ALH in firetruck for pump motor

[vas]

Have a late 90s 1.9tdi to drive the fire pump on my engine. Had a head gasket issue and ever since it was replaced, been experiencing extremely hard starting and unable to get it to full rpms. The few mechanics we have taken it to just want to throw parts at it.
Any shop recommended in Mesa, Arizona. Tia.

 

[oilhammer]

Can you post a few pics? It should have some form of OBD if it is a TDI Industrial engine. What engine code is it? What was the reason for the head gasket? Which replacement gasket was used? How was the timing set?

 

[greengeeker]

What Brian is hinting at: removal of head really opens up a can of worms for someone that doesn't know these engines. They could have put in the wrong thickness of head gasket, incorrect cam to crank timing, incorrect injection timing, etc.

For what it's worth, head gasket failures are exceedingly rare on these motors. If it indeed had issues with head gasket sealing, you have bigger issues requiring more than just a new gasket.

 

[vas]

As far as i know, its the industrial 1.9T. No obd port on engine.
Gasket was done by an outfit we are new to. Took them 3 weeks. I do remember them having issues with getting the gasket.
Im just trying to find a good mechanic thah can look at and fix it.
How do I post pics?

 

[oilhammer]

You can cut 'n paste pics here now.

Is the engine computer controlled?

 

[vas]

No computer control. Mechanical fuel pump with electric lift pump.
ADE code

 

[vas]

20220922_124516.jpg

drive.google.com

 

[oilhammer]

OK, ADE code, that's more like an AAZ, not an ALH. It is not even a TDI, it is a prechamber engine. It is a 75hp, old style engine (028), mechanical injection pump, and depending on application has several choices.

So, the engine is a VAG Industrial unit, now whose pump assembly is it? There should be some sort of information on that somewhere.

In any event, the previous questions remain:

Why the head gasket?

Which one, and how was that determined?

How was the timing set up?

What was the condition of the head?

How are the injectors?

Does the engine smoke?

Does the glow system work?

Has the pump been messed with?

 

[d24tdi]

To add another one: has anyone (either you or the shop that did the work) ever used ether to try to start it?

It's a common temptation for folks who become extremely frustrated on these engines when they are working without sufficient understanding/information/special tools and trying to get it to fire when the timing is off and/or fuel system not primed. Seem to see it especially often on the old mechanical motors which are even more unforgiving of timing mistakes than computerized TDIs are. It can do everything from explode the glow plug tips, to blow headgasket, crack pistons, bend rods or cranks, etc. The risk is often greatest is when one of these VW engines ends up at an heavy equipment type shop where a can of starting fluid is almost always within arm's reach. Too easy to grab it and give a shot. Most folks know deep down that it is not the answer, but when you've been fighting it all week, you can start to lose your grip....

That said, my money would be on cam and/or IP timing simply not set right. That would account for the hard starting and poor running/output.

FWIW, while headgasket failure is rare on the direct injected motors it is not unusual on the old prechamber motors.... but all the same it still happens for a reason, not randomly, so answering OH's "why the headgasket" question is still necessary. The prechamber setup pushes so much heat into the head that in the event of any cooling system issue, temps run out of control more quickly and the operator has less time to get it shut down. But it still requires something to provoke it.

 

[oilhammer]

Except that, these later prechamber engines use MLS head gaskets, just like the DI engines, and are much, much less prone to any cylinder head gasket failure.

 

[d24tdi]

Except that, these later prechamber engines use MLS head gaskets, just like the DI engines, and are much, much less prone to any cylinder head gasket failure.

I wasn't sure when they made the switch but had heard some of the later ones (like AAZ) had MLS from the factory. I guess it would make sense that by the late '90s they would have them.

If so, that just adds even more emphasis to the question of what provoked the HG failure.

Usually industrial equipment like this is pretty well outfitted with warning systems (and often also automatic shutdown) for low coolant level or excess temperature, plus they usually seem to run in relatively steady state conditions at something less than full load or speed, at least by automotive standards where the governor allows full fuel delivery over 4k rpm. So I think that the industrial application would further help the chances for survival unless something has gone pretty far wrong.

Headgasket failure from excessively advanced static timing (ie mark and pray tb job) on the old prechamber engines is not unheard of so that could be a possible cause, depending on the engine's maintenance history, if no other obvious explanation shows up.