fuel delivery problem - Page 2 - Alfa Romeo Bulletin Board & Forums

Reply
 
LinkBack Thread Tools Display Modes
post #16 of 97 (permalink) Old 03-17-2005, 09:35 AM
Senior Member
Platinum Subscriber
 
Roadtrip's Avatar
 
Join Date: Jan 2003
Location: Rapid City SD, Black Hills of South Dakota, Queens NY
Posts: 9,404
Send a message via Skype™ to Roadtrip
Again, forgive me, but I'm not that familiar with Montreal injection pumps. They are, however, basically two 4-cylinder pump bodies bolted together with a common logic section at the rear.

Are the 4 cylinders that are not getting fuel all in the same pump body?

I'm looking for something in common that would affect 4 separate cylinders all of a sudden. I've got a hard time believing that you could have done anything by your cleaning operation other than kinking the fuel pipes . . but you say they're clear with no blockages.

You didn't by chance reverse the fuel hoses (supply and return) to the injection pump. I would think that would be obvious, however, due to the length of the hoses.

John Stewart
74 Spider
91 164S

Last edited by Roadtrip; 03-17-2005 at 09:45 AM.
Roadtrip is offline  
Sponsored Links
Advertisement
 
post #17 of 97 (permalink) Old 03-17-2005, 12:26 PM Thread Starter
Registered User
 
Join Date: Dec 2004
Location: Ireland
Posts: 47
It too different sides of the pump body. These problem cylinders correspond to the two nozzles I removed.

I have attached a photo...

I only removed the supply line to the pump so couldn't have swapped them around.


I also removed the injector nozzle today on number 4, and turned on the ignition to allow the fuel pumps to run. This time, I see lots of fuel spurting out --- the injector head is really just a metal casing with a spring and which holds the jet in place....
Attached Images
 

Last edited by ar15625; 03-17-2005 at 12:29 PM.
ar15625 is offline  
post #18 of 97 (permalink) Old 03-17-2005, 03:39 PM
Senior Member
Platinum Subscriber
 
Roadtrip's Avatar
 
Join Date: Jan 2003
Location: Rapid City SD, Black Hills of South Dakota, Queens NY
Posts: 9,404
Send a message via Skype™ to Roadtrip
First of all . . . . Happy St Patrick's Day! I imagine you're drinking a lot pints rather than fixing Alfa's today!

Ok. But you've got me confused now. You said before that 3,4,5, and 7 didn't have any fuel.

But now, you say only numbers 3 & 4 are the problem (in the picture), but 4 spurts fuel with the fuel pump running? How about the other problem cylinders?

Next, lets get some nomenclature correct so we're talking about the same objects:

1. The metal things sticking up on the top of the injection pump are the "Fuel Towers," not "injectors." They house the Check Valve Return Spring.

2. The "Injectors" are at the end of the fuel pipes and screw into the intake manifold.

3. Beneath the Fuel Towers is a spring and a (one-way) "Check Valve." The purpose of the check valves is to keep the fuel pipes pressurized and prevent backflow. These check valves are hand-lapped to their bases and are NOT interchangable. Unless you know what you're doing it's better to leave them alone. See picture below.

Loosen the fuel pipes at the Intake Manifold INJECTORS and crank the engine over on the starter only for about 20 seconds (without actually starting it) and see if you get any fuel out the pipes. Do overheat the starter doing this. What I'm trying to do is purge the fuel pipes of air. When installing a new pump, it's good to remove the spark plugs (easier on the starter motor) and crank the engine for 20-30 seconds or so to get solid fuel to the injectors.

BTW, if you look into the intake bores with the butterflies wide open, can you see the injector tips? If so, you should look for the spurt of fuel when you motor the engine on the starter.

Top picture is what's directly under the Fuel Tower.

Bottom picture is of a Fuel Injector + one that's disassembled.
Attached Images
  

John Stewart
74 Spider
91 164S

Last edited by Roadtrip; 03-17-2005 at 03:44 PM.
Roadtrip is offline  
 
post #19 of 97 (permalink) Old 03-18-2005, 04:56 AM Thread Starter
Registered User
 
Join Date: Dec 2004
Location: Ireland
Posts: 47
thanks. St Patricks Day is always a big event here, and a public holiday....I took it easy on the pints last night so I can be fully awake for the Montreal maintenance today

Just to confirm that 5and7 are also not working. I just removed the 'towers' at 3 and 4 to confirm the lack of fuel.

The other tests (check exhaust manifold temperature) was done on all cylinders.

I will take a few more photos today as I run the tests you mention.

Given the assembly that is behind the 'towers' -- its hard to see how anything I did during cleaning could have affected the fuel flow.
ar15625 is offline  
post #20 of 97 (permalink) Old 03-18-2005, 06:54 AM
Senior Member
Platinum Subscriber
 
Roadtrip's Avatar
 
Join Date: Jan 2003
Location: Rapid City SD, Black Hills of South Dakota, Queens NY
Posts: 9,404
Send a message via Skype™ to Roadtrip
I'll ask again, because the SPICA system often gets blamed for ignition problems. Have you checked that you're getting spark at those cylinder? Do you have an inductive timing light that you can confirm spark with?

I still can't see how you could have done anything except drain the fuel pipe when you loosened it . . . and that's never a problem since it should fill back up (although the engine might run rough for a few seconds until the air is purged).

Ok. If the purging doesn't restore normal operation and you're absolutely positive that the ignition is good, we can go on to the next easiest step . . . . checking the Compensator Link Retaining Spring.

In the picture below, remove the three screws indicated. DO NOT remove the screw labeled "NOT THIS SCREW." The picture is of a 4 cyl pump, but yours is the same except for the cable-driven temperature adjustment lever. Lift the Barometric Compensator (BC) straight out. It's not super fragile, but you want to be very careful with it anyway. Smell it. Does it smell like stale gasoline? If it does, it could be that the pump is worn and is leaking fuel past the plungers & barrels. Wrap it in a soft rag and set it aside somewhere where it won't get damaged.

Next take a flashlight and look in the cavity. You'll see a spring just forward of the opening. It should be attached at the top by being threaded on the screw and on the bottom at that link arm. DON'T MOVE THE LINK ARM. You can put slight pressure on the spring just to be sure that it's not broken anywhere. Broken Compensator Link Springs are not uncommon in old SPICA pumps. Corrosion is the usual culprit.

If the Spring looks ok and while you have the BC out, pour about a half pint of clean engine oil into the cavity to refresh the oil supply. Don't worry about too much, the excess will drain back to the engine sump.

Replace the BC. Also, you should replace the missing screw to the Thermostatic Actuator (T/A) indicated at the arrow. It's a 4mm screw at least 6mm long (longer is OK).

Here's some other pictures so you can see what the components look like inside the pump.
Attached Images
    

John Stewart
74 Spider
91 164S
Roadtrip is offline  
post #21 of 97 (permalink) Old 03-18-2005, 11:04 AM Thread Starter
Registered User
 
Join Date: Dec 2004
Location: Ireland
Posts: 47
Hi

After removing the BC, the spring looks fine, Although it does look very unlubricated in there. The BC looked ok, no smell of fuel -- it just looks a bit brown and old.

I add about 1/2 pint of oil (10w40) --- I have also added 2% oil mixture to the
fuel as specified by the Montreal manual for lubricated the spica pump when it has been laid up for a long period of time.

I stll need to run the test to see if I am getting fuel squirt into the cylinder by looking in past the throttle butterlies.

photos attached of BC and the spica oil filter
Attached Images
  
ar15625 is offline  
post #22 of 97 (permalink) Old 03-18-2005, 02:22 PM
Senior Member
Platinum Subscriber
 
Roadtrip's Avatar
 
Join Date: Jan 2003
Location: Rapid City SD, Black Hills of South Dakota, Queens NY
Posts: 9,404
Send a message via Skype™ to Roadtrip
That BC looks like it's been dry for a very long time. It's even rusted. That's not good. Hopefully the bearings are haven't been worn badly in the pump. One item that wears even with lubrication is the cam follower and it's little ball bearing that rides on the 3D cam like a phonograph stylus. With bad lubrication it can get flat spotted from not being allow to roll in it's socket. When that happens the mixture leans out, then if the ball suddenly rolls around to a non-flat spot, the mixture suddenly changes and you're wondering why it won't stay in tune.

If the logic section is that dry, it probably wouldn't hurt to spray some thinner spray lubricant around the inside of the logic section to try and get into all the linkage joints.

It also looks like that oil filter hasn't been changed in the past 10 years either. It's a shame that the previous owner didn't take better care of a such a beautiful and rare automobile. That filter is a lot longer than the ones in the 4c cars.

Also, as point of reference, I just noticed that the picture I posted of the cutaway pump above is a 1969 4c pump and has a slightly different logic section from yours. Specifically, the 69s don't have the Fuel Cutoff Solenoid, its microswitch and linkage like the Montreal and later 4c versions.

BTW, I don't know if you know about this Montreal website, but it's outstanding. Lots of great info on Montreals, including the SPICA system.

http://www.alfamontreal.info/

John Stewart
74 Spider
91 164S

Last edited by Roadtrip; 03-18-2005 at 02:29 PM.
Roadtrip is offline  
post #23 of 97 (permalink) Old 03-18-2005, 02:38 PM Thread Starter
Registered User
 
Join Date: Dec 2004
Location: Ireland
Posts: 47
I think I will now remove the pump to investigate in more detail.

The inside of the control section -- at least what i can see thro the BC port is also lacking in oil. A little squirk of WD40 should help.

To do this, I can see two nuts at the bottom of the control section, do you know exactly where the pumping section is secured ?

Thanks for the montreal site, I am a member of the UK club also. The montreal site is excellent and I have been asking for help there also. but you are the recognised spica expert !

If all else fails, I guess I can spend the pump to Wes Ingram for rebuilt.

In some ways, its a testament to the Monti that although its only really running on 4 cylinders it still starts....
ar15625 is offline  
post #24 of 97 (permalink) Old 03-18-2005, 03:01 PM
Senior Member
Platinum Subscriber
 
Roadtrip's Avatar
 
Join Date: Jan 2003
Location: Rapid City SD, Black Hills of South Dakota, Queens NY
Posts: 9,404
Send a message via Skype™ to Roadtrip
At this point I wouldn't recommend that you remove the pump. There's really nothing that you can do for it. Opening up the logic section is pretty easy, but getting it back together is a little hard because of the several parts that have to line up, plus the large governor ball bearings that are hard to keep in place. There's absolutely nothing you can do for the pump section as an owner-mechanic. You need lots of experience and a test bench to calibrate and balance the fuel delivery plungers.

Spray that BC with some WD-40. Press on the bottom of the bellows using just a little pressure to see if moves. It should move slightly, then spring back to where it was before.

The whole SPICA pump is held on by the six nuts on the front pump section, and probably a bracket on the bottom of the logic section. To detach the logic section from the pump sections, you have to remove the six bolts, break the logic section in half, then take out four screws underneath the governor bowl. Trust me, you don't want to do that unless you know what you're doing. The end result will probably that you send a box of parts to Wes Ingram.

Besides, a Ingram overhaul for a Monty pump is about $1200 US (I suppose about a 100 Euros right now with the exchange rate ). No sense in having that done unless it needs it. Since the BC and logic section didn't smell like gas and you're not getting oil dilution, I think the pump sections are in ok shape.

John Stewart
74 Spider
91 164S

Last edited by Roadtrip; 03-18-2005 at 03:13 PM.
Roadtrip is offline  
post #25 of 97 (permalink) Old 03-18-2005, 03:34 PM Thread Starter
Registered User
 
Join Date: Dec 2004
Location: Ireland
Posts: 47
Ok. I will lubricate the BC.

Any ideas/suggesstions on what to try next ?
ar15625 is offline  
post #26 of 97 (permalink) Old 03-18-2005, 05:43 PM
Senior Member
Platinum Subscriber
 
Roadtrip's Avatar
 
Join Date: Jan 2003
Location: Rapid City SD, Black Hills of South Dakota, Queens NY
Posts: 9,404
Send a message via Skype™ to Roadtrip
Have you checked spark again, AND made sure that the firing order of the plug wires is absolutely correct. I spent about 3 hours on the phone one day with an owner have "fuel" problems who swore to me that the firing order was correct, only it really wasn't. Said he looked at them several times, before realizing that they were wrong. Swapped a couple of plug leads and . . . voila. Since you're getting no fire in 4 cylinders, the numbers add up to possible crossed wires.

We don't want to have you as the latest "Poster Child" for blaming the SPICA system when it's really ignition that's the problem. That club's big enough already.

Are you still coming up dry when you loosened the fuel pipes at the injectors, then motored the engine for a while to try and prime the fuel pipes?? How about if you remove the fuel pipe at the fuel tower on the injection pump, then motor the engine?

I still just have a really hard time believing that you're not getting fuel to several seeminly unrelated cylinders, and all of a sudden also. The chances of the pinions slipping on four plungers at the same time is about zero, and that's the only thing I can think that would cause no fuel delivery in a specific cylinder. Injector blockage is not common at all due to the very high pressure.

You can also try swapping a good (manifold) Injector with a one that's not putting out fuel to see what that does. That may confirm a blocked injector, but I really doubt that's the cause, since 4 injectors wouldn't go bad all at once.

Tell me again, exactly . . . what you did when you "cleaned" the lines.

1. Which lines did you clean? Just the ones that we think are malfunctioning, or some of the others also.
2. What exactly did you do to clean them.
3. What parts did you remove?
4. Was there a lot of dirt around that could have gotten in the lines?

John Stewart
74 Spider
91 164S

Last edited by Roadtrip; 03-18-2005 at 05:49 PM.
Roadtrip is offline  
post #27 of 97 (permalink) Old 03-19-2005, 03:42 AM Thread Starter
Registered User
 
Join Date: Dec 2004
Location: Ireland
Posts: 47
thanks. Here is the exact details of the cleaning I did


1. Removed the air filter cover and air equaliser tubes (monti only I think)
2. removed the part plugs one by one and replaced with golden lodge 2hl
3. Using 17mm spanner, loosened the nut of fuel line 4 at the spica tower
This was tight but moveable by hand.

4. removed the pump fuel-in connector as it gets in the way.
5. Loosened the other end of fuel line 4 (injector end).
6. Removed injector 4 and gave it a clean (using carb cleaner)
7. Blew some air throught the fuel line 4 (from a small battery driven air pump)
8. Squirted some carb cleaner into the tower of number 4

Repeated the same with fuel line 3

In general, everything looked reasonable clean. There was small amounts of corrosion (white substance) around the fuel lines at both ends). The top of the pump was quite dirty at the tower.

At this stage, I replaced everything to check for leaks and go for a little run. I then noticed the very poor running (hesitation)

Note: the original reason I started this was that the car was becomming very diffiuclt to start and had run a battery flat --- I recharged the battery
ar15625 is offline  
post #28 of 97 (permalink) Old 03-19-2005, 07:42 AM
Senior Member
Platinum Subscriber
 
Roadtrip's Avatar
 
Join Date: Jan 2003
Location: Rapid City SD, Black Hills of South Dakota, Queens NY
Posts: 9,404
Send a message via Skype™ to Roadtrip
I still think the problem is electrical. Personally, I don't like the Lodge plugs. I like standard-electrode NGKs.

Clean and regap your old plugs, re-install them, and make triple sure that the firing order is correct.

John Stewart
74 Spider
91 164S
Roadtrip is offline  
post #29 of 97 (permalink) Old 03-19-2005, 10:54 AM Thread Starter
Registered User
 
Join Date: Dec 2004
Location: Ireland
Posts: 47
Finally got around to running the car on the starter with the throttles opened...

I can see spurts of fuel in 1,2 6 and 8 -- the others are dry

Attached are some photos of the spica pump towers that -- you can clearly see a twinkle of fuel on the first two (to the right) while the others are dry.

I also removed the pipe for 1 and 2 (after the test above) and guess what --- Now no fuel getting into 1 and 2 --- the car wont even start now....

Attached also is a photo of the assembly at the tower of the spica (for 3 and 4)
Attached Images
  
ar15625 is offline  
post #30 of 97 (permalink) Old 03-19-2005, 12:22 PM
Senior Member
Platinum Subscriber
 
Roadtrip's Avatar
 
Join Date: Jan 2003
Location: Rapid City SD, Black Hills of South Dakota, Queens NY
Posts: 9,404
Send a message via Skype™ to Roadtrip
They do look dry as a bone. I'm starting to believe you. It looks like you've taken the fuel towers off two of the dry ones. Keep track of which washers and how many are in each tower. Don't mix up the springs if you can help it.

Normally I don't recommend that owner delve into the pump section by removing the towers. However, since you've already done it you can try the following if you feel brave.

With the fuel tower off reach down with a some needlenose pliers and pull out the check valve. Inspect it and the bore for junk. When you look straight down the bore area, you should see the plunger at the bottom with a hole in the center (a machining mark) and at one edge a small cutout. When you manipulate the throttle you should see that cutout rotate with the plunger.

If it's not stuck in there good, you might be able to pull the check valve seat out of the bore with some needlenose also. Carefully note the position and install in the same relative rotational position in the bore, just to be extra safe.

Rotate the pump until you see the plunger at the bottom of it's stroke. At that point two fuel inlet holes are uncovered and there should be lots of fuel running into the bore with the fuel pump running. If you're not, there must be some blockage internal to the pump fuel manifold or the injection pump isn't getting any fuel from the supply pump.

The pictures show removing the check valve and it's base. The last picture is from a guide I haven't finished yet on the theory of operation of the SPICA pump. It shows the flow of fuel from the manifold, throught the barrel, check valve and out the top to the fuel pipes. In the diagram, however, it's shown with the check valve and spring in-place. With the check valve out and the plunger at the bottom of its stroke, fuel should flow freely through the barrel and out the top of the pump.

Past this, I'm at a loss to help. An email to Wes Ingram would be worthwhile since he's the real expert.
Attached Images
   

John Stewart
74 Spider
91 164S

Last edited by Roadtrip; 03-19-2005 at 12:25 PM.
Roadtrip is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome