new distributor cap = juddery van

[marandali]

After a weekend camping in the rain our van wouldn’t start. A kind fellow camper who happened to be a mechanic said moisture might have got inside the distributor cap – so we took it off, wiped it dry and the van started. This guy also said that we need to get a new distributor cap as ours was pretty worn out.... So I went to my local GSF and bought a new distributor cap, rotor arm, leads and spark plugs. (thought I’d replace the lot in one go)

My first problem is the new leads won’t push on to the new spark plugs – I’ve pushed them really hard and they still won’t go on! Am I doing something wrong? Has anyone had this before?? (I’ve left the old leads on for now)

And secondly, I’ve fitted the new distributor cap, rotor arm and spark plugs, and now our van runs very juddery and it’s a lot slower too! Again does anyone know why this might be?

Our van is a 1.9 petrol automatic, 1988.
Please bare with me – this is probably the most mechanical job I’ve done on our van!

Cheers in advance,
Mark

[Aidan]

Ok so what did GSF sell you ?
What are the spark plugs, ie brand and numbers eg D7CCW, what brand are the leads, the cap and the rotor.
The advice is to only use bosch or beru parts all others are prone to being poor quality and causing issues.
New parts may not always be perfect so try swapping back to the old stuff one part at a time and see if that cures it.
If you haven't moved the disi and disturbed the timing then this is likely to be due to poor parts or wrong specced parts

when buying anything from gsf always ask for "best quality" as they may offer two or more brands of the same part and quality matters to our ignition system in particular, ok it may cost a bit more but repeated replacement of poor quality parts costs more in the medium/long term

[Ian Hulley]

My first problem is the new leads won’t push on to the new spark plugs – I’ve pushed them really hard and they still won’t go on! Am I doing something wrong? Has anyone had this before?? (I’ve left the old leads on for now)

You've left the suppressor caps on the plugs ... the new leads are for ones without the caps.

Ian.

[marandali]

This is what GSF sold me (I wasn’t offered any options… cheap or expensive):
Distributor Cap says Beru Germany VK 355cv on it.
The spark plugs are Bosch.
And the leads that I haven’t actually managed to fit yet say ErstKlassig on the box.

Does this all sound right to you?
Like you say I guess the next step is for me to put the old stuff back on and see what part seems to be causing the problems.

Ian:
Sorry if this is stating the obvious for you. But how do I take the suppressor caps off the spark plugs? Is it straight forward?

Cheers all

[Aidan]

they unscrew with a good fitting pair of pliers or mole grips

apart from the leads thats all good but what number is on the plugs ?

[marandali]

would you recommend I don't use the erstklassig leads then?

I'll have a look what number the spark plugs are when I get home tonight.

cheers

[Ian Hulley]

would you recommend I don't use the erstklassig leads then?

I'll have a look what number the spark plugs are when I get home tonight.

cheers

The leads will fit fine once the suppression caps are removed. DO NOT take the plugs out then do it (if you drop one in the hole you're in the brown stuff). Fit the leads one by one DO NOT take them all off then get them mixed up.

Buy a Haynes manual.

Ian.

[Aidan]

I'd check the resistance of the leads before fitting them, if they are in spec and a balanced set then use them, but as per SimonTMT's post below, new leads found to be out of spec and out of balance were part of the problem on his customers van and I remember Project Caravelle ended up selling his van cos of running issues and taking a massive loss only for new owner to change to a good set of used beru leads and hey presto all was fine, because the leads were new they weren't suspected, but new doesn't always mean they are ok

rotor resistance between centre and tip 1k ohm +/- 400 ohm

note rev limit rotor arms can also cause issues (intermitent esp.) and as long as you have ears that work and keep the sub at acceptable level you won't over rev it cos you will hear it scream well before you reach 5000 rpm.

ignition lead coil to cap 2k ohm +/- 800 ohm
ignition lead cap to plug 6k ohm +/- 1400 ohm

I had a set of leads from a certain supplier a few years ago that were between 5 and 12K ohm, van ran poorly and then blew up the hall sender, fitted a brand new dissy and it still ran rough; checked the leads and found the imbalance and replaced them with old ones that were all within 500ohm of each other and lo all was good again and no problems since.

[gti mad man]

wow wiki this

[Simon Baxter]

ErstKlassig is one of GSF's own brand of cheap imported Chinese toss.
Thing is with HT leads...
They are designed to be a set resistance, it reduces interfearance and prolongs the spark, giving a more thorough burn.
Now, there are generally 2 types of lead, copper core - no resistance and silicone - the longer they are the more they resist.
So, with HT leads it is preferable to have them all the same resistance, so the plugs are getting an equal voltage.
The copper ones are best as they have little resistance, but at the end they have a resisted cap, so they stay the same resistance through the length of the lead tip to tail.
Silicone leads however give unequal spark plug voltage as if one lead is longer than the rest then it has a bigger resistance, too big a resistance is bad.
The resistor at the end of a decent set of leads is usually 1K Ohms.

With the T3 WBX there are 2 types of lead - early and late.
early have the old scholl DIN fitting, the big old one like you used to have in the olden days, the better ones on the later vans have the ratchet on ends, or pin type if you prefer, or some manufacturers call them "saw tooth fittings"

Early cap is VK106 from Beru, sadly `Beru don't make a lead set to go with this type of fitting, only universal leads, in silicone and unequal length, not the best but works okay.
Late cap is VK355, this has the pin fitting, couple these to ZEF520 for a factory syle copper lead with a 1K ohm resistor at the end, this type needs the screw cap removing from the spark plugs.
I'm still chasing a relaible source of early leads of decent quality, but not found owt yet, Beru did make ZEF432 aned is listed to fit the T3 WBX but at some point the spec has changed and made the longest leads far too short, which is a real shame.

[marandali]

The spark plugs that I got from GSF are: SPARKPLUG-BOSCH WR7DC+
Are these good ones?

Aidan you mentioned something about 'rev limit rotor arms' causing issues... does this affect me as our van is automatic?

From everyone's feedback it sounds like I might be best off taking the Erstklassig leads back to GSF and not using them at all.

But with regards to putting the old stuff back in and seeing what is causing the issue... we may have a big problem! We keep our van on a mates drive and that's where I left the old dissy cap, arm & spark plugs... and it appears they have been safely put away in the bin! I'm going over there tonight to have a dig through the rubbish - fingers crossed the rubbish hasn't been collected yet this week!!!

[davidvincent]

The rev limiter rotor arm is a lot bigger than the standard and looks similar to this



The standard ones look more like this



I recommend always keep your old parts, especially the ignition parts which fail more regularly than others. I carry a spares box in my van nowadays

Also worth checking....... if you have vacuum hoses running round the engine/airfilter/dizzy (like this http://media.photobucket.com/image/vacu ... -Engin.jpg" onclick="window.open(this.href);return false;) then make sure you haven't accidentally knocked one off whilst changing plugs etc, that can make things run a bit lumpy too.

Dave

[marandali]

Found the problem, after wiggling and fiddling for a bit last night!

Even through all the leads were pushed on the spark plugs correctly, one of the leads had a bad connection - it was loose where the cable goes into the end bit that fits onto the plug (underneath the rubbery bit).

Running like a dream again now