E30 Zone

Would any one recommend a good specialist or someone who really know's e30s that can sort me car out ?

I've followed all the advice on here, spent months and hundreds of ££ and I'm no further on.

Basically when cold starting it idles poor, misfires and hunts. It also idles high at 800rpm. After a couple of mins it all settles down and idles fine.

It's using a bit of coolant from the bottle also and the exhaust has a fair bit of white steam when cold.

When driving it's also odd. If you approach a round-about and it's in gear as you slow down, if you are a little late getting it into neutral, and the revs drop to about 600, then dip the clutch (no throttle) and the revs shoot up to 1800rpm before dropping down to 800.


I can't work it out, I think I've tried everything.

I'm at the point now where I don't care how much it costs, I want it sorted.

I know it sounds like a vacuum leak but it's practically a new engine and I've checked and measured vacuum so many times.

Anyone know a M30 guru or good BM specialist where a proper time served engineer who could help me out for £££

I don't want to take it down the local garage where they have loads of polish 16 year olds doing the work and charge £40 an hour. I'd rather pay £60+ an hour to someone who figure it out and sort it !!

I had a similar problem on the cab Jim, and it turned out to be the AFM.
Changed it for a known good one, and it was fine after that.

thanks mate, I have tried that, well I have 2 good ones and it both does exactly the same. Both worked ok in the donor car. Might get another to rule that out if I can find one.

Were the AFM clean inside?

yer, they were fine mate.

Anyone know someone/ a garage who could have a look at this for me

Hants/Surrey/Sussex area

What ecu you running Jim?

The normal M30 ECU, ends in 179 iirc. I've tried 3 ECUs and they are all the same

I'm convinced one of the sensors is giving an incorrect signal to the ECU causing this. The problem is, i have changed them all and it makes no difference

I know it seems a bit of a long shot but i am going to change the cylinder head, inlet manifold, TB, hoses, ICV and TPS now, basically replace the whole top end of the engine.

Did the later M30 engines have an o2 sensor?

Also, I remember reading a thread once where the OP as similar issues, his inlet manifold gasket was duff and letting air in.

Your issue certainly sounds like an airleak Jim.

what injectors in this one?

standard M30 mate with injector tune re-furb

Flash it up on Wed - see what you think

Here is a description of what I can see !!

Cold Start up (CSU) = Fires into life, idles at 800, no white smoke/steam from the exhaust ”“ all clear

CSU + 2 mins (so the temp needle has just moved away from the stop) = Loads of white smoke/steam, hunting idle, misfire and won’t hold a steady revs at 1500, keeps hunting and misfiring.

CSU + 5 mins = idle now stabilised 800rpm and no misfiring but still lots of white smoke/steam ”“ temperature approaching the first line on the dial, about 10 o’clock position

CSU + 10 mins = idle steady at 800rpm and no misfiring ”“ engine now up to temperature (just below 12 o’clock) and no white smoke/steam.

Other things I have noticed.

I’m only getting an average of 20mpg

When forcing the engine idle below 800 by slowing down in gear, say to 600rpm, if I then dip the clutch with no gas, it shoots up to almost 2000rpm and then drops down

Dissconnecting the ICV has no impact to the idle speed.

The throttle stop is fully wound in and the throttle is checked closed at idle.

When I’m driving it feels like an old car with a manual choke which is fully out ”“ it kinda drives it’s self.

Things I have done:

Replaced the following with new OEM parts:

Dizzy + rotor
TPS
Blue temp sensor
Vacuum hoses and the blank on the bottom of the inlet manifold
Inlet manifold gaskets
Sump gasket
Oil dipstick tube seal

Replaced the following with known good parts ”“ all these had no difference

ECU (tried 2 others)
Crank sensor (tied 2 others)
HT leads
AFM
ICV
Alternator
Coil
Changed DME relay

Checked compression at 195 every cylinder

New cylinder head gasket

Head reconditioned

Crank vibration damper toothed wheel is clean and CPS gap set to 1mm (maybe a bit less)
Injectors have been ”ainjector tune”a cleaned

There is a small oil leak from the back of the cylinder head blanking plate

There is a small exhaust leak when cold from the manifold log gasket

The car drives very well when warm, pulls strong through the whole rev range

No obvious wiring defects but I did have to splice in a C101 plug as the loom (manual loom) had an x25 plug on originally

The engine is fitted with a Shrick cam, 0.5mm skimmed head and BBTB (I’ve tried a normal TB with no improvement) and e28 535 flywheel.

There is no O2 sensor on the exhaust.

The engine has 2 mega large and well connected earth straps. The battery is well earthed also.

I havn’t checked the resistance of the blue temp sensor at the ECU pins yet but will do asap

The car is also loosing coolant from the tank at the rate of about 1 cam drop (about 100ml) every 200 miles.

The temperature stays very stable and only reaches the 12 o’clock when stuck in traffic but is quickly checked back by the mega kenlow fan.

I’m now at a loss on what to do next.

I have a spare cylinder head and most of the inlet system so might try fitting that next.

Does anyone have a spare manual M30 loom i could try to see if i have cocked up the x25 splice ?

I had the exact same problem with my old m30'd e30.

It turned out i didn't bleed the coolant through properly after I replaced the radiatior

really, wow, that's interesting

how can that effect the idle hunting and missfiring ?

thanks

jimbom30cab wrote:I havn’t checked the resistance of the blue temp sensor at the ECU pins yet but will do asap

This should have been the very first thing you did. You should also ensure that the TPS signal is getting to the ECU as well, as it's got to be one or the other of these things.

All in I'll, I'd sit down with a multimeter and confirm that the loom is properly done. This is a Motronic 1.3 system, right?

http://www.e30zone.net/e30zonewiki/inde ... tronic_1.3

Thanks mate, i will do that, i did just fit a brand new Blue temp and assumed it would be ok, it made no difference to the others though.

You know i strongly suspect the wiring is wrong so a new engine loom could be an easy fix.

I did measure the voltage accross the ICV pins 1 to 2 and 3 to 2 and it was very wrong on one side. The ECU is giving out the wrong signals i'm sure of it. I've tried 3 ECUs all know good ones so i'm convinced now the ECU is getting a duff input and like any computer, sh1t in = sh1t out.

Thanks

Your ICV sounds funky too, makes the revs rise when in motion?

Putting the clutch in and letting off the throttle makes the TPS send a signal to the ECU to change from running to idle map thus kicking in the ICV.

That transition between running to idle sounds like its off. Incorrect calibrated TPS or duff ICV?

I completely agree with you Chris, and I think the issue must be in the loom. The ICV is the one off my tech1 which I did 10,000 perfect miles in. The TPS is brand new OEM.

too late to think about this stuff now

cheers matey

Jim

You can use m20 ICV on m30 donks?

yer, it's the same part number mate.

Never knew that.! Time to get the multimeter out Jimbo and get diagnosing that loom.

ok mate, check your PMs

*facepalm*

When pumping brake pedal should the revs raise?

Right guys, I've got a potential solution lined up to sort this running issue out

It's a................

New engine



Good runner and I'm going to drop it in lock stock (soon as I can get a c101 plugged manual loom for it - it has an x25 plug)

Hope this does the job

Good luck champ!!

Thanks

Right well good old Rob on here fitted the new engine and it solved all the problems i had but......

It has low compression on all 6 cylinders - about 80psi every cylinder roughly the same

Now, the timing has not been changed, the engine went in lock stock complete

It did idle and run perfect when we put some oil down the bores to bump up the compression but after 5 or 10 mins running it just died and wouldn't start again.

Hot compression test was 80psi all cylinders

Also, when cranking the engine over on the starter, if you take off the oil filler cap, all the compressed air from the pistons comes out the filler cap, looks like an exhaust !!

There is a lot of oil in the intake system also

So 100% the rings are not sealing. The odd thing is, it was a perfect running engine in the donor car. So why is it not running now?

I've ordered some miricle oil to soak the rings in and hope they seal again, otherwise it's a new set of rings needed.

Diesel

Thanks, i bought some of this:

http://www.ebay.co.uk/itm/281225187082? ... 1497.l2649

jimbom30cab wrote:The odd thing is, it was a perfect running engine in the donor car. So why is it not running now?

I've ordered some miricle oil to soak the rings in and hope they seal again, otherwise it's a new set of rings needed.

did you see it running in the Donor car? the pulleys look to have a fair bit of rust on them in the pic... suggesting it's been sat outside for some time ?

the miracle oil will work just as well as the magic beans my mate got down the market at the weekend

e30topless wrote:

jimbom30cab wrote:The odd thing is, it was a perfect running engine in the donor car. So why is it not running now?

I've ordered some miricle oil to soak the rings in and hope they seal again, otherwise it's a new set of rings needed.

did you see it running in the Donor car? the pulleys look to have a fair bit of rust on them in the pic... suggesting it's been sat outside for some time ?

the miracle oil will work just as well as the magic beans my mate got down the market at the weekend

Mate ......no amount of miracle oil will cure a tired engine !! Am happy to take a look if you could leave it with me

Actually .....i read somewhere that that stuff is really good at rust removal !!

Thanks guys and Gus for the offer.

I have faith that the miracle oil will not only get her running like new again, but remove the rusty bits, polish the bodywork, rejuvinate the interior and give a big hike in BHP.

jimbom30cab wrote:Thanks, i bought some of this:

http://www.ebay.co.uk/itm/281225187082? ... 1497.l2649

Jesus Jim, I had you down as an intelligent chap

Looks like you've been sold a lump of scrap, there is no way that all 18 piston rings have stuck in a way to give the same compression on all cylinders