1.9TD AAZ fuel pump issues
- Thread starter CaddyJim
- Start date
ToddA1
Top Post Dawg
Yes, that’s what I meant. What was the previous fueling issue?
I have nothing else to add other than spinning it with a drill, as I’d previously mentioned. Maybe the vanes in the pump aren’t entirely moving freely?
-Todd
I have nothing else to add other than spinning it with a drill, as I’d previously mentioned. Maybe the vanes in the pump aren’t entirely moving freely?
-Todd
The guy I bought the car off said it had air in the fuel system but I bled the air out pretty quickly and the car still wouldn’t start. I then guessed it was more likely a fuel pump issue. Any idea what would stop the vanes moving? I disassembled and reassembled the pump twice and didn’t see any issues when I was turning it on the bench.
burn_your_money
Veteran Member
The vanes aren't really related to fuel injecting out of the delivery valves. The vanes only fill and pressurize the pump, the head and rotor is what builds the high pressure to force fuel into the engine cylinders. From the sounds of it, the pump isn't having issues moving fuel through the IN/OUT bolts.
The large 3 sided plug on the end of the pump head (the timing dial indicator screws into it) - how tight is it? It should be at around 100 ft/lbs. It is technically a one time use piece but they often can be reused. They have a knife edge that crushes against the head to seal the top of the high pressure area. If that is bleeding pressure, you won't get enough pressure generated to overcome the spring force on the delivery valves.
The large 3 sided plug on the end of the pump head (the timing dial indicator screws into it) - how tight is it? It should be at around 100 ft/lbs. It is technically a one time use piece but they often can be reused. They have a knife edge that crushes against the head to seal the top of the high pressure area. If that is bleeding pressure, you won't get enough pressure generated to overcome the spring force on the delivery valves.
BYM, it is highly likely that the plug you are referring to isn’t tight enough as I definitely didn’t tighten it to 100 ft/lbs! I used an adjustable spanner to tighten it as I couldn’t find another way of doing it. thanks for the info, I’ll order a new plug just now and find a better method of tightening it then report back!
Cheers!
Cheers!
burn_your_money
Veteran Member
Land Rover 200 & 300 Tdi Bosch VE injection pump specialist socket tool set | eBay
3 sided / triangular 7mm - 1/4" sq or 15mm hex drive. 3 sided / triangular 12.6mm - 1/4" sq or 1/2" sq (external) drive. 3 sided / triangular 14.4mm - 1/2" sq drive. 3 sided / triangular 26mm - 1/2" sq drive.
www.ebay.co.uk
I'm not recommending this particular product but you should try buying the proper tool. The proper torque might be all you need.
If you use a new one, the torque spec is considerably lower. Best to ask the seller what to torque it to (and then post back to let us know).
ToddA1
Top Post Dawg
Ah, so you’ve never personally had this car running? I think we all thought you did, by your earlier post.
Fwiw, I’ve resealed many IDI and TDI pumps and have always reused that triangle plug. I’ve always tapped on a 1” or 25mm wrench on it, then snugged it up. All of my resealed pumps worked fine.
-Todd
Fwiw, I’ve resealed many IDI and TDI pumps and have always reused that triangle plug. I’ve always tapped on a 1” or 25mm wrench on it, then snugged it up. All of my resealed pumps worked fine.
-Todd
BYM, thanks will find out the torque spec and grab a tool for it.
Todd, it fired up once after I bled it but then to my surprise never started again after that. That’s when I started on the fuel pump. I may have made the problem worse but it wasn’t starting either way I guess!
Todd, it fired up once after I bled it but then to my surprise never started again after that. That’s when I started on the fuel pump. I may have made the problem worse but it wasn’t starting either way I guess!
Steve Addy
Top Post Dawg
I too thought that the car had been running initially and then quit.
I reuse that plug as well Todd, every time. Never had a failure due to non-replacement.
Steve
burn_your_money
Veteran Member
At the shop we almost always reused them as well. Only in cases where the knife edge was really flattened would we install a new one. Bosch says it's one time use though.
Steve Addy
Top Post Dawg
VW says that about a lot of things too....yet in reality it's almost always reusable IMO. There are limits though.
IIRC there's an o-ring in there too isn't there?
Steve
Update on the pump: managed to shave off half of the points on a 12 point socket I have in order to fit the head plug. Torqued it (not very much) to 120nm as advised by InjectionPumps and the pump started firing fuel! I can’t believe adjusting a bolt that little had such a massive impact on the pump considering there’s already a seal in it!? Engine is getting fuel now but still not starting.. about to have a closer look at the glow plug circuit to see if it’s at fault.
Massive thanks for all your help guys, I was really at a loss with this and wouldn’t have thought that bolt needed anywhere near that amount of torque!
Massive thanks for all your help guys, I was really at a loss with this and wouldn’t have thought that bolt needed anywhere near that amount of torque!
KLXD
Top Post Dawg
Makes sense. The knife edge seals against full injection pressure. If it leaks you loose fuel to the injectors. Same with the small plug between the delivery valves. The o-ring only seals against case pressure.
I suppose the torque required to seal a new plug as quoted by the shop you talked to would be lower than on a used plug since the tip is already deformed? I dunno but every one of those I've tried to remove was TIGHT.
Good to hear you're getting somewhere.
I suppose the torque required to seal a new plug as quoted by the shop you talked to would be lower than on a used plug since the tip is already deformed? I dunno but every one of those I've tried to remove was TIGHT.
Good to hear you're getting somewhere.
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burn_your_money
Veteran Member
The o-ring only seals the case pressure (100ish psi max) but the knife edge seals the injection pressures. Since your knife edge was leaking, it may have eroded the metals and caused a channel that will never seal.
you should torque it to 100 ft-lbs. That’s the “spec” for used plugs we used.
you should torque it to 100 ft-lbs. That’s the “spec” for used plugs we used.
I torqued the head plug a bit more just to be sure and it seems to be working fine now, thanks for the advice! Had a closer look at the glow plug circuit and it seems that whatever clown had the car before me has fitted the wrong relay for the glow plugs. I’ve ordered the right one now, but until that arrives I got a mate to hold a wire between the battery and the glow plugs to heat them up for around 5 seconds before I turned the key. The engine instantly fired up when we did this but unfortunately the revs started climbing rapidly accompanied by a knocking sound so I turned it off. Any ideas for my new problem? 
I’ve read this can happen due to pump problems but I feel it’s unlikely after checking it over so thoroughly! Any help would once again be massively appreciated.
I’ve read this can happen due to pump problems but I feel it’s unlikely after checking it over so thoroughly! Any help would once again be massively appreciated.
burn_your_money
Veteran Member
Nice progress.
Back the main fuel screw out until the idle stabilizes. Then once it’s running, drive it and keep turning it up until it starts creeping up on its own and power/smoke is acceptable. Then use the idle adjuster to set the idle. It’s on the back of the pump, not the one that the throttle arm stops on. That one is for setting how quickly the RPMs drop.
Back the main fuel screw out until the idle stabilizes. Then once it’s running, drive it and keep turning it up until it starts creeping up on its own and power/smoke is acceptable. Then use the idle adjuster to set the idle. It’s on the back of the pump, not the one that the throttle arm stops on. That one is for setting how quickly the RPMs drop.
Todd, knocking from the engine. I didn’t have it started for more than a couple seconds to have a full listen but we all agreed that it was a much louder chapping than normal.
BYM, the fuel screw is in the same position as a tutorial I watched, could backing it off slightly stop it from red lining? Will give it a shot.
BYM, the fuel screw is in the same position as a tutorial I watched, could backing it off slightly stop it from red lining? Will give it a shot.
burn_your_money
Veteran Member
Each pump is unique in where the fuel screw goes, so yes. It will stop it from redlining. Assuming the issue is pump setup and not a damaged part in the pump.
Abacus
That helpful B4 guy
I am unfamiliar with these pumps but the TDI pump will increase in rpms if the QA stub is not seated in the sliding collar. Could it be similar?
Abacus, are you referring to the stub on the fulcrum lever (if that’s what they’re called in a tdi) that is moved by the throttle shaft? If so, yes that is located in the sliding collar. I had the lid off the pump the other day and pulled the fulcrum lever back and forth to check it was moving it.
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Quick update on this: I fitted my new glow plug relay and they are now fully functioning with the light on the dash also working to my surprise. Wound the max fuel screw way out and cracked the fuel lines at the injectors. Turned the engine over, wound it in a bit, turned the engine over etc etc until I could see fuel. I then tightened the fuel lines and with a few more small turns of the fuel screw (the engine needed a bit more than a dribble at the injectors) the engine is now idling nicely.
However, I have no throttle for some reason, even when I push the throttle arm to its stop, the revs don’t change, any ideas? Sure it’s something small I’ve not tweaked or something. The engine also seems to creep up the rev range when it’s idling for some reason?
Cheers!
However, I have no throttle for some reason, even when I push the throttle arm to its stop, the revs don’t change, any ideas? Sure it’s something small I’ve not tweaked or something. The engine also seems to creep up the rev range when it’s idling for some reason?
Cheers!
CasaEd, you could be right, I’ll have to take the lid off tomorrow and check that.
Todd, I remember making sure the throttle shaft was oriented in the anti-clockwise direction (the way it rotates when the throttle cable is pulled) when I put the lid back on but I’ll double check tomorrow!
Todd, I remember making sure the throttle shaft was oriented in the anti-clockwise direction (the way it rotates when the throttle cable is pulled) when I put the lid back on but I’ll double check tomorrow!
So I’ve now taken the lid off of the pump. Throttle shaft was oriented correctly, governor mechanism was still attached to the fulcrum lever and the fulcrum lever was still moving the collar on the plunger. Everything seems in order but no throttle still? Going to re-watch a few videos on the assembly/disassembly to see if I have missed any steps. I did notice the fulcrum lever travel seems quite limited by the governor sliding sleeve but unsure if this is normal or not?
Any further suggestions much appreciated cheers!
Any further suggestions much appreciated cheers!
burn_your_money
Veteran Member
are the governer weights moving in and out freely?
Try setting the throttle lever one tooth advanced and see if that helps.
the guys on VWdiesel.net might be more helpful since your engine isn’t a tdi. You need to search for the forum though, it’s a weird layout.
Try setting the throttle lever one tooth advanced and see if that helps.
the guys on VWdiesel.net might be more helpful since your engine isn’t a tdi. You need to search for the forum though, it’s a weird layout.
The governor weights appear to be in the right place. I’m unsure of how they’re supposed to operate when moved so I’ve linked a video below of me moving the sliding sleeve by hand for reference. A couple of the weights don’t always move outwards but I take it they will once the pump is sealed and operating? I’ll post on that forum too and see if anyone knows anything more.
drive.google.com
AAZ Fuel Pump pics - Google Drive
drive.google.com