2001 Caddy Van - ALH Engine - Lacking Power After Timing/Rebuild

RobSharky

Active member
Joined
Mar 24, 2009
Location
Inverness, Scotland.
TDI
2001 Caddy Van
Hello everyone,

I recently rebuilt my ALH engine (conrod failure due to hydraulic lock) and fired it up last week:

http://www.youtube.com/watch?v=-Ub9fTpumVY

The engine itself sits perfectly at idle and I can drive it up to about 40mph without problem (Water/Oil bgood) but it lacks power from around 2000rpm onwards under normal load?

The turbo is a rebuilt unit so I don't think the issue is there so I can only assume it's fuel pump related? I've no black smoke out the back which leads me to believe the fuel/air ration is all good but that it's just not getting enough furthur up the rev range - engine revs freely enough above the 2000rpm when not under load.

Does someone have a diagram of the EGR/Turbo system on the ALH so I cna check all is well with the three control solenoids?

I do have VAGCom but the laptop isn't here this weekend so I've not been able to take readings as of yet for advance/retardation of the pump.

Thoughts on what I should check? Would the fuel pump being too far advanced/retarded cause power issues like this?
 

Evan_schulte

Veteran Member
Joined
Apr 14, 2009
Location
Lake Geneva Wisconsin
TDI
1997 Jetta TDI
Usually there is a diagram on the front "ledge" when you open the hood. There is a vacuum system diagram right there on mine. Maybe not on yours. I'm not 100% sure.
 

RobSharky

Active member
Joined
Mar 24, 2009
Location
Inverness, Scotland.
TDI
2001 Caddy Van
Test drove the van with the MAF disconnected and it is much more powerful and will pull up to 60mph a lot better.

Can I check the MAF with a multi-meter? £140 for a new one and I don't really want to waste that if it's just the plug?
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Try cleaning the MAF. They do sell MAF cleaner here in the US for $5 a can. Or you can use Starter Fluid for $2.50 a can. They smell remarkably the same...

Spray the element and use a cotton swab to clean the more stuck on black. If you have opportunity to check the MAF before cleaning and after, you'll probably see a comparative high reading in the Engine module/ block 4? somewhere around there... it will show a requested and actual MAF reading.

They should be fairly close after cleaning. One I cleaned yesterday was originally reading 590 actual 260 requested. When I was done, it read 290 actual... very reasonably close.

I've got new Bosch MAFs for $98 USD. 140 quid??? I think I could send you one economically, if you really needed it.
 

RobSharky

Active member
Joined
Mar 24, 2009
Location
Inverness, Scotland.
TDI
2001 Caddy Van
Franko6 said:
Try cleaning the MAF. They do sell MAF cleaner here in the US for $5 a can. Or you can use Starter Fluid for $2.50 a can. They smell remarkably the same...

Spray the element and use a cotton swab to clean the more stuck on black. If you have opportunity to check the MAF before cleaning and after, you'll probably see a comparative high reading in the Engine module/ block 4? somewhere around there... it will show a requested and actual MAF reading.

They should be fairly close after cleaning. One I cleaned yesterday was originally reading 590 actual 260 requested. When I was done, it read 290 actual... very reasonably close.

I've got new Bosch MAFs for $98 USD. 140 quid??? I think I could send you one economically, if you really needed it.
Hello Franko6, will us some WD40 and compressed air on it tonight. The previous owner ran the engine without an air filter for a time, don't ask why, but generally seemed to take poor care of the engine and subsequently the MAF was full of debris in the mesh so it doesn't surprise me it's not in a good working condition. I've been told that the VW dealership do an exchange, like on the water pump units, so I will find out a price tomorrow.

The vehicle isn't road legal as of yet but would the lack of MAF cause any issues with excessive smoke/over fueling? That's the only thing with our MOT road testing that I can see an issue with while I source a replacement - id like to put it in for a test this week.
 
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