URGENT HELP!!! Fitted head etc, now wont start!

[Dan320is]

I have put my 325i Touring back together after having to have the head off as 4 exhaust manifold studs broke off.

It has fuel at the rail
It has spark
It turns over

It turns over, after a few seconds it starts to run lazily, then just runs out of puff and dies.


Has anyone got any ideas??? I'm going absolutely crazy!!!!!

Ant, anyone?

[325sportcab]

Just a guess mate, but you may have the idle valve and throttle body position sensor cable connected up the wrong way round (easly done as they both have the same connectors on the cables).
Hope this is the problem.

Deano

[Dan320is]

On my car the idle valve has a rectangular plug and the throttle positon sensor has a round plug.

There are two plugs under where you plug the service light reset tool in, one is for crank position and the other goes onto the ht leads.

If these two plugs were put on the wrong way round could it have buggered the ECU?

[E30BeemerLad]

If Deano's suggestion does not cure it then look at the fuel pump, although there should be no reason for this to fail on account of the engine work you have done, it may be pure coincidence.

Brianmoore is your man to ask, but he had a problem on his hols whereby the car would start but as soon as you let go of the key from the start position the car died, fuel pump working when cranking the car over but failing as soon as the ignition swich moved to normal running position. Remedy was a replacement fuel pump or a strip and repair job if you are up to it.

But check the simple connections under the bonnet like suggested first.

[Jhonno]

timing is definately right yeah? not 180 deg out..

[Dan320is]

Thats definately worth checking.

When I was cranking it over there was plently of fuel. When I let go of the key it chugged for about 5 seconds, during these 5 seconds there was definately fuel being supplied to the fuel rail.


Could this be an ECU problem?

[325sportcab]

You must have a late touring as my 325i has the same connect on both but the later cars like yours have the circular plug on the postion sensors.
I'm no expert but i wouldn't think connecting the 2 connectors under the service tool plug would damage your ECU it would just be sending the wrong signal back and the car wouldn't run right.
Have you connected the all the air pipes up tightly and the rocker cover breather?
As Jhonno say could be timing out especally if the car is trying to run-on after you let go of the key.

[Dan320is]

Jhonno: I had the timing checked by 2 mechanic friends. If the timing is 180 degrees out would I be hearing bangs (valves & pistons hitting)???

And would it turn over if it was 180 degrees out???

[Dan320is]

325sportcab: I went round and checked all water and air pipes and I fitted a new breather pipe that goes from the rocker cover to the in let manifold.

I will check the air pipes again though?

If there is a loose air pipe would this cause the symptoms I've got?

My Touring is an '88 F.

[kam-325i]

it would still turn over, but yes, valves would be hitting pistons.....opening valves with piston at top of stroke when it should be at the bottom. ouch

[Dan320is]

Turning it over by hand and there wasn't any hitting etc.

It ran for nearly 10 seconds before I gave up at 11 last night.
It ran on its own without the starter but just chugged like it was only running on a few cylinders, it has spark on every plug.

????????????????

[Jhonno]

Jhonno: I had the timing checked by 2 mechanic friends. If the timing is 180 degrees out would I be hearing bangs (valves & pistons hitting)???

And would it turn over if it was 180 degrees out???

i dunno how much valve/piston clearance there is on the m20..

if there is enough, it might turn over iirc

best way to tell if there is valve to piston contact is to turn the engine over by hand n feel for any resistance

are all hoses connected up properly (no airleaks)

all electrical connections on properly

[E30BeemerLad]

one more wildcard entry from me, then I'll shut up and let the professionals take over..

Crank position sensor? Wired in/ mounted properly/faulty? Although maybe it would not start at all like someone had happen on their iS a while ago, poor bugger spent weeks tearing the thing to bits trying to find why it would not start, but I don't think it was starting at all, but he did have fuel at the rail and a spark

Sorry, I'm just throwing ideas in the pot here, so i'm probably full of shit

[kam-325i]

Turning it over by hand and there wasn't any hitting etc.

If you are turning it over by hand, you would "Feel it" hitting the vavles. thats a good sign then. phew

[kam-325i]

Jhonno: I had the timing checked by 2 mechanic friends. If the timing is 180 degrees out would I be hearing bangs (valves & pistons hitting)???

And would it turn over if it was 180 degrees out???

i dunno how much valve/piston clearance there is on the m20..

if there is enough, it might turn over iirc

M20 are interference(sp) engines, no clearence between open valves and pistons at TDC

[Dan320is]

Jhonno: I turned it over by hand, it only got harder to turn before the compression was released (heard it).

I took all the spark plugs out and turned it over by hand and with the starter and it sounded fine.

As far as I can see all connections air, water and electrical are connected.

[Dan320is]

Beemerlad: Crank position sensor is plugged in and is set close to the bootom pulley (toothed).

I think I might have another somewhere, something else to try.

Cheers

[x-works]

If you can get your hands on a compression tester and check the cylinder pressures that should rule out most mechanical things ie valve timing, valve clearances, headgasket etc,etc.
Some stupid questions here and I don't mean to insult by asking them but if the engine ran ok before coming apart it's most likely(hopefully) something straight forward thats the problem.
Are the fuel pipe's connected up the right way on the fuel rail (feed+return)
Is the TPS still signaling to the ECU that the throttle is shut at tick over.
Nothing fell into the airflow meter and blocked the flap while it was off the car?
Brake servo one way valves connected up the right way around.
There might be a broken wire in the loom after it was moved during the head removal/refitting.
Can you check the relevant pins at the ECU to see if the signal from the temp sensor is getting there (think its pin 45 on the 3 row newer ecu's)
and tps signal (pin 52 should be earthed I think)
Hope you get it sorted.

[oze30]

I might be a bit naive, but couldnt the problem also be from a lack of pressure build up ( compression in the cylinders due to a faulty gasket or something like that?

My old jeep I got back home had a similar problem. Found out it was just a wire that was sposed to be connected to the tacho, which I forgot to plug back up. It would turn over, run till the carb float was empty then die. Took ages and the auto eleccy didn't find it either!


Or what about a faulty/broken vacuum line?


Just a thought.

[Brianmoooore]

Timing exactly 180 degrees out isn't going to damage the engine!
When cylinder 1 ia at TDC on the compression stroke (when the spark plug fires), then number 6 is also at TDC with both valves slightly open.
If the timing is 180 degrees out, then in the example above, it will be no. 6 plug that fires, into an empty cylinder.
Can't be this though, as it wouldn't run at all.
Things that you can put back together wrongly are:
Timing belt a tooth or two out.
Fuel pipes wrong way around
Crank position sensor plug swapped with cam position sensor plug (the one from the pick up on ignition lead one).
Check and double check all the above first, then I think I would remove fuse 11 and put a testmeter set to an amps range in its place, to see what the fuel pump is up to.