1993 AAZ won't fire. Help

[haybayian]

I thought I had done everything , timing etc, by the book (s) yet my remanufactured AAZ refuses to fire...not a burp! Cranking seems to be ok, the fuel reaches the IP and the injectors. I have loosened the hard lines bolt to the  injectors until the air bubbles stopped and retightened them.

Now I have redone (several times) the static fuel timing, starting from checking TDC position (cam, pump crank).  The IP plunger travel reads .95  to 1.00 mm consistently. I take that for this engine the value should be .80 to .85 mm. Is this why the engine refuses to fire?

There are quite many things I don't know about this engine. It was assembled by a professional remanufacturing shop from two engines and the desk guy was vague as to their actual identity. The rebuilt engine was delivered to me with no turbo but a turbo type exhaust  manifold. Then The IP was rebuilt by Giles and I don't know what he did and whether his performance  mods could alter the plunger's travel. My question:

Should I rotate the pump?

Thanks

[Patrick]

You sure the slot in the cam is up instead of down? Might be out 180 degrees...............

other than that, maybe check and make sure you've got good compression, wouldn't be the first time a shop messed up.

[bert]

your glow plugs working?
Bert

[Vincent Waldon]

0.95mm is perfect for an AAZ with a Giles pump, so that's not it unfortunately.

You've confirmed you have fuel to the injectors, so that means you have 12V to the solenoid.

Is the cam timing bang on ??   Both lobes for #1 up, cam locked, engine at TDC ?

Injectors new ?  Been sitting ??  

And finally, yes, a compression test is probably the fastest way to narrow things down... fuel + compression + timing should equal running.

[haybayian]

Thanks  Guys,
I am cranking this mill with no   functional glow plugs assuming that with 20 degree C+  temperature outside this should not be a problem (i.e on my boat neither my Volvo nor the Detroit have glow plugs). The  AAZ's injectors are new. The timing yes both lobes up, pump  and cam setting tools in place with flywheel on TDC.
I will buy a compression test tool tomorrow and check these. My engine runs out of guarranty in June so if there is some mechanical problem I have to find out now.

I was wondering if in the process of rebuilding this engine (out of two VW diesels) the shop may not have fitted the wrong camshaft.  Considering that the only test they run before releasing the engine is a quick run at 500 rpm they may not notice a cam with a different profile....Could this be a clue?

Thanks again for your time.

Haybayian.

[bert]

AAZ will not start without glow plugs,mine dont,or it will after turning over for 2 minutes on the starter,put a live to them and try it then
Bert

[Vincent Waldon]

I was wondering if in the process of rebuilding this engine (out of two VW diesels) the shop may not have fitted the wrong camshaft.  Considering that the only test they run before releasing the engine is a quick run at 500 rpm they may not notice a cam with a different profile....Could this be a clue?

My understanding of VW diesel cam profiles is that they are very similar between engines (the NA and turbo 1.6 are the exact same, for example) so my guess would be that even with the "wrong" cam it should still start and run.... the diesel engine is also not as sensitive to cam profiles as a gasser is.

[jimfoo]

My rebuilt AAZ started fine in warm temps without glowplugs. No water in your tank?

[haybayian]

My rebuilt AAZ started fine in warm temps without glowplugs. No water in your tank?

Thanks, I will check that too. I will also look at the battery and the starter. The thing cranks but it does not sound overly enthusiastic. So the combined effect of no glow plugs and a slow starter may be it.

Haybayian

[Dr. Diesel]

check that the flywheel is installed correctly. it is possible to mount them wrong, despite the two locating studs. Loosen the glowplug or injector out of #1 cylinder, and leave it hanging by a couple threads. turn the engine by hand quick enough to hear the hiss of compression blowing past the plug/injector threads and stop turning when the hiss stops. If you go too far, it'll suck air back in, so listen carefully for the point between outhiss and inhiss. (two more words for my dictionary!! :lol: ) When you find that point, you're pretty safe to assume TDC compression. Now look at your flywheel for markings. should be close at this point. Depending on your clutch (either 6 or 9 bolt) it could be 60° or 40° out of whack, if it's misplaced by only one bolt hole. Without some heavy duty thinking, I'd bet that it's possible to have the engine that far out of timing and still have piston/valve clearance. I've seen a 1.6L running once with a cam that slipped almost 180° while running. Remarkably, it still ran decently.

Keep in mind (note well, other dieselites!) there are two marks on many flywheels. A cast in dimple, or 'O' and a machined notch. The notch is the timing-light mark for whatever engine the flywheel was originally installed on. The cast 'O' dimple in all cases represents TDC. Always use the 'O'. If you time your engine to the machined notch, it might be outside of useable parameters.

[haybayian]

Hi Dr Diesel and other dieselites,

My engine  finaly roared this morning. What was needed  was only  more juice from the battery. So I upgraded the battery to higher CA and got myself a gauge 1 battery-to-starter cable . At the second push on the button she fired happily. I am glad to report that both the Giles pump and the remanufactured AAZ Cross Town Motor from Toronto are performing very well. I was even surprised to see no smoke coming out of the exhaust.

Thanks to all of you who have advised me.
Haybayian