Some newbie syncro advice

[bikermike87]

Hey everyone,

(scroll down to the summary if you don’t want me long winded story!)
I managed to scoop a new 2.1dj engine with only 15k miles for a pretty good price. Test drove the engine in the original van and it drove soooo well and then engine sounded spot on.

I had to get the engine in pretty quick and I don't have any workshop space, so I paid to get it changed over with a very trusted VW mechanic.

Picked the van up and what a difference. It pulls like a train and I was told by the guy it was the fastest /smoothest 2.1dj he had seen in a long time.

The next day, I took my van out to show the new engine off to the girlfriend and it started making very loud banging noises from the exhaust and then cut out.

The engine was running on 98octain but was set to 95 by the mechanic. I thought, maybe it was because of the 98octain that was left in

Recovery guy came and then it started up fine and played nice for a couple of weeks (I had put 95 in and run it most days)

I left the van for over a week and it just wouldn't start, new battery (needed one anyway) and it still struggled. I had to keep the key turned to get it to fire up, then it sounded like a backfire and flames from the exhaust.
It went smooth and then ran fine. I used it most days and the fault had gone, until I left it for over a week again.

So, any ideas? Could it be related to the exhaust, possibly when changing it over?

The engine is running perfect when used often, I'm getting 28mpg compared to 17.5 (previously)

So quick summary:

Engine changed
Timing changed to 5 degrees
Runs smooth
Leave it over a week and it struggles to start and then backfires (flames out of the exhaust)
Keep it revved over 1000rpm for a few minutes and it seems to be fine.
Van runs smooth, returns good mpg and is a joy to drive

I knew nothing about mechanics when I bought my syncro. I know a little bit more now, but I’m concerned I don’t know enough to own one. My van has had a new VC, gearbox done by syncrospares, brake disks, fuel lines and everything else major. It’s just these little niggly bits that really frustrate me and I want to be able to use this van as my main vehicle so I can sell everything else I have (i might be moving to somewhere with 1 parking space).

Planning on using this thread to keep me motivated on the finished product. There is nothing I want more than to visit friends in Norway and Sweden in the van, I just want more confidence about my ability and the vans reliability!

Any help advice on syncro ownership is welcomed. I don’t off road the van, just go across muddy fields and visit the beach and look forward to snow.

Here’s a pick of my van anyway, just in case you have noticed it before and to track my changes.

[PetenAli]

Hi mike. Good to hear from you. On my i phone at present so will do longer answer when I get home. First thing I would do is get it timed to 10 degrees BTDC and start using 98 ron fuel. Also might be worth changing fuel filter.

Catch up later,

Pete

[toomanytoys]

Off top of my head....

Sounds like overfueling on cold starts, or weeping injector dripping fuel in while stood.. when it does it, is the exhaust black and sooty?? (prob difficult to tell with condensation tho)

Might be worth checking fuel pressure being delivered.. although good mpg suggests this is prob ok...

Might be worth checking valve preloads.. with each pot at tdc, reset the valve preload to 1/2 (half) a turn max..

[syncrosimon]

If it is banging like a backfire I would suspect that it is ignition. Take the plugs out and examine the colour after a period of backfire. You may be able to tell an individual cylinder fault ie plug, wire, dizzy etc from one plug being darker than another.

If she is backfire and running poorly on start up, wet the exhausts and see which one remains cold, the good cylinders will heat the water off quickly.

This assumes it is one cylinder giving you gip.

Simon.

[silverbullet]

I'll plump for an ignition fault first if it needs lots of cranking and revving whencold (plug leads breaking down, poor connections at TCI, partial break/high resistance in distributor wiring etc.) and it's relatively quick/cheap to check for these along with plugs helping to identify a leaky injector as per both Simon's advice.

Second would be lack of cold start function so maybe temp sender(s) gone west, ecu doesn't know the engine is cold? Is it OK once warmed up?

See KarlT's thread for his ongoing DJ starting woes, the same advice has been given there and more besides. Best of luck!

[bikermike87]

Thanks for all the advice guys,

My knowledge is very limited, so I will refer to the haynes manual for most of the suggestions and I think I should buy myself the bentley manual...

It's just annoying as it only happens if my van has been stood still for over a week. If i use it once or twice a week, it starts and runs first time, everytime

I do tend to read every thread in this forum so I can pick up some advice. I don't tend to post because I'm in no position to offer advice on very techy things, but hey I'm learning more than I did in school

I'm going to progress the thread further once I get this niggling bit out of the way and my van returns to it's bullet proof self again!
I'm looking for advice on future changes, dare I say it, cutting a hole in a panel van

[jes*b]

Nice ride. Panel vans are like flares - always come back in fashion if you wait long enough. At the very least swap the door for a cut one but keep the door! I'm trying to find an uncut Lhd slider in good nick, not easy. Good luck with the engine

[Syncrobaz]

I had a similar problem on my mv, could of sworn it was fuel starvation. Changed the fuel filter,no joy! In desperation tried a set of h.t. leads, perfect !!!



May be worth a try ???

[PetenAli]

Hi Again Mike,

I'm not going to add to the learned contributions above about your starting problem but... I do think its a false economy to run your engine on 95ron and 5 degrees BTDC. See this thread started by Syncrosimon who knows a lot about these engines and it includes contributions from Tencentlife who is the main man in the Sates and regularly posts on the Samba forum: https://club8090.co.uk/forum/viewtopic.php?f=4&t=85055" onclick="window.open(this.href);return false;

I'll watch your thread with interest to see how it goes!

(Also thought I'd mention - we were camped next to you at Druridge Bay - did you get home with that clacking CV joint?)

[Jim Hunter]

I am almost sure that you are dealing with a faulty cold start valve.

Cheers

Jim

[bikermike87]

Hi Again Mike,

I'm not going to add to the learned contributions above about your starting problem but... I do think its a false economy to run your engine on 95ron and 5 degrees BTDC. See this thread started by Syncrosimon who knows a lot about these engines and it includes contributions from Tencentlife who is the main man in the Sates and regularly posts on the Samba forum: https://club8090.co.uk/forum/viewtopic.php?f=4&t=85055" onclick="window.open(this.href);return false;

I'll watch your thread with interest to see how it goes!

(Also thought I'd mention - we were camped next to you at Druridge Bay - did you get home with that clacking CV joint?)

I would agree Pete, I followed that thread at the time, it caused me to really check my engine over, which resulted in a new one. The mechanic changed it over to 95 and I'm yet to work out how to change it back. I'm getting a good 28mpg with 95, I would hope 30 with 98ron. The only thing that puts me off, is finding the right filling stations and not being forced to pay 10 - 15p more. On my UK roadtrip, I was shocked at how much difference there was and trying to find 98 all the time was a pain in the little villages we stopped at. We ended up paying service stations or taking big de tours.

Of course I remember Druidge Bay.... The dreaded CV Joint.

Well it was 8 hour, 4 truck recovery from Newcastle to Chester, to make it worse, my breakdown cover recorded this as 4 separate break downs and refused to cover me this year!

Your pics of the Northern Spain trip are brilliant, it really spares me on to my confidence to a level where I am happy to commit to a European trip with all the knoweldge I need to fault find and fix on my way.

I am almost sure that you are dealing with a faulty cold start valve.

Cheers

Jim

Ooo i like certainty... but would this not mean it suffered from the problem every time the engine was cold?

[silverbullet]

I think he's referring to the Idle control valve?

[bikermike87]

well... so far so good. Van is still running smooth as silk

Do you guys thinks I should leave it standing for a week to induce a fault, then rectify it?

Or continue to use it every other day and pretend it never happened?!

[PetenAli]

well... so far so good. Van is still running smooth as silk

Do you guys thinks I should leave it standing for a week to induce a fault, then rectify it?

Or continue to use it every other day and pretend it never happened?!

Personally I've picked up on a hint from, I think, Silverbullet on here which is that these vans benefit from being driven regularly so I'd use it as much as posiible. The best thing you can do for the engine is to make sure you change oil and filter regularly - a minimum of every six months if you don't do mega mileage. Have you checked the things that people above have suggested?

[bikermike87]

well... so far so good. Van is still running smooth as silk

Do you guys thinks I should leave it standing for a week to induce a fault, then rectify it?

Or continue to use it every other day and pretend it never happened?!

Personally I've picked up on a hint from, I think, Silverbullet on here which is that these vans benefit from being driven regularly so I'd use it as much as posiible. The best thing you can do for the engine is to make sure you change oil and filter regularly - a minimum of every six months if you don't do mega mileage. Have you checked the things that people above have suggested?

Thanks Pete, it does get used regulary and I keep it serviced regulary, it's the one things I can do and I actually enjoy it

Not had chance to work on it yet, last weekend was a right off, moving home and my van is still full.

But should I induce the fault by not driving it this week, that way I can work on it whilst it's broke. Rather than hoping that the changes worked, if that makes sense?