924Board.org

[oldgoaly]

Well Bentley manual is here, copies of hp and bosch technical manuals at our side knocking individual tests of one at a time.
system running pressure was 60-65 psi, with a .040 shim (19ga steel) 75lbs
residual pressure was 20-22 psi, now with shim 28 psi
Fuel pump flow (thru filter) 1005 cc in 30 seconds.
a few other things of note, gas is darker that it started, replacing gas now, and the auxiliary air valve is electrically disconnected, terminal junction cut off.
Right now starts quickly then stops after a couple of seconds, hold cold start/hot start fix button in it stubbles for about 10 seconds.
Your thoughts? Thanks for the help! tt

[Ozzie]

how is the spray pattern from your injectors?
Have you pulled all 4 out and tested the flow by lifting the control arm in the CIS?
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[oldgoaly]

Ozzie,
that is on the list. we just pulled fuel gauge sending unit cause the color of the gas has darken, we appear to be melting a reddish residue with the new gas (yes we put injector cleaner in gas). OH ya we have noticed you have to drop the transaxle to clean the tank as We would normally do it, welded seams get hot tanked in a lye solution, soldered seams no lye, pc of chain, of course cleaned with mek. Here we use Damon's Red-Kote.
So looking for a work-a-round of a gas tank removal??? and the discoloration? could it be some type of fuel stabilizer? or lead/octane additive??? so close but no vroom vroom.
Thanks for the help and support! tt

[Ozzie]

red usually = rust.
The internal filter and pickup can be unscrewed from the bottom of the tank.
If the filter is blocked it will cause problems similar to what you describe.
The fuel turns to a jelly like varnish after years in the tank.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[oldgoaly]

Ozzie, I gotta laugh! We have been working on a 50 Studebaker now that is RUST! I haven't been under the car Joel is the one who has, so I'll get him under there and see what holds it in. I did clean the fuel sender with lacquer thinner, very easy to clean,. Now thoughts of 5 gals of cheap lacquer thinner and a recirculating pump? Take care! tt

[oldgoaly]

Well tank is clean! surprisingly clean, turning our attention back to starts easy dies within 5- 10 seconds. Coil voltage, at start up 6-8 volts dc, as it sputters it's dropping 6-4volts dc. cleaned and checked ballast resistors, they are on spec 04 ohms stamped in metal (meter shows .4 ohms) so.... looking for resistance in coil circuit and need to check control module (or what ever bosch calls it) Noticed a haynes blooper basic coil resistance check..... Hmmm wonder how many there are???? Take care! tt

[Ozzie]

have you checked fuel flow at injectors?
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[oldgoaly]

Have not looked at injector spray pattern as of yet. will do that today. tt

[oldgoaly]

Surprisingly how easily the injectors came out! ok bad news only one sprays, with injectors removed from banjo fitting, not gasoline is getting thru. Did spary carb cleaner thru injectors and spray pattern is pretty good thru them now. Soooooo looks like we need to take apart the control valve as there is 75-80 psi of gas input, only one spraying....... that looks to be a major problem! Are WE having fun yet? <<<grin>>> Can't give up now! Thanks for the help! tt

[Ozzie]

I hope you checked it this way:
To check the fuel flow at the injectors you have to make sure the pump is running then lift the air mass flap on the CIS.
Its described better in the Haynes manual.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[oldgoaly]

I did not lift the flapper on the control valve, with 3 not spraying we pulled the lines off and blew air thru, pulled the top of control valve blew some carb cleaner thru it, reassembled, no change. So then he got distracted "a girl" end of work for the day..... So before dissembling raise flapper and see if others start spraying or flowing gas? Thanks for the HELP! This is all new to me, starting to make some sense.....

[RC]

Don`t disassemble the control unit yet, if ever.
Lift the plate with pump running and watch all injectors. The "good" one may be leaking or opening at a lower pressure. Allow heaps of fuel to squirt out to flush system. Drink 4 beers beforehand to provide injector holders.

The fuel flow (relative to airflow) is adjusted by a 3mm allen key in the appropriate hole. This slightly raises or lowers the control piston. Rotate clockwise for more fuel. Very likely this has already been screwed with anyway but take note of initial position. The adjustment range falls well within 1/2 turn.

[oldgoaly]

uh oh.... well I got back to the garage just to see it come apart.... ok we did find 3 (instead of 4) clogged screens in the top of the control valve on the outlet side. the O-rings inside the c-v were a mess, We matched up some and put it back together "hopefully" the correct way..... it came apart with springs washers flying about, but using some logic (which can get you deep in doggie doo doo) reinstalled, jumped fuel pump gas flowing out of each injector line, put injectors on, fuel flowing equally from 3 of the 4, one has a 270 degree pattern, so it will soak in carb cleaner then sprayed till it's clean. It looks like it sprays allot of gas in a short time. Maybe I missed it but I sure don't remember reading about those screens in the c-v. Thanks for all the help! tt