to about 60 MPH, 
80 on long downhills but unsustainable.  Idle is by foot and held to at least 
1000-12000 RPM to keep from stumble or dying.  I got more gas (6 gallons) and 
igloo top popped off when car died: Backfire?,  replaced /sealed igloo with 
either sprayed into it to start again for the next 100 miles..

Watching vac readings and boost gauge:
Car used to accelerate under -10 vac (light throttle), now constant running 
under vacuum, but to accelerate I need 1 - 2 PSI constantly.
Car is set to 5 PSI, and at 5PSI no preformance increase, just creating 
heat......

I'll check:  Timing belt, FPR and Fuel accumulator and Fuel PUMP filter (in 
line from tank to pump says Bentley page 20.9.

Other ideas?

-Scott by BOSTON



tfh400036 at yahoo.com writes:
> So, the question is, are you making any progress on this car? Did you pull 
> the plunger out of the fuel distributor?
>  
> What are the symptoms again?
>