M42 is loud and shakes after maintaince

[JayK]

Hi All, '91 318iS with an M42, car has abut 300K km on the clock. Ran fine -although a bit hot- until I opened it up, now when I start it, its loud and shakes pretty bad. Sounds more like a tractor than a car :/

Stomp test gave me the 1444 code which I read online means no issue.

List of what I've done to the poor thing since the last time it ran:
-New VC gasket
-New profile gasket
-New cam sprockets
-New timing chain
-New crank sprocket for timing chain
-New lower chain guide
-New front crank seal
-New crank bolt and spacer
-New OFH gasket & O-ring
-New sparkplugs
-New belts: AC,PS,water/alternator
-New thermostat and water pump (81C was installed, replaced with the 84C)
-Coolant flush and oil change

I removed and cleaned:
-Both timing cases (they were covered in oil/grease I think they were probably contributing to my cooling problems)
-Valve cover
-Intake plenum
-TB and heater plate
-ICV
-AFM/airbox

I'm pretty sure I've re-connected all the hoses, and I'm at a loss as to what the problem(s) could be.

Any and all help is greatly appreciated, thanks.

[Captain_Birdseye]

I'm no pro, sure Brian will offer some concrete advice soon. I wonder how is/was the chain guide? You didn't spot any 'bits' in the oil when you changed it, for instance?

[JayK]

No solid bits, but the general area had black particles in the oil, which I'm assuming is nylon dust from the rails being worn down. No bits of chain rollers or other metal. The old chain was fully intact.

After starting the RPMs sit around 800 for a few seconds before dropping and the car wants to shut off. I checked the resistance of both the cam and crank sensors and they agree with what I've read online.

I had removed my TPS when cleaning the TB, I re-installed it carefully, but could this be related to my problem?

[BHadley]

Did you change the tensioner also?
Check the zone wiki I think it is covered in there under dieseling

[Topblag]

In the work that's been done there's a lot of scope for getting the timing out of whack.

[JayK]

Did you change the tensioner also?
Check the zone wiki I think it is covered in there under dieseling

Yes, the tensioner was done about 5k ago.
Couldn't find dieseling in the wiki :/

In the work that's been done there's a lot of scope for getting the timing out of whack.

True, however I made a cam lock out of wood, and had the pin in the fly wheel until everything was buttoned up.
I did notice however that notch on the crank pulley was not aligned with the arrow on the OFH at the point in the rotation where the pin slid into the flywheel, not sure if that' normal.

[JayK]

UPDATE:

I removed the ICV, and it doesn't pass the shake test. Looks like it might be jammed closed. The vane looks about 2mm from being fully closed, using two small screwdrivers I can "walk" through a bit of rotation into a more open position (this means I walk it through fully closed before it opens), anyone know what I'm talking about?

Can I join the ICV in & out hoses without the ICV installed to see it idles, is this an ok method to test if the problem is the ICV?

I had cleaned it with TB/Brake cleaner when it was off the car, could I have damaged it?

[JayK]

UPDATE:

Compared my ICV with a good one, the good one doesn't rattle when I shake it all... mine rattles a little. This isn't what I've seen online which is weird.

Replaced the intake elbow and made sure all hoses were seated right. The bottom one connected to the TB heater had come off and the area is wet with coolant. Reconnected it

The car now holds it idle without wanting to shut off, but its still a rough idle.

After running it until it was hot and approaching over heated, I shut the car of and heard an air hiss from the rat's nest under the intake, not sure what that means.

And of course, it wouldn't be an M42 if it didn't tick/rattle - which it does

I guess the next step is to adjust the mechanism on top of the AFM. I'll update this thread for anyone who's following.

[Brianmoooore]

Late to this one! My initial thoughts were cam timing, but now it looks like it's simply not idling at sufficient revs, although there's not sufficient info. given.
Is the problem just a poor idle?
Does the car drive OK, once off of idle?
What RPM is it idling at?

Any hiss you can hear is water or fuel coming out, or air going in, and needs to be sorted before going any further.
DO NOT adjust anything that has never been adjusted before. All the adjustments were correctly set at the factory, and do not need adjusting again. If adjusting anything improves performance, then all you are doing is providing the opposite to whatever an unknown fault is doing.
The solution is to find and correct the unknown fault, not introduce a second fault, that will cause problems when the original fault is cured at some point, either by accident, or by necessity when the fault develops further.

[JayK]

Hi Brian thanks for your response, yep the issue is a poor idle, I haven't driven it yet, just started it up after doing the work.

I observed that the idle was smoother if not good after the car was warmed up compared to when it was cold. I guess I have an open loop issue and the ecu compensates for it in closed loop?

While cold, it idles around 800 which is rough but not horrible, however it sort of pulses and dips down to 700/750 and shakes pretty bad. If I bring it up to 900 its pretty smooth.

I stopped myself from adjusting the AFM after reading your reply.

I think the hissing was a from a coolant line, or air escaping from the cooling system while the engine was hot, because the tone changed after sometime and I think this was because it started sucking air in through the same leak as the fluid cooled...

Operating on the thought that it was a hose leak I took the plenum off once again, and hose clamped every line I had touched. I added about 4 clamps -all around the TB and TB heater. Started it -after about 5 days- and it idles pretty rough around 7-750