Mi16 (2.0L) Odd Ignition/ht Problem - 2 Cyls Sparking Only

[welshpug 1,657]

poor quality mouldings, overtightened screws, warped base plate, fitted pointing the wrong way possibly.

[petert 586]

Or a crack. The spark has to be going somewhere, if it's leaving the coil. Have you had a look at night with the lights off?

[S@m 156]

Is the centre pin in the cap still moving freely against its spring?

 

 

I've had mi's running fine with gaping holes in the dizzy cap (a screw came out of the rotor arm), but as soon as that spring in the centre loses it's tension then i've had all kinds of misfiring issues.

 

Maybe i got lucky with the hole being in just to right place but that's my experience.

[DrSarty 90 1 Cars]

I remain completely confuzzled. I'll go beyond that and say I'm stumped!

 

After £75 worth of new Valeo rotor arm, dizzy baseplate, dizzy cap and HT leads (x5) there's no difference.

 

I'm sorry to say this is what I expected, as the original items were all new anyway; I was just hoping it may have been a dodgy cap.

 

In doing the above, I also removed and replaced the rotor arm base/foot attached to the cam shaft, and fitted everything (again as before) super carefully to ensure I hadn't somehow assembled things incorrectly.

 

From previous tests it appears clear that the spark from the coil to the dizzy cap is strong and regular; it only seems to go wrong - on cyls 2 & 3 only - from dizzy cap to spark plugs. What on earth is going on?

 

If the rotor arm was on the p1ss, or the foot it sits on, or dare I say it the camshaft (?), I'd understand that the rotor arm wasn't spinning evenly near each contact in the cap. This may be proven by the fact that it's cyls 2 & 3 that don't seem to fire properly, which aren't similar contacts in the dizzy cap, i.e. they are one of one type and one of the other (you'll understand if you see inside the cap).

 

I'm going to use the spark tester again, as before, but with the new components; I bet the results are the same.

 

There simply has to be a simple explanation but I'm buggered if I know what it is.

 

I'd be really interested to hear and see how a properly working coil to dizzy Mi HT connection works. If anyone could video a spark tester sited between the coil and dizzy cap (on the 'king lead') so I could see how often the sparks appear and how strongly I'd have something to compare it against.

 

To assist, I'll video and post my results so you can see what I see, but I'd really appreciate more assistance please ASAP.

[DrSarty 90 1 Cars]

Video to follow this weekend, but anyone got any ideas?

 

How can the spark seem ok TO the dizzy cap, but be odd coming out FROM the dizzy cap to cyls 2 & 3 (whilst being fine on 1 & 4)?

[Anthony 1,003]

Logically it has to be related to either the dizzy cap or the alignment of the cap and arm.

 

Out of interest, do you have an 8v dizzy adapter that you use to run an Mi16 on carbs hanging around in your parts stash? If so, fit that so that you're using the 8v cap and arm for spark distribution (but still Mi16 management) and see if the problem disappears, as that will solve any alignment issue.

 

I did that a good few years ago to try and identify an issue that was causing the dizzy caps to fail within a few miles on my Mi16.

[Hilgie 16 2 Cars]

This topic is over a year old, but I did not see any solution.

 

It could be that the ECU used is from a 2.0Mi16 (which has wasted spark ignition, so 2 ignition amp drivers) and you have converted the engine to dizzy and coil from a 1.9Mi16 (which has 1 ign amp only).

 

In other words, they ECU drives the ignition amp only half the time (the other half is going to the second ign amp, which is clearly missing in your case).

[jackherer 543]

Haha yes that could well be the issue! Or at least something to that effect, it seems obvious now you have suggested it. I just re-read the first page and Rich even says this:

 

 

> 3-row Mi16 ECU used based on recommendation from PeterT, who is well trusted on here
> the ECU also has a PeterT chip which I believe is designed for the 2.0Mi (it has a 2.0Mi16 label on it)

 

Would a 2.0 chip run at all in a 1.9 ECU? If it did it would presumably only trigger the single coil wire half the time which would result in the symptoms RIch had.

 

Has anyone heard from Rich lately? It looks like he hasn't been on here for a year.

[welshpug 1,657]

DERP!

[petert 586]

You definitely can't swap chips between 1.9 and 2.0, even though they physically look the same.

[DrSarty 90 1 Cars]

I'm still here. Not been on the forum for a while, but these recent responses are a revelation. Looks like it's as simple as that.

 

I'm not going to bother pursuing it though with this solution (explained below), although I am intrigued by the ECU seemingly only having 1 coil trigger, as perhaps I'd now expect it to have two. Just a query and happy to hear what's said.

 

Reason I'm not pursuing is:

• My white 205 with the GTI6 engine, after several years of fun just experienced a shattered exhaust cam pulley (?!)
• My Miami (with the topic engine in), is going to donate its engine to the white car, along with some new ITBs, the 4-2-1 exhaust from the Miami and get a remap at Emerald
• The Miami shell can then be sold to make space. All it needs is some TLC and an engine. (Look out for 'For Sale' ad - it used to be Goliath's V6)

I'll never know therefore what this OE upgrade engine would've been like.

 

So I'm around, skulking about, and even awaiting some DFZ (IIRC) pistons and stage 1 cam from PeterT to arrive in the post to make a Mi16 turbo out of one of the 5 Mi16 (plus one GTI6) lump I have laying around.

 

WTF does "DERP" mean?

 

P.S. Do Colin and Sandy still do their ITBs (ready for staged injectors), or would I be right in saying Pug1Off do a similar set? I am hoping with this fresh 11:1 engine, its fast road cam and new bodies, it should be a 200bhp motor.

Edited May 24, 2016 by DrSarty

[welshpug 1,657]

its a variation on DOH!

 

Unfortunately the cracking of the early 3 bolt pulleys are getting more common, it was the reason for the later single bolt adjustable pulley.

 

satchell still do their dcoe inlets using a standard xu inlet as a base, so doible injector setups are easy and not much more expensive.

[DrSarty 90 1 Cars]

I've got the joys of this venture this weekend. Can't say I'm looking forward to it, so any other recommendations appreciated.

 

ALSO: What servo replacement options are there please? My parts supplier said "it's a minefield of options" and that they'd appreciate me supplying the brand and part number of the servo I'm removing. Can anyone help with that info OR can I use one from say a 406? I'm already using a 406 (23mm) M/C.

[welshpug 1,657]

ecu will have two coil triggers but in a 1.9 loom the wire wont be there.

[welshpug 1,657]

servo?

 

only one option iirc for a rhd gti, 200mm bendix/dba.

406 servo is MASSIVE.

 

205 servo will cross reference to many others like zx 306 xsara

[Miles 331 1 Cars]

you can get a 306 servo in but the scuttle panel where the wipers are needs a slight tweek, The listed ones on ECP etc are for LHD car's

Edited July 7, 2016 by Miles