You say there's a good fuel spray while lifting the sensor plate but not while cranking. Have you tried lifting the sensor plate manually while cranking?

Brett, I assume that the sensor plate isn't lifting during cranking because the injectors didn't spray into catch bottles until I lifted the plate. Tensioners are the type used in '83, one MY before the Carrera type were phased in. No evil sounds noted back when this thing actually ran, so I've got my fingers crossed.

Fred, vacuum leak test is next. Steve, I did try lifting the plate while giving it a good crank, to no effect.

One thing I stumbled across recently is one of the two plugs was missing from the aluminum casting at the brake booster. Plugging it didn't change anything, and I'm hoping an airbox-cracking hiccup wasn't why the plug was missing.

I'll post the fuel pressure test readings within the hour.
Jeff

Glad I can help, the connector in the picture is from a 74 with an 090 WUR. I have a 77 with a 3.0sc engine and the connector looks like this......

http://forums.pelicanparts.com/uploa...1317257912.jpg

fuel pressure readings
 

Using Jim William's write up & Bentley as a guide, these are the fuel pressure test readings taken with engine at ambient temp and not running of course:

System pressure: 70 psi

Cold control pressure, wur unplugged: 35 psi (~2.5 bar)

CCP, wur plugged in: 48 psi (3.3 bar)

Residual pressure, test valve to wur closed: dropped from 40 to 24 psi in 20 min

Residual pressure, after test valve to wur was then opened: dropped 1 psi in 35 min

The 2.5 bar CCP looks OK on the Bentley graph for an 83, but the car wasn't running so I'm unsure if this reading is within spec.

On an unrelated note, in prep for vac leak check, any problem or trick to get the the black rubber boot on top of the engine removed with engine in place?

Thanks,
Jeff

Jeff,

What was the ambient temp when you checked the pressures?

matstermag,

Temp was 75F

Thanks for the last photo, that matches my plug. I found out that the U shaped clip under the plug (you can see the ends of the two legs in your pic) doesn't need to come out since it holds the bottom, male part of the plug to the wur body. The upper, female piece disconnects from it exactly as you described.

Sorry I misspelled your name back a bit.

Cold control pressure.........
 

Jeff,

The cold control pressure @ 48 psi is too HIGH!!!!! When did you take the reading? This could be the warm-up control pressure already. With a CCP of 48 psi., I doubt if you could get it to start cold. Plus you have not verified or confirmed the absence of vacuum/air leak at this point.

Now, that you have the fuel pressure gauge hook up, test the WUR. Run the FP by jumpering the FP relay socket (87a-30) with a suitable jumper preferably with in-line fuse. Observe and record the time and pressure on the gauge. Here is an example:
Initial
15 sec.
30 sec.
60 sec.
90 sec.
120 sec.

Continue until the control fuel pressure stabilizes and post these numbers for us. Keep this record for your reference in the future. Keep us posted. Thanks.

Tony

Jeff,
Just a thought,Didn't you say that when you manually introduced fuel via spraying down the TB you had no change and no indication of it trying to start? You have verified spark, introduced outside fuel,and still no luck. Checking all the pressures and for vacuum leaks is a must, don't get me wrong, but I still think compression test. Could be why the sensor plate is not lifting while cranking?

I would say that looks ok for now @75 deg according to my Bentley also,as long as when you say WUR plugged in you mean electrically and jumped with 12v for a couple minutes. I also have a Bosch K-jet service guide but the graph is showing different then the Bentley. I have to do more research before I can quote real figures. Stay with Tony on that, hes on the ball. Keep us posted!

Tony,

The CCP was 35psi with the electrical connector unplugged from the wur. It started to rise to when I plugged it in and stabilized at 48 after a minuter or two. It ramped up fairly quickly.

When you say to test the wur, do you mean something different than what I've already done? I'll try getting time lapse readings of the pressure rise tomorrow. BTW, the pump was running continuously from start to finish of these steps.

I used jumpers long enough to reach the FP switch while at the back of the car.

Thanks and have a good evening, Jeff

FP test.......
 

Jeff,

What FP switch you are referring? This is something new to me (???). The most popular or common method guys used is the FP relay set-up. Are you familiar with this procedure? I prefer this technique because it allows you to check both the FP and AFS (air flow switch). Or maybe we are talking the same thing. Please advise.

Tony

I'm referring to the temporary switch I wired with a jumper to the pump relay terminals to allow running the pump during testing. It's the method in Bentley. I didn't want to have to run back and forth to the front of the car to use it, so I used wires long enough to reach the rear of the car.

I just found Scott K's thread about his SC starting problems. Looks like a great thread for me to read through. You said you were in Carmel in August. So was I, during car show week. Is that when you were there?
Jeff

Finally got to checking pressure rise vs time with wur attached to the pressure gauge. The wire to the wur was connected. Switched on fuel pump and recorded:

15 sec : 35 psi
30 sec : 40
45 sec : 47
60 sec : 49
90 sec : 50
120sec: 50

This seems consistent with numbers posted in a few other recent threads about CIS issues.
WIWIT, I measured 10 ohms across the wur terminals. So, is the book closed on fuel pressure issues , and now onto leak checks?

I have to take a week off from my troubleshooting, and look forward to people's input when I return.

Thanks to all - Jeff
83 911SC

Carmel-by-the-Sea..........
 

Jeff,

Since one of my sons moved to Carmel, I've been visiting them every August. And lucky for me, they also have the famous car shows in town in late August. It is mind boggling to see those very expensive collectible antique cars parked on the street. I'll be there again next year.

Tony

cis hot sits and floods
 

runs great, starts good when cold, starts good after 3-5 minutes sitting when hot, after that has to crank for about 8-12 seconds then sputters then runs great again

Start another post.........
 

If you want more detail replies to your problem/s, I would suggest that you start a new thread. Include more specific description of the problem/s you are having and actions taken. BTW, I would check first your residual fuel pressure before doing any serious troubleshooting. Keep us posted.

Tony