Why does my diesel smoke?!!!!

sesweller · Post by **sesweller** » Mon May 10, 2010 10:12 pm

I bought a 1984 diesel rabbit 1.6. i thought it was goin to be a easy fix but not. i found out my head a cracked and warped. so i bought a used head which is good. got it to run. but smoking white smoke ready bad it that all it does. would anyone know why it would be doing that? i was thinking it got really hot one time and the rings a stuck?

i need help!!!!!

82vdub · Post by **82vdub** » Mon May 10, 2010 10:44 pm

Welcome to the forum. Typically, whitish smoke from a diesel is unburned diesel fuel. The two likely culprets of this is low compression, or retarded timing. I would start with advancing the timing on the injector pump (IP), which is rotating it towards the head. If you're wrenching on your own VW and don't own a Bentley repair manual, get one fast. You'll need it to properly repair one of these cars. How did you set the injector pump timing when you replaced the head and did you set it up per the Bentley manual?

Make sure you also have clear lines going to and from the injector pump (and change the fuel filter no matter if the previous owner said they changed it). Watch for bubbles in the lines. This can also lead to poor combustion and whitish smoke, but typically it will run pretty poorly at the same time (you didn't mention this).

Quantum-man · Post by **Quantum-man** » Tue May 11, 2010 4:29 am

Timing 180 deg out?

sesweller · Post by **sesweller** » Tue May 11, 2010 4:48 pm

How do you set the injection pump? like what marks do i need to line up? I lined up the injection pump pulley (the dot on the pulley with the mark on the pump, which was a straight line) is this the proper way to set the timing on the injection pump?

Quantum-man · Post by **Quantum-man** » Tue May 11, 2010 5:22 pm

sesweller wrote:How do you set the injection pump? like what marks do i need to line up? I lined up the injection pump pulley (the dot on the pulley with the mark on the pump, which was a straight line) is this the proper way to set the timing on the injection pump?

If there was any doubt, I'd loosen #1 injector fuel line, at the injector and whilst looking down oil filler cap onto #1 cam lobes, turn engine over with a spanner [wrench?]

and watch for the fuel droplet... {{ignition on, g/p power disconnected [pulling relay easiest]}}

82vdub · Post by **82vdub** » Tue May 11, 2010 5:39 pm

Here's a link to Vince's site that explains in great detail how to properly time these engines: http://vincewaldon.com/index.php?option ... &Itemid=28

A note worth mentioning: You can mess up the timing of the injector pump and not really hurt anything (it will run, won't run, run bad, run ok, etc), but if you mess up the timing between the crank and the camshaft, you have the chance of damaging the valves and head. A key point is that if you touch the timing belt on one of these engines (they're interference engines meaning that there's not enough clearance between the pistons and valves) is that you turn the engine over by a wrench on the crank bolt at least two full revolutions before you turn the engine over with a key. Any piston to valve interference will easily be found and allow you to correct it, before you use the starter and mash the valves into the pistons potentially causing damage.

sesweller · Post by **sesweller** » Tue May 11, 2010 7:24 pm

do you have to have a timing tool to time the injection pump? or can you just line up the mark on everything??????? that all i need to know thank

Quantum-man · Post by **Quantum-man** » Tue May 11, 2010 8:20 pm

sesweller wrote:do you have to have a timing tool to time the injection pump? or can you just line up the mark on everything??????? that all i need to know thank

If you are sure that you are injecting at #1 TDC on compression, then setting pump by the marks is fine.
You may want to swing the pump either side to find best running position.
You must ensure that you use a good fit bar & feeler gauges to set cam to TDC on crank though

Vincent Waldon · Post by **Vincent Waldon** » Tue May 11, 2010 8:45 pm

sesweller wrote:do you have to have a timing tool to time the injection pump? or can you just line up the mark on everything??????? that all i need to know thank

There aren't any "marks" to line up on the pump... it can be in different positions due to the elongated mounting holes. The dial indicator is how you know it's rotated properly... to the 1/1000th of an inch.

It's certainly possible to tune by ear... especially with experience...but if you're getting lots of white smoke something is probably a long way out of wack and the quickest way to figure things out IMHO is to measure what you're doing... the complete kit of all the tools needed is generally under 100 bucks on eBay. :

Note the "IMHO"... other folks time by ear... my point is that if you're new to diesels and facing serious white smoke the dial indicator will help you sort it out in minutes... every time... no other experience required.

sesweller · Post by **sesweller** » Tue May 11, 2010 9:23 pm

this is my first diesel car. i dont understand why some people say you can time the pump without tools and then others say you have to hav tools???? will a diesel run no matter wat the time is on the pump?

82vdub · Post by **82vdub** » Tue May 11, 2010 9:53 pm

sesweller wrote:this is my first diesel car. i dont understand why some people say you can time the pump without tools and then others say you have to hav tools???? will a diesel run no matter wat the time is on the pump?

As some that have posted here have found out, these engines have run when the injector pumps are 180 degrees out of time and/or quite off time. The ease at which it starts though isn't necessarily all that great if the timing isn't right. However, "running" and being able to drive the car down the highway "running" isn't the same thing. If you line up the marks as directed in the proper procedure to set the "base" injector pump timing, at this stage, the engine will likely run pretty decently. But, whether the timing is too far advanced (really loud engine knocking sound) or really retarded timing (white smoke) is not known until you run the engine. You don't "have" to have a dial indicator to time these. I've changed timing belts and put everything back together without a dial gauge and it ran good so I left it. I've also timed it to the dial gauge, and I've also timed it to the dial gauge and then adjusted the timing from there.

I had a friend in high school that could time his car by ear, and he was really good at it (Chevy V8). He'd time it then run it by my house to see how far off he was according to the timing light. He was typically within a degree or two either way. I'd bet to this day he still doesn't own a timing light. No need to if your that good at it.

From what you had posted earlier on your initial setting, you assumed that the marks on sprockets etc was what you needed to set something to line up with, in essense guessing at what timing setting you set the pump at. It could be really close to what it needs to be set at (clearly off because of the potential white smoke cause) or it could be way off. I'd say to start over and set per the procedure outlined on Vince's site, skipping the dial gauge setting if you don't want to get a dial gauge. Fire up the car and see how it runs and if you need to, adjust the timing from there. Order a Bentley repair manual if you intend to keep this car and work on it yourself.

sesweller · Post by **sesweller** » Tue May 11, 2010 11:02 pm

to retard that time on the pump do i turn it count clockwise? how much would you say a notch or two or wat?

Josh · Post by **Josh** » Wed May 12, 2010 12:33 am

What can bubbles in the return fuel line indicate? I saw this recently when doing a can of Diesel Purge.

Post by **Fatmobile** » Wed May 12, 2010 12:36 am

Turn the top of the pump toward the head to advance timing.
Hard to tell how much it's off,
Have you checked to make sure it's not 180 out?
Crank at TDC, Cam lobes on cylinder 1 pointing up(ish),
while the injection pump sprocket timing mark is in line(ish) with the line on the pump body.

sesweller · Post by **sesweller** » Wed May 12, 2010 8:02 am

so when you mean turn the top of the pump. you mean loosen the two bolt and move it towards the head? so wat way do i want to move the pump when its blowing white smoke? towards the head or the front of the car? thanks alot guy!!