Doug_B_928

So I think I have the procedure etc. all figured out. I went to give it a go and ran into a problem connecting the kit to the FD. See pic below. All of the connectors that came with the tester kit are too big to fit between the lines coming out of the FD on either side. How does one make this connection?

milwaukeeshark

Not sure what kit you're trying to connect, but if it's the CIS pressure gauge kit, the attachment is at the WUR not the fuel distributor. By the way, the Gunson Color Tune 500 is available at Moss Motors. As SeanR says an indispensable tool.

Doug_B_928

So both ends of the gauge attache at the WUR? That would make sense.

Thanks for the tip on where to get teh ColorTune.

bradartigue

Looks like you are testing the output pressure from the fuel distributor; to do this you have to temporarily remove the two fuel lines on either side of the outlet, then install the test connection, then reinstall.

You achieve the same result at the end of the hard line from the outlet, which is at the WUR.

Doug_B_928

So, to put it in simple terms for me, to engage in the various tests (cold pressure, system pressure, warm pressure and rest pressure), I connect the CIS test gauge up at the WUR with one end of the gauge connected to where the hardline comes to the WUR from the FD and the other end of the gauge where the other connection is on the WUR?

Thanks!

Doug_B_928

I just found this video on YouTube for the 930 and it answers the question. Both connections made on the WUR

Doug_B_928

Here's a pic of my connection of the gauges. I attached one end of the gauge set to the line coming from the FD (on the right in the pic). Then I attached the end of the gauge set with the valve to where the banjo bolt enters the WUR. When I tried it fuel was spilling out of opening in the WUR where the fuel line from the FD would normally enter. Did I do this wrong? Should I have hooked up the second end of the gauge set to where the fuel normally enters into the WUR from the FD and left the banjo bolt fitting and line into the WUR connected as normal?

Also, I wiped up the fuel where I could and sprayed compressed air. How long should I wait for the fuel to evaporate before starting the car?

Thanks, and sorry for all of these newbie questions.

Jadz928

That doesn't look right.

You just need to connect into the loop. Take off the top one (not the banjo) that goes to the top of the FD.
You have that one connected. Now just bridge that connection to where it screw into the WUR

The banjo one is the fuel return. Screw that one back in.

Doug_B_928

Thanks, Jim! That's very helpful.

Doug_B_928

Thanks to your help I finally got it connected correctly. I've attached a pic below in case there is anyone else as clueless as I was.

Here are the data:

1. Cold Pressure--14psi at 18C (normal at this temp should be 25-30psi)
2. System Pressure--76psi (this is within spec)
3. Warm Control Pressure--(I ran it with the key on but engine not running because I was afraid of a fire)--40psi (this is within spec)
4. Rest Pressure--a big fat 0! (should not drop below 25)

So, overall, cold pressure is maybe a little low, and rest pressure is non-existant. The symptoms of the car are rough cold starting (seems like not getting enough fuel for the first 5-10 seconds) and sort of a vapor-lock kind of symptom on hot starts (need to use WOT on hot starts to kind of blow out whatever is "clogging" the system).

As per Watson (p. 125 'Loss of Rest Pressure'), I pressurized the system, then closed the valve on the gauge. The pressure shot up to about 75psi. Then, I shut off the FP and the pressure dropped to about 40psi. He says, after closing the valve, "If there now is no loss of rest pressure, replace the control pressure regulator." Given what I found, I'm not sure how to interpret this statement.

Any thoughts on what is the likely cause of the results?

waynestrutt

I have a couple of colortune kits.You can borrow one if you want.I do not use mine because its like looking into the barrel of a firing shotgun. The clear ceramic body is what you look into to see the burning mixture. I would use an additional faceshield . To set the mixture use I think 3mm extra long allen key through the body of the mixture control unit.if you turn it clockwise it will richen the mixture.At idle the correct setting is achieved when turning the rpm rises slightly and then falls. If its too lean the rpm will rise If too rich it will fall . This can be done with all your airfilter and duct work installed .
Look here http://www.volvoclub.org.uk/tech/fue...jetronic.shtml

Luis_M

Cold start problem could be nonfunctional cold start valve at front of the plenum. Hot start problem goes along with poor residual pressure. Usual suspects include bad check valve at fuel pump, bad accumulator in rear passenger wheel well. If those are good could be a leaking injector. Can you confirm how you measured the rest pressure? Low cold control pressure is unusual. Someone has probably messed with the metal rod that is pressed into the WUR housing by tapping it in. Did you measure that with vacuum line on side to vacuum or without?

Doug_B_928

@Wayne--thanks for the kind offer. Looking into the barrel of a shotgun sounds kind of scary..... Thanks very much for the tip on how to set mixture by sound. I'll try that.

@Luis--To observe rest pressure I just turned off the fuel pump to stop the Warm Control Pressure test and watched the gauge (it dropped quickly). I did not disconnect any vacuum lines. Should I have?

The latter reminds me, is there supposed to be a bolt in the hole at the top back of the intake plenum? Mine hasn't had a bolt there for as long as I can remember. Could that affect vacuum?

Doug_B_928

Here's the procedure I followed, in case anyone wants to check to see if I made any (more ) mistakes:

1. Fire extinguisher handy.
2. Unscrew gas tank cap to let pressure escape from the fuel tank before disconnecting fuel lines.
3. Remove electrical connectors from auxiliary air valve and WUR.
4. Connect gauge set to WUR:
(a) Remove line on WUR where fuel enters it from the FD.
(b) Connect hose on the non-valve side of the gauge to that line.
(c) Connect the hose on the valve side of the gauge to the opening in the WUR.
5. Remove the FP relay.
6. Connect jumper (I used 6 amp fused with a toggle switch) from terminal 87 (load side) to terminal 30 (power side).
7. Wrap rag around release valve under gauge and depress button until air is released (never do this over a hot engine!).
8. Cold Control Pressure:
-valve open on gauge
-record pressure and ambient temperature
-compare to chart (+/- 3 psi)
9. System Pressure:
-close the valve on gauge
-record pressure
-should be 65-75 psi
10. Warm Control Pressure
-reconnect electrical on auxiliary air valve and WUR.
-open valve on gauge
-turn key on (or start car ensuring no fuel leaks first)
-watch pressure over 3-5 minutes
-pressure should rise and stabilize
-once stabilized, record pressure
-should be 41-46 psi
11. Rest Pressure:
-turn off key/stop fuel pump
-observe rest pressure over 20 minutes
-pressure should not drop below 25

ROG100

I first started using the colour tune on my 68 mini cooper.
I still have the original and it works fine and as Sean says perfect for 928 CIS cars.
Nothing dangerous about it at all.