Issue:Fuel Pump Resealed/No Start

As referenced, Fuel pump on a 2002 Auto MkIV. Top and bottom seals on main body and seals on side where the fuel lines are were replaced.

Body of pump was marked when the bolts were removed. Put together with marks aligned. Car won't start now though it was working before the pump was taken apart.

Tried the hammer mod to no avail. There was a bit of fuel leaking when we tried the hammer mod so we need to purge the air again.

Can't fix the IQ since the car has to be warmed up from what I've read. IQ on VCDS is at 0.0.

What is this telling me and how do we fix the issue to get this daily driver started?

Start with purging the air in the lines from the IP to the injectors.

If you are getting fuel squirting out, then it's a matter of adjusting the IP to get in the ball park to start the car. If you did the reseal properly, you would have marked the outside of the pump with a reference mark so you were close enough to get it to fire when you reassembled. I assume that's what you meant. That should have been close enough so move it to that mark.

If not, then you will need to keep adjusting the top head until you have it dialed in manually. I don't think you will get a proper IQ reading until the engine fires up. Also, check to make sure you have sufficient voltage to get the engine to turn over fast enough. There is a minimum threshold of cranking RPM before the ECU will let the engine start.

Thank you for your response. We have a battery charger hooked to the battery. So its turning over well.

Reference marks on outside of pump, check!
We will purge the air again.

Now we saw air in the clear part of the hose between filter and IP. We'll have to purge that and then see if there's air from the IP to the injectors?? I'll have to look (search) how to do that.

You prime the IP first. As long as you are drawing fuel from the output side that means the pump is full of fuel and you can stop. A bubble or two or three on the clear line is not a problem. Once you have the prime, then you can loosen the injector lines to allow them to bleed the air, closing them immediately when you see fuel coming out.

If you see fuel coming out of them the engine tries to starts up, rough usually. I make it a point to shut off the motor and close off the injector nuts instead of having fuel spraying all over the place. The motor will start right up after you get them done getting smoother as the air is completely purged.

Thank you for clarifying. That is an immense help!!

Let me clarify further on priming the injectors. You do that while the engine is being cranked over.

We have reprimed the pump several times due to taking the top off to make sure that shaft was in its position inside the pump. Unfortunately, you can't ever be sure since you can't see the shaft when placing the top in place.

Bottom line is that there is no joy yet. Injectors have fluid coming out, but not spraying out. More like a small flood out the top when loosened, but all have diesel coming out. This may be a symptom of an issue. There is absolutely NO high pressure spraying going on as I've read in other posts that describe bleeding the injectors. Its a small flood just seeping out the top of the injector nut.

Two points of interest...alternator was replaced before the IP job and the car started right off. Due to alternator having been drowned in diesel. Anyway, the day before the IP job, the car was starting.

I've looked at the anti shudder valve and it moves, albeit stiffly. Second, there is no glow plug symbol showing but this seems to have been the case before the job.

Car hooked to charger and battery is busy charging.

What am I missing???

Rechtsverdreher said:

Bottom line is that there is no joy yet. Injectors have fluid coming out, but not spraying out. More like a small flood out the top when loosened, but all have diesel coming out. This may be a symptom of an issue. There is absolutely NO high pressure spraying going on as I've read in other posts that describe bleeding the injectors. Its a small flood just seeping out the top of the injector nut.

Two points of interest...alternator was replaced before the IP job and the car started right off. Due to alternator having been drowned in diesel. Anyway, the day before the IP job, the car was starting.

I've looked at the anti shudder valve and it moves, albeit stiffly. Second, there is no glow plug symbol showing but this seems to have been the case before the job.

Car hooked to charger and battery is busy charging.

What am I missing???

Click to expand...

Did you remove the pump for this or do all the work in the car?
Depending on how much you loosen the injector lines you might not get a strong squirt, just a dribble out.

I can't see the alternator change doing anything unless it has a shorted diode in it.
Does the tach in the dash indicate the RPM's while your cranking? How much? Some do not show it.

How old is the battery that you are keeping it on charge?
If it's a 10 amp (normal) charger it should have the battery full in a few hours.
Maybe shut the charger while cranking to eliminate it as the problem.
Last, disconnect the ASV hose and make sure the valve is open.
Once the motor is running you can reconnect it.

Pump stayed in car. I do not have the tools to to a timing belt.

The reference to the alternator was simply to say that once the alternator was installed (due to the old one being covered in diesel fuel) the car started right up, immediately before the IP was sealed.

I don't know what the tach is doing but will check it in the morning.

Battery is fairly new but seems to slow down after cranking for a bit. That's why we left the charger on it. Its out of the car right now being charged.

Will do on the ASV hose.

Rechtsverdreher said:

Top and bottom seals on main body and seals on side where the fuel lines are were replaced.

Click to expand...

Do you mean the head o-ring? Or just the copper washers?

Two large gaskets on main body. Actually need to replace one now since moving the head around seems to have damaged it a bit. This is extremely frustrating and the car is a daily driver for a friend of my sons...(superfluous information, I know)

OK so you only replaced 2 seals? The black ones with ribs on them that go above and below the quantity adjuster?

Correct and the circular one on the side facing the driver side with the injector lines coming out.

You didn't pull the head completely off did you?

No glow plug light? Check relay 109.

Ok, since you had the head out of the pump we are dealing with a different can of worms than if you had just done the QA seals.

Can you describe the steps you used to replace that seal please?

Take the 12mm bolt out of the center of the head (all 4 injection lines surround it) and find something that is about 3" long that will fit inside the hole. It will need to be fairly thin. Push it in until it bottoms out on the end of the plunger. Have someone rotate the engine while you hold LIGHT pressure on the end of it. You should see it moving in and out about 3-5mm, twice per crank rotation. Make sure to only insert it straight in. Solid copper wire would be a good choice. You do not need to remove the injection lines to do this. If it passes this test you probably did that seal correctly.

burn_your_money said:

You should see it moving in and out about 3-5mm, twice per crank rotation. Make sure to only insert it straight in. Solid copper wire would be a good choice. You do not need to remove the injection lines to do this. If it passes this test you probably did that seal correctly.

Click to expand...

I remember checking the pump timing on the 1.5 & 1.6 diesels with a dial indicator through that hole.
What happens if you take the entire head out?

If the head is on the side where the injectors hook up (burn-your-money references it as the "head" if I interpret correctly, then it did not need to come all the way out if I recall from reading the directions. All kinds of dire things are promised if that happens I believe.

My son and friend who owns the car did the job with the large circular o-ring and the two gaskets on top of the pump. I'm not saying this was done correctly but my son is fairly anal so he was following the Dieselgeek directions very carefully.

Will follow directions with copper wire to test the o-ring replacement.

By the way, turn the crank on the engine, don't turn over with key, right? Further, now pump will need to be reprimed, correct?

Thank you!

If you take the entire head out there's a shim in the center that almost certainly will drop. Cam plate may fall out of place too.

Yes, if you pull the center plug to test the plunger movement you'll need to reprime.

They didn't pull the entire head out. Followed the Dieselgeek directions. they also tested that center bolt method before doing the job as described above and per the directions from Dieselgeek. I told him he now needs to do it at this point as well.

Good to know about prime, thank you for confirming. We are becoming quite adept at that.

Correct, turn it over by hand. I like to jack up 1 wheel and put it in 4th gear and turn the engine by turning the tire. Whatever is easiest though.

The steel part of the pump is referred to as the head with the plunger/rotor being inside it (10 or 11mm). As you said, lots of things go wrong if it's not done properly. The shim can fall out, the camplate can fall out which then releases all the rollers. The return springs and their holders (forget the proper term) can fall out. Worst case is you snap the plunger/rotor. I don't do this seal on the engine for this reason. I know many have, but I won't risk it.

You probably don't need to reprime after this procedure. You'll lose minimal fuel.

Well, that's an interesting way to turn the engine. We'll give that a try, weather permitting. Its in the 20's (F) today so may not get out there, though I'm sure its nothing in your neck of the woods.

We'll have to reprime in any case as of the gaskets seems to be coming apart, the lower one, moving the top of the pump too much, I guess. We will also need to reprime fuel filter since that hasn't been done.

If I lift up the car on an automatic and turn the wheel, what gear should the vehicle be in or should it be in neutral? (Cold out there!)

You can't rotate the motor by rotating a wheel of an auto trans.

Well, we primed the pump, the filter and the injectors. Got a new battery, tried a new 109 relay but no joy on the anything showing up on on the dash in terms the glow plugs.

Car will start barely with a gasoline soaked rag held over the intake where the air hose attaches.

This thing just does not want to start.

Does it keep running if you remove the rag? If not did you bleed injectors while using the gas?

If you've got it fully bled to the injectors try hammering it again. Those two things both have to be right after resealing.

INjectors bled. Does not keep running after rag is removed.

Right now, hammering does no good except causes leaks. Also, new issue is that there is no diesel at the injectors now. Further, opened up the top again to make sure the pin was placed correctly in its slot. Believe it is. Still no joy.

Bump is bled to point where there is solid line of fluid!

I wanted to close this one out. Thank you for all the help trying to diagnose this.

What ended up happening is that I called a friend who came over. He knows his stuff. Immediately said that the o-ring on the pump head must have been installed incorrectly leading to internal damage. Some replies indicated this as well.

We swapped out the pump with attendant timing belt work, timing the motor and after we got it bled, it started real strong. Due to the attention paid to timing, it was right on the money with VCDS.

I've learned a lot on this job but still would be nervous about a timing belt change! Only problem was loosening the sprocket on the cam so had to delay work for a week until the proper tool came in. None of the fixes I searched for cam sprocket removal worked. Proper tool was the ticket.

Thank you again for al the help received!!!

Glad you got it going.

I don't know what you could have done to cause this. If the pump piston were broken by tightening the head bolts unevenly you shouldn't have gotten fuel to the injectors.

You going to open it up to see what broke?

Did you loosen the big three sided plug on the end between the fuel lines?

KLXD said:

Glad you got it going.

I don't know what you could have done to cause this. If the pump piston were broken by tightening the head bolts unevenly you shouldn't have gotten fuel to the injectors.

You going to open it up to see what broke?

Did you loosen the big three sided plug on the end between the fuel lines?

Click to expand...

The fuel coming out the injectors was probably just fuel pushed through by the low pressure pump.