Starting an M30 that has not run in 6 years..

[Jos]

Guys, whats the best procedure for starting an engine that hasn't run in 6 years? Its an auto e23 735i.

I was thinking:

Change oil and filter
Change petrol
Clean plugs/dizzy
Loads of charged batterys

Crank with no accelerator to get oil circulated, then go for the gas and see if it will fire.

Should I put a flush kit in with the 1st oil change then change it again shortly after?

Would Easystart be a good idea, and can I just spray it into the air intake without fear of damaging/upsetting the AFM?

Ta in advance guys

[Geeman]

Can you crank it over by hand first to see if it's seized or not...

Take the coil off, so it won't start, then the oil will get round before firing it up...

Just a few suggestions...

[tbmw]

beat me to it geeman was just about to say the same thing
crank it with no spark first

[Paul325i]

I wouldn't use a flush kit, old engine like that you'd want to keep the carbon deposits in there.

I'd throw in some fresh oil and a new filter, turn it on the crank like geeman said as you can't rock it in gear.

[M3Compact]

Take the coil off, so it won't start, then the oil will get round before firing it up...

Take the plugs out to spin it over, no compression, faster spin, better oil circulation without firing up, also less battery drain.

[Karan]

#1 make sure its not seized really....

[Jhonno]

Take the coil off, so it won't start, then the oil will get round before firing it up...

Take the plugs out to spin it over, no compression, faster spin, better oil circulation without firing up, also less battery drain.

i go with this one..

[Toby_Unna]

you can stick a paperclip in the fuel pump relay contacts (pins 30 and 87) with the relay removed to circulate the fuel and build the pressure in the fuel rail to 3 bar.

not really essential but it might not want to start immediately and you don't want to run the starter for 20 secs unnecessarily while it builds up fuel pressure , the starter isn't much fun to change on that engine!!!

i also find those engines REALLY don't like the dizzy cap being damp even if just a bit of condensation (i assume yours is motronic, don't know much about e23s) so as you say make sure it's clean and dry...

good luck; cool car!

[glenn]

definatly crank it without the plugs for a while, give the oil pump a chance to pick up oil

[AndyG]

Toby's right. If it's a 3.5, it'll be motronic, and he's right about the dizzy, the cap and rotor arm are crucial to good running on these engines.
Plus if it doesn't run, check the sensors that plug into the bell housing, remove them (gently) clean the contact faces and replace them, and clean the electrical contacts thoroughly, if one of the sensors isn't sending the right info, the car will either not fire at all, just turn over, or will not rev over 1000rpm. The CSV also clogs up, so should be cleaned out, other than that I'd turn it over to get some oil moving, then have a go at firing it up.
There's also the dme relay that sits on the bulkhead (effectively in front of the driver?) and the pins do corode, so clean these up carefully. Lastly, check the ECU isn't soaking wet, it sits behind the speaker grille in the drivers footwell, if it is, dry it out, and reconnect.

[Toby_Unna]

ha ha i bet after all this it just purrs straight to life!

the e34 motor i put in my car last month had been sitting in the 535i breaker outside all through winter and for ages before that, i was expecting a nightmare to make it run with all the re-wiring into the e30 etc but it just came straight to life first turn of the key.

had new plugs and dizzy though, that helps a lot!

[john325tewerin]

Before turning the engine, take plugs out and spray some WD40 type penetrating oil around the bore and leave over night - this should help free up any rings that may have started to sieze and reduce the chance of damage to the bores.
And you may as well clean up the plugs while you've got'em out.

[andyp]

Before turning the engine, take plugs out and spray some WD40 type penetrating oil around the bore and leave over night - this should help free up any rings that may have started to sieze and reduce the chance of damage to the bores.
And you may as well clean up the plugs while you've got'em out.

took these words out of my mouth

[Jos]

Lol, I hope so Toby, that would be great!

Pretty sure it hasn't seized, its Motronic 1 based and the ECU is dry as is the fusebox, haven't checked the dizzy yet although it is a fairly new cap (6 years)

Following advice from my father (marine diesel engineer and a handy bloke to know:)) I have decided on:

Remove plugs, put little drop of oil down the holes, turn crank with socket a few times to get some oil round the liners and top of the cylinders.

Drain fueltank using bung, put 5l of new stuff in, disconnect the fuel hose going to the injectors, crank the engine a couple of times on the starter, this will blow the excess oil out and also pump the crappy fuel out of the pipes. Reconnect fuel line, put pulgs back in, cross fingers and hope she fires. If it don't I will check through the list of stuff u guys suggest.

Ta very much, will keep you posted.

[Jos]

Before turning the engine, take plugs out and spray some WD40 type penetrating oil around the bore and leave over night - this should help free up any rings that may have started to sieze and reduce the chance of damage to the bores.
And you may as well clean up the plugs while you've got'em out.

took these words out of my mouth

Lol, mine too, had a reply ready to go from 5 hours ago, forgot to press Submit ...

At least we all thinking along the same lines... great minds and all that BS..

[Jos]

Ok, so I got to have a look at the engine today, fuel pump relay wasn't working so we papercliped it, fuel pump running ok and loads of petrol out the injector rail.

Sprayed WD40 in the plug holes, left for a couple of hours and then cranked it, she turns over lovely...however....

I can't get a spark from the coil, tried a different coil, same result. There is 12V or so at the coil, so its getting power ok, but there is nothing out the other side, dizzy and rotor are brandnew and totally clean.

I tried just touching the HT lead off the block and didn't get a spark at that point either..

Any ideas guys?

[AndyG]

you may have a sensor down. There are two situated on the top rail behind the inlet manifolding/AFM etc. They sit on a metal bracket, ensure the connections are clean, and if possible, remove each sensor face and clean properly and the replace (one at a time in order not to confuse the ECU), one of these if down prevents the car from starting, the other will not let it rev!
How about your leads? May be a knackered lead from the coil to the cap?

Try this site http://home.bellsouth.net/p/s/community ... 160912&ck= although aimed at the 6 it's a good reference for these types of problems.

[Jos]

Thanks for the pointers, I had another go at it this morning, but still no joy, I couldn't really get at the sensors to clean them, so we decided just to pull the engine and worry about getting it running on a frame. At least then everything is accessible, I am a little worried about the ECU, there is no 12V on the coil side of the fuel pump relay at any point during ignition or start, fuse is ok, didn't check wiring going back to the ECU though.

If the ECU is dead, I will probably go for a standalone, any recommendations?

[A1BMW325iSport]

wiring from ignition switch is faulty, its not throwing 12v to the fuel pump relay when cranking.

[Jos]

Ta for that, I will give it another go when its out on a frame, too much taken off it now to try again in-situ.