Bongo Fury

Having read through all threads that I can find relating to my problems, without finding a succesful diagnosis, I've now decided to come out of the closet and post the question.

I recently changed the head and head gasket on my '96 2.5td because of high loss of coolant and large amounts of white smoke coming from the exhaust. Before the work she started and ran very well.

The symptons that I now have are:

1.Takes at least thirty seconds to start(I wait for the glow plug relay to de-energise before trying)
2.Once started, the engine has very little power and smokes a lot(black)
3.She warms up relatively quickly, up to 88C in about four to five miles.
4.Once warm, power is slightly better but still nowhere near as good as it was.
5.Quite a bit of black smoke on steady driving, and worse on accelaration.
6.Guzzling diesel. Used half a tank to do 100KM's

The work I did:

Replaced the following-
1.Complete Head/Head gasket
2.Water pump
3.Timing belt and tensioner
4.Glow plugs
5.Air filter
6.Fuel filter

Cleaned the banjo filter.

Had the injectors overhauled. Two were in very bad condition.

Fitted a low coolant and Mason temp alarm.

Blanked off the EGR.

Thoroughly bled the coolant system(don't want to change the head or gasket again!)

What I've already done or checked to try and diagnose the fault-
1. Had the injector lift pressures reduced to 110Bar to allow for any loss of performance in the fuel pump. She wouldn't start at all before I had this done.
2. Reinstated the EGR.
3. Checked the Winter pack exhaust valve was not seized in the shut position.
4. Cleaned the banjo filter again.
5. Checked prime on all four injectors by cracking the pipes whilst turning the engine.
6. Checked pressure coming into intake manifold raised when engine revs increased to confirm that turbo was spinning.
7. Checked all glow plugs were pulling current and heating on bench.
8. Filled up with fresh diesel.

I've written so much detail in the hope that I don't waste other peoples time asking me questions.

Any guidance would be greatfully received. Great forum.

Iestyn

Sorry to hear of your woes. Looks like you've already covered a lot of the possible options, but I would break it down into two key areas:

1) One of the new parts fitted is at fault
2) Something in the re-assembly process has gone wrong.

The only thing I can think of is have you double checked the valve clearances? If you used old valves in new head, did you you grind them in?

Have you checked the voltage is getting to the glow plug rail when you turn the key? you say you're waiting for the glow plug relay to de energise, how long are you waiting? with new glow plugs it should fire ok as soon as the light goes out.
Have you got any diesel leaks around the fuel pump? could be the fuel pupmp needs the seals doing (factsheet in the members area) or it needs a proper rebuild?
Is it getting sufficient air, have you cleaned/checked/replaced the air filter?
Have you checked it's sucking from the tank ok, could be the pick up strainer in the tank is paretially blocked if it's got really low?
If you reinstated the egr, did you check it was functioning coorectly before you did so? TBH removing/blanking it shouldn't have any negative effect on starting or running.
As Simon says, check & recheck everything that's been done.

Thanks to you both for such a quick response.

In answer:

I did check and then re-check the valve clearances once it had ran once. I forgot to grind the valves, it's been a few years since I did a head change on an engine!

The voltage to the glow plug rail is fine and stays there until the relay de-energises. The relay stays in for about twenty seconds, including when the light is on. I have noticed some diesel around the pump and engine block but assumed it was all as a result of me removing pipework and so on to check prime and air leaks. I think the pump seal is a good suggestion as I would imagine it's relatively easy and very inexpensive.

I've replaced the air filter and even started the engine with the air inlet duct from the filter housing removed but still smokes black.

I haven't checked the pick up strainer as I didn't know there was one. Where would I find it?

When I reinstated the egr I didn't check anything apart from doing the usual quality checks when putting things back together. Is there a way of carrying out a test. But I'm please that you say that blanking it off won't have a negative effect on the running. As you can imagine, I'm trying to get the engine back to where it was before I started working on it, within reason.

Another thought I had is regarding the lowering of the lift pressure of the injectors. Is there an absolute minimum that they can be set at. It would be nice to know what the pump is delivering to establish whether it's anywhere near the injector pressure or ready for retirement! The Bongo has done 176,000KM's after all.

Thanks again

Pick up strainer here - http://www.lushprojects.com/bongopartsm ... mgno=.html
42-113 on the tank sender in the upper left box for diesels.

Looks like this


sits within a few mm of the bottom of the tank. you could check it by running from a known clean fuel supply ie a can of diesel & a bit of hose.

As for the injector pressures, when new it should be 117.7bar, when reused 107.9bar according to workshop manual.

Sounds like the timing is out.
Check it again and check it against the manual.
If it is no longer drinking water, I would do a compression test on the head and see if they are all level in terms of pressure.
Overhauled injectors, were they done properly.

sounds like either the air intake is low/blocked,fuel mix wrong,or fuel just pouring in,to much fuel, mix again wrong.
could this be timing.

Your timing belt could be a "notch" out, which is 6 degrees of timing..... then the pump would not be timed properly....and could, I say could, have a big effect on running and fuel consumption......

Once you have her started and up to temp, you have rough running and black smoke.

Black smoke is unburnt fuel. This must be a compression or timing problem. Both relatively easy to check for - compression test and a re-check of the timing will give you an idea of what's going wrong.

If it's a compression issue then it could be genreal cylinder wear, but having just changed the head and running OK before that it's abvoiusly something to do with the work done. Either the head gasket isn't completely sealed or possibly a leaking valve issue - what clearance did you set for the tappetts?

The replacement head - was this new or 2nd hand? Has it been pressure tested?

I had a belt jump by a tooth on an Astra TDi a few years ago. Sounded like the engine had turned into a bag of spanners. Wouldn't start or run at all well. Didn't have enough power to actually drive anywhere. Smoke - like a James Bond smoke screen. When it went, there was a bang, and so much smoke I thought "Oh well, that's it scrapped then!" 2 days later it was running as sweetly as ever.

Presume you've done the usual checks to ensure that that little pipe that attaches to the turbo hasn't come adrift/unplugged? Its caused dramatic loss of power for others, though I don't recall it producing v. slow starts or black smoke.

Might be worth checking for loose/split hoses in the air intake/intercooler setup. As too much air is as bad as too little.

Wow-Thank you all for taking time to post.

I've printed off the responses and I'll try to answer all the points raised:

Timing-The cam to flywheeel marks were virtually spot on. Moving a tooth in either direction would have made it move away considerably. I did reach down onto the fuel pump pulley with a camera to take some photos of its timing mark and noticed that it was at the end of the marked area. There's a marked area of about ten to fifteen degrees that the pulley mark needs to be within. I felt that this was fine as I had no running issues pre-work. Maybe it needs moving toward the centre of this marked area. I'll check the cam/crank timing tomorrow morning an get back to you.
Injectors-They were overhauled by a company called "Direct diesel services" in Chester who are, apparently, very good. They were then checked by a diesel mechanic and pressures reduced to 110Bar.
Compression test-I'll ask the diesel mechanic to do a compression test for me as I don't have a gauge.
Air intake-I can't see anything fouling the air intak and I've started the engine with the duct removed from the filter housing an it still throws out the smoke.
The new head-This was a new head. Didn't pressure test it but also forgot to lap the valves, rushing again!
Head gasket not sealed-I followed the instructions on the factsheet and pulled the fasteners down with a calibrated torque wrench. I also cleaned the block up and removed any gasket shadow and had a straight edge on it before fitting the head.
Valve clearances-I gapped the valves to the measurements on the forum. It's written down at home but I'm in work at the moment. 0.4 and 0.8mm I think. Once I'd ran her I then rechecked and had to re-adjust three of the valves.
Turbo pipes-I've checked and double checked all pipework that was disturbed. The little pipe feeding the fuel pump boost gives a reasonable amount of pressure when the revs are raised.
Intercooler pipework-I'll check them tomorrow. I hadn't looked in that area as nothing was disturbed there, but there is a possibility that something may have come adrift or split whilst I was wrestling the pipework around the engine causing undue force at the front end.

Looks like another fun filled Saturday

Thanks again and have a nice Bank Holiday weekend all.

just another thought on timing, I had a diesel pump break up in December last year.....
It went off to Bell Hill , they also found that the Cambelt was a notch out and they said it would run that way but not 100%, hence my comment, now someone had "dialed" the diesel pump into that..... I did get quite a bit of black smoke when I pushed the Bongo, not a puff but a cloud then it cleared..... I get the odd puff these days
When the new pump was fitted and the cambelt replaced spot on and the Diesel pump "dialed" in too and it sits 1/2 way point in the adjustment span..... just a thought... Good luck with it

I'll have a look at the timing of all three pulleys tomorrow. I'm wondering whether she ran ok with badly set injectors masking the bad timing pre-work but now the injectors are set properly, the pump timing also needs to be right. Fingers crossed.
Thanks for the post. Ill keep you updated, providing the weathers kind to me!