Eddie's E21 316

[Jeroen]

Pipe no 8 on below diagram. But get a used one, they've become bloody expensive through BMW

[Eddie.]

That drawing is for a FL cooling system and engine though? I have a PFL engine and subsequently, a PFL rad and cooling system.

[e21-Mark]

Aren't the thermo switches put at the bottom for a reason though? Aren't you measuring the temperature of the cooled coolant at the top? (I may be wrong, but am sure I've read something like that?) I replaced the OE type thermo switch with a tropical version and it was fine. There's not much that can go wrong with them, once you fit one less than 30 years of age.

[Jeroen]

Imo it doesn't really matter where the switches are placed, as long as you adjust the spec to the location, that's what BMW did as well. At the bottom of the rad it needs to switch on at a lower temp of course.

[Duracel79]

That drawing is for a FL cooling system and engine though? I have a PFL engine and subsequently, a PFL rad and cooling system.

The rad you have looks to me like a 4 cylinder radiator to the inlet/outlet ports are in different positions to the M20. Also has a radiator cap, so with the expansion bottle you now have two caps, not sure how that will work.

On both E21 pre-facelift and post-facelift M20 radiators the hot inlet port is ~2/3rds along the top of the rad on the drivers side (RHD). And the cooler return is at the bottom corner on the engine inlet side.

Pre:



Post:



E30 Pre and Post facelift are different to this:

E30 Pre-Facelift - has the hot inlet in the top corner of the rad on the engine inlet side and the cooler outlet on the same side of the rad at the bottom (engine inlet side)



E30 Post-facelift - has the hot inlet in the top corner of the rad on the engine inlet side and the cooler outlet on the opposite side of the rad at the bottom (exhaust side)



Hope this helps

Ben

[Eddie.]

Sigh, it would seem things go from bad to worse then.

I sorted the pipes out last night too (or thought I did) but I suppose it won't work with the setup I have?

I can start the engine still, as long as there is a circulation of coolant I'll be fine, I'll just have to make sure that I don't allow any heat to build up!

I should only blame myself I guess, but the seller on eBay did list the radiator as a PFL E30 6cyl unit.

[Eddie.]

can you use a FL rad on a PFL?

[mr edd]

eddie ...is your rad off a e30 pre facelift 4 cylinder as i imagine a 6 cylinder rad wuold not have a rad cap on the rad as the rad is filled from the header tank?...a facelift e21 6 cylinder rad and hoses might be the best fit.(it would fit in the cutout in the front panel)....i imagine a e30 facelft rad would not fit the same but if wanted to try one i have one spare..edd p.s Any luck with the metal cut out from the front panel.....

[Eddie.]

eddie ...is your rad off a e30 pre facelift 4 cylinder as i imagine a 6 cylinder rad wuold not have a rad cap on the rad as the rad is filled from the header tank?...a facelift e21 6 cylinder rad and hoses might be the best fit.(it would fit in the cutout in the front panel)....i imagine a e30 facelft rad would not fit the same but if wanted to try one i have one spare..edd p.s Any luck with the metal cut out from the front panel.....

I'll have a search for some rads, see what I can find.

With regards to the front end metal, this is what I have:



All yours mate, I can probably drop it off one night after college if you're about? Or you're more than welcome to come and get it one evening.

[mr edd]

Pm sent.

[Eddie.]

So today was the first attempted start of the M20. Key word being "attempted".

First off, there was no starter motor, turned out I'd missed a ground strap, and the switched live on the SM had come undone, so that was fixed, but the SM tried to crank as soon as I connected the battery, that was because the switched live and permanent live (from the battery) were too close, and were arcing across. Some insulation tape and relocation of the wires sorted that.

With the engine now cranking, it was time to check the fuel pump, which seemed to be okay (apart from me forgetting to fit the fuse that I had wired in!).

So the engine was getting fuel and crank, but at this point we identified that there was no spark. The coil was getting the required 12v, and the resistance between post 1 (-) and 15 (+) was the correct 0.5 OHMs, the king post was the correct 5000 OHMs, and the coil to dizzy lead was the correct 2000 OHMs, so all seemed fine there.

Anyway, I started looking at sensors and the possibility of the ECU not providing spark. CPS at the front of the engine was fine, but I noticed that the gearbox that came with the engine had two sensors in the bell housing. One is a speed sensor (irrelevant to me) and the other is a CPS reference sensor (or so I believe) The gearbox that is on my engine is an E21 gearbox and is required as it has the necessary provision for the mechanical speedo drive. That E21 gearbox does not have a provision for the CPS reference sensor, which means the ECU isn't getting a signal that it thinks it should be, and thus is not providing me with a spark.

So my options are:

- Run the E30 gearbox and use a GPS speedo drive + other mods.
- Keep the E21 gearbox and upgrade my Motronic 1.0 to a Motronic 1.3.

I'll probably be doing the latter because the gearbox swap requires the engine to come back out, and also means bodging the speedo. The Motronic 1.3 swap would be better because the M1.3 doesn't require the CPS reference signal, it uses a single sensor on the crank at the front of the engine. There is a cost issue with the swap though, as I'd need a fair few bits, but it's still probably the best option for me.

I also noticed that my ICV seemed to be on permanently, suggesting it was somehow on a permanent live. I'll see if that is still the case when I swap over to M1.3 and if so, address it then.

So in all, it seems my work/mods are fine, and the car would have started today had I known about the CPS ref sensor, but these things happen I guess.

Off to eBay I go to cost it up...

Also, a big thanks to Nas, who spent a fair bit of time on the phone to me today, thanks very much mate.

[e21-Mark]

Stick at it. It'll be worth all the effort.

[drjim]

I have a spare 1.3 ecu in the garage.

[Eddie.]

Oh really? Something you'd want to sell?

[nas80]

Hey no worries Eddie. Tbh I'm glad I helped in some way. At least you have a direaction