1.8 16v KR On Carbs Conversion, Wiring Help Needed ECU/TCI

Car was 1.6 carb, now has 1.8 KR on dhla 40's, here is the patient at the moment:



now have 205 dizzy cap so no fouling.

We have a few gremlins with it, just a few quick questions please.

When using the KR engine on Carbs, is it reccomended that we use both the TCI AND the ECU, or can we just get away with using the TCI? What does the ECU do exactly? Is it required for advancing timing?

Currently the car has the TCI fitted to stock KR dizzy and it seems to be over advancing the timing on startup, basically feels like it's kicking backwards on the starter.

Has someone got the wiring diagram, and I don't mean this thing:



or this one:



It's getting to be a bit of a joke now, want to eliminate if the hard starting problem is due to the lack of ECU or not, my mechanic is certain it does not need an ECU but I have other thoughts. Help please, urgently!

Car is in northampton so if anyone is a big expert and wants to come have a look and offer advice that would be great, few beers in it for you! Or cold hard CASH if you solve it. lol

Literally going mad now, car's had new battery, starter but its still kicking over super slow, it starts on a tow start but won't idle, drives sort of OK though providing carbs havent been tuned yet.

Going to go cry now, send help

Ry

Without the ECU you'll get no speed or load related advance. So it will be too advanced at starting and idle, and too retarded under full load or at higher engine speeds.

So, you need the ECU to get any sense of normal driving and performance, but in theory you don't need the ECU to do a basic check and start/run the car (tho its performance will be lower than it should).

So the ECU links in with the TCI? As my mechanic seems tho think that the TCI is a stand alone unit and doesn't connect up to the ECU at all, and that the ECU is not needed to advance the timing.

It's very frustrating. Thanks for input Paul

Has anyone got any pictures of how the wiring should all go together, and I mean individual wires joined up, not hidden by a big black sticky insulation tape terror. lol!


 :dontknow:

Change your mechanic

Bring up mine I'll sort it

paul_c said

Change your mechanic

thanks… :roll:

Pm sent Keets

UnmuffledRyan said

 When using the KR engine on Carbs, is it reccomended that we use both the TCI AND the ECU, or can we just get away with using the TCI? What does the ECU do exactly? Is it required for advancing timing?. . . seems to be over advancing the timing on startup . . .  my mechanic is certain it does not need an ECU

It?s not recommended, it is required! (with exceptions). There are four ways I know to run the 16v on carbs, ignition that is, two I have experience with and two I have just heard and did some research on. One is buying products from a company called MSD, a programmable ignition timing box and a CD ignition box like the MSD-6A. This is an expensive deal but works very well and can be swapped to other engines in many cases. Then there is using  the factory ignition control boxes and ignition module. This works well, is cheaper and you can even run a knock sensor if you install some micro-switches. Another is using a Saab ignition distributor, don?t remember which engine it comes from and the last is to use a VW small block ignition distributor (often referred to as a Polo distributor in forums). Both of these last two use mechanical/vacuum advance and require playing around with the timing curve to get it right.

The ignition is not over advancing the timing, the timing is set statically over advanced. Without the ECU in the system and using the factory KR ignition distributor you have fixed timing, no advance and no retard. So to have the engine run at least a little after you get it started the distributor has to be turned to advance the timing, but then it is too far advanced for starting, hence the kickback. And when you do get it running it will not run or idle good as the timing is set for only one narrow RPM range and zero load. The engine needs the ignition timing to be able to advance and/or retard to run right throughout the entire RPM/load ranges. By the way your mechanic is both right and wrong about the TCI being stand alone, but it can only be used alone on mechanical/vacuum advance distributors with Hall senders in them.

Unless you plan to build your own harness, the first diagram shown is fine. I didn?t look close enough to see if all the wires were present or labeled right, but the basic layout is correct. Now if you think an exact drawn up diagram or factory flow diagram would help more I can send you either.

Righto, its battle of the wills at the moment, I think me and the mechanic are warming up for a wrestling match later over this, he was right that the TCI isn't linked, but then ECU is needed so its 1-1. lol

What you are saying makes perfect sense, when we did get it running (turning the dizzy til it started) had to keep the revs up, then when I turned it one way the RPM went up and it started running better, I've set timing on other cars and I'd normally consider this the sweet spot, then cut the car, tried starting again and it wouldn't (kicking back against the starter again).

One thing that confuses me is the car is driveable and said to pull really well. eurgh…

I found this diagram:



If you could send what you have that would be great. The one above shows the ECU connected to the hall sender on dizzy, yet somehow my guy has whacked the TCI onto the hall sender? MASSIVE confusion! To be fair he just had a stripped engine to start with and no loom / ecu etc.. at all so it's a bit of a jigsaw puzzle.

Send any diagrams to:

ryanandmorgan@hotmail.com


Cheers

Ry

Not at a location that allows me to view any pictures (blocked) and will also have to wait until I get home to send any material. Would email be best? I might have to get the stuff scanned first as I'm not sure I have much of anything on the computer. So it could take a day, but as for the rest of what you just posted:

In this case you are correct in that the TCI is "linked" to the ECU. There are systems that do not have an ECU of anykind and use only the vacuum and weights inside the distributor to adjust the timing advance. Think of the TCI as an electrical set of breaker points (it is really just a switch). On a points distributor the breaker points open and close via cam lobes on the distributor shaft and the spark advance happens due to mechanical/vacuum rotation of the plate the points are attached to. On electronic ignition distributors the space in the trigger wheel allows the Hall sender to make a small power spike and that is used by the TCI to collapse the ignition coil. Some electronic ignitions also use mechanical/vacuum advance distributors that work like the points versions, they just use a Hall sender in place of points. The benefit is more precise timing and no wear for longer life.

Where the ECU comes into play is with fixed distributors. As there are no plates to rotate or springs/weights or vacuum canisters to do the moving, it is all done electronically. The ECU recieves the engine speed (RPM) via the ignition coil and the load placed on the engine via the vacuum hose and does the computation in mili-seconds to adjust the spark. The wires run from the ECU to the distributor (Hall) because it is in charge of when the spark fires and when based on it's ignition map stored inside.

The engine might run some-what OK once started because timing is not all that important in the engine operation as some might think. In most cases there is only about a 2500RPM engine range where ignition timing varies much. Idle, lets say 1000RPM is where the static timing is set, again say 10 degrees (nobody uses that 6 degree setting). Then there is the maximum advance that the timing will go, lets say 36 degrees (about right for many engines). Maximum timing, "total advance", is completely in on most engines at around 3500RPM (some closer to 4000 but not too many). That leaves about 2500RPM where the timing advances between 10 degrees and 36 degrees (26 degrees in all). Then there is high engine speeds which require a lower timing of say 4 degrees to run good. So if say the ignition timing were set at 24 degrees it would run fairly well from 2000RPM to redline, better in the middle range, but would be very hard to crank and start with that much initial timing. Clear it up any? Need anything made more clear or detailed?

Spot on grimy fingers, I think as stated before the lack of ECU is causing the hard (impossible) starting as it is over advanced, but then it runs well when moving. Dropping down to idle it has too much advance and dies out.

I have got my head around it, just got to find an ECU and loom to fit (and convince the spanner spinner that it is the problem) :wink:  :wink:

No rush on the wiring diagrams but it would be nice to have them as a matter of course to use when wiring in the ECU to the existing TCI / Hall sender loom.

Thanks again grimy fingers, good explanation, and not rude like some people…

Ryan

get the complete 16v ignition controller loom and you're laughing,. no wire splicing is required. rip out everything between the tci, dizzy & coil and replace it with the 16v stuff.  If you look at the coil you have 2 black wires, and 2 red/black wires (one of the red/black wires may be green insteds tho)

you keep the red/black and black wires from the original loom to the fusebox, black is the ignition live feed to power the coil and the red/black is your rev counter wire.  The 16v loom plugs onto the other terminals onto the coil, you'll note the 16v loom may have a double plug with a red/black and a green wire, what you do is pop your red/black wire from the fusebox into this plug and pop it onto your coil, job done.
There is absolutly nothing running to the fusebox, its dead easy
(Well, there is the isv control unit wire, plus the fuel pump relay trigger, but you wont be needing either of those)

If you pm me your email addy I have a complete pre-90 MK2 16v wiring diagram, but tbh all you really need is this:



1 - Earth to battery -ve
2 - KR ign controller plug
3 - TCI-H plug
4 - Black - KR ign controller & TCI-H ign live - terminal 15 side of coil
5 - Green - Coil trigger - terminal 1 side of coil
\- red/black - spade is for the isv control unit, the main wire is the rev counter feed
6 - Brown - Earth to cylinder head
7 - Blue/white - Temp sensor feed (use one of the 3 on the side of the head)
8 - Dizzy plug
9 - red/yellow - Fuel pump relay earth trigger
\- black/yellow - idle switch feed (12v feed with throttle shut)

All of that apart from number 2 is present and plugged in (probably the most important part, lol), going to try sourcing an ECU and fresh uncut loom to put in.

Anyone got one kicking about that can be got super double quick time?!

send any bits of juicy info to:

ryanandmorgan@hotmail.com

Cheers

Jonny, absolutely 110% clear on what's needed, ECU and associated loom, clag on existing parts in the car and it should fire up trouble free.

Thanks all

Ry

yeah #2 is the most important bit, the kr loom will replace all of the existing gubbins

as long as you have a complete uncut ignition controller loom in good nick, thats everything. the ignition controller needs a vacuum input from one of the chunky brake servo hose nipples, and it also needs a temp sensor input. there should be 3 on the side of the head, if not your old MK1 dash temp sensor will work, or from another random vag car.  see em all over the place, 3 on a kr engine, the abf mk3 uses one for the dash, most mk1s and early mk2s have them, etc.

just needs to be one with a black collar. the white collar ones are for the MFA oil temp, and are a different rating.

temp sensor is on the motor, tci connected to the Hall sender, earth, coil wires done, just no ECU or connector, thanks for the wiring diagrams, just having a scan through them and redrawing it so I can use it as a quick reference. Wonder what happened to the ECU and plug then… Probably in a landfill covered in old sweetcorn with a seagull shitting on it.

GOLD mate, thanks for the help.

ECU and loom for 16v KR wanted! lol

Ry

Here is a page from the factory wiring book. Only the wire that runs to the throttle switch can not be seen completely as it runs to a second page. Your last drawing that you posted is exactly the same, only here you can note the factory wiring colors. The boxes should not be that hard to find, I know someone in the states who just purchased one from the UK shipped for $60.