missfire, HG problems? solved! page 3

[dubownerbilco]

so i have got my conversion up and running

but just having a couple of issues:

when cold the engine is fine and will rev without a problem but as it warms up the missfire becomes more obvious and almost undrivable past 1/4 throttle. i fitted a speedtouch chip and let it tickover for ten minutes as instructed and this made no dfference

also after having a brief drive in the car and letting it tickover for a while i noticed that the coolant hoses were rock solid and were visibly larger! all the hoses are connected as per the guide and i bled it without a problem :S

neither of these were issues when the engine was still fitted in the 5, as i used it for a week prior to removing the engine

any ideas people?

thanks in advance

[zaust]

Cylinder leak test, coolant pressure test and get the coolant checked for exhaust gases.

[jimbom30cab]

would a compression test help ? easy to do and a usefull test also, compression testers are cheap enough to get or free if you can borrow one.

[dubownerbilco]

Got a compression tester already, but as i said this wasnt a problem before removing the engine from the 5, so i would like to think me connecting the hoses incorrectly would cause the pressure?

[leeparkes]

Are you getting any typical head gasket symptoms, ie mayo on the cap on the dipstick etc?
M30's can be a bitch to bleed, there's a guide on here somewhere on the best method.
I think Bristol_Jer wrote it.

Jerky driving could be a number of things, got a multimeter?

[dubownerbilco]

nope no symptoms of HG

i did think it seemed abit too easy to bleed :S i just kept pouring it into the expansion tank with the bleed valve open and the heaters on hot until i got no more bubbles from the bleeder and that was it! when i ran the engine the coolant level didnt go down any more so left it as it was

and yes i have a multimeter, although ime stumped if i know how to use it! electrics arnt my strong point, i can follow simple instructions and just about manage though, give me a spanner anyday

[dubownerbilco]

so i replaced the blue coolant temp sensor this evening, which did actually seem to help and the missfire certainly doesnt seem as obvious, although it is definetly still there...

i was checking out the TPS however, and it clicks when you first move the throttle, but not again on full throttle, is there a particular way of calibrating it?

[zaust]

It only clicks the once on m30. As you move the throttle is spot on.

[dubownerbilco]

ok fair enough

[zaust]

Do the leak test will tell you lots.

[dubownerbilco]

How would i carry out a leak test?

But again none of this was a problem before removing the engine so it just has to be something simple that i disturbed during the swap?

[Bristol_Jer]

Can you post up pics of where your coolant hoses connect so we can see if they are right? As you said they may be fitted wrong?

http://www.e30zone.net/modules.php?name ... c&t=228676 for bleeding, BrianMoooore added a bit that simplifies the process further down the page

[dubownerbilco]

I re bled the system according to that tonight aswell, and after 20mins of ticking over you could hear the coolant tank cap hissing and the hoses were rock solid again!

I shall take some photos of the hoses first thing in the morning

[mcbonio]

How are you cooling the engine? Are you sure it's not on the verge of over heating?

[dubownerbilco]

How are you cooling the engine? Are you sure it's not on the verge of over heating?

Ime using a brand new e28 m30 rad, so its pretty big!

And surely 20minutes isnt long enough for an engine to get to the verge of overheating?!

[Rav335uk]

Did you replace the thermostat???

[mcbonio]

If it's not got a fan blowing on it and its sat there idling away for 20 mins it will overheat.! Have you connected the brown temp sensor to get a reading in the instrument cluster?

[dubownerbilco]

I currently do not have a working temp gauge, i am getting the correct sensor from a friend tomorow, and no i have not changed the thermostat...

[mcbonio]

You got an electric fan set up yet?

[dubownerbilco]

You got an electric fan set up yet?

Not yet, i am working on it though...

I have a twin fan setup i salvaged from a breakers yard that i am yet to mod to make fit. I know the fans are obviously needed for day to day use, but just 20 minutes ticking over from cold cannot be enough to bring an engine to overheat??

[mcbonio]

Yep it can, there are lots of folk post here "my car is overheating when sitting in traffic" which normally transpires that their viscous fan isn't locking up and needs replacing...

When you drive along the cool airflow through the front of the car aids in cooling the radiator, when it's stationary this doesn't apply, if you have no fan then the coolant temperature will continue to rise.

Your radiator cap begins to hiss and release pressure when the water reaches a certain temperature (can't remember what it is, someone chime in) this increases coolant pressure, and you have no way of measuring temperature so how do you know how hot it is?

You need to get the electric fan set up and using a 91c thermal radiator switch and get your temperature gauge working before using the car again, or you'll be doing a head gasket job.!

[dubownerbilco]

Thanks for the advice!

I am not actually using the car yet, still just getting it ready and ironing out the last few problems

Now onto curing the misfire...

[leeparkes]

If you say you bled it religiously and there's no other symptoms of it being a headgasket failure then id put money on it being the stat, if the stat is stuck shut it will be even harder to bleed plus it will get hot quick, ie 20 minutes.

Take it out and test it the old fashioned method.



Do it on the cooker in a pan of water with the gas on.

[dubownerbilco]

Top man! I shall also have a go at that

[mcbonio]

Or you could just touch the bottom radiator hose to see if its hot after a few minutes of running?

[leeparkes]

True.

[dubownerbilco]

Its definetly hot! I did actaully do that last time it pressured up

[Rav335uk]

I would not be running the engine for 20 mins or so without a fan setup, you don't realise how hot these engines get, plus the engine bay is a lot tighter round the M30, so less heat dissipation.
Get the fan hooked up, ook into the stat, only a few £'s to change over for a piece of mind.
Then start it up, get the brown temp sensor in to keep an eye on theengine temp too.

[dubownerbilco]

took some photos of the hoses this morning

top of rad to stat housing to bottom matrix pipe



bottom of expansion tank to stat housing to top matrix pipe

[mcbonio]

Looks ok chap.! I still think your engine is starting to overheat when the hoses are rock hard and the expansion tank is hissing.! As Rav says, these m30s get hot quickly, especially when running stationary.

I would not be using this car until you have a fan setup and monitoring the temperature. !

[dubownerbilco]

Right then, i have a working coolant temp gauge now

I am seriously starting to think i may have a Headgasket failure on my hands?

1. pressure in the coolant system
2. Missfiring when warm
3. Abit of white smoke from the exhaust

compression test results:
cyl 1 - 150
cyl 2 - 160
cyl 3 - 160
cyl 4 - 170
cyl 5 - 170
cyl 6 - 175

is it possible it could have just started to go on cylinder 1, which would mean when its warm the gap opens up and starts to cause the misfire which does get worse as it gets hotter and then also starts to over pressureize the coolant?

Also, what should happen when i disconnect the fuel pressure regulator vac pipe, as the revs just rise slightly and it behaves no differently when revv'd

I still have the 1.6 fuel pump, could this cause a problem not delivering enough fuel?

[mcbonio]

Compression looks ok, no1 looks a tad weak.

All M20s and M30s have white steam coming from the tail until it warms up. Does it constantly have white steam even when hot?

Do you have oily gunk in your coolant bottle? Is your oil creamy, and cream on the oil filler cap?

[dubownerbilco]

Compression looks ok, no1 looks a tad weak.

All M20s and M30s have white steam coming from the tail until it warms up. Does it constantly have white steam even when hot?

Do you have oily gunk in your coolant bottle? Is your oil creamy, and cream on the oil filler cap?

the white smoke does die down alot once up to temp, and no, no and no

[mcbonio]

Have you checked all ignition components? Visual inspoection on Dizzy cap, rotor arm, plugs, leads. Measured resistance on HT leads.?

[dubownerbilco]

Dizzy cap and arm looked slightly corroded but not excessive, leads are slightly deteriorated around the plug boots so i wrapped them with insulation tape for good measure for the time being, i have a spare coil i can try also.

I do intend on giving the engine a full service, but ime sure you will be aware of the costs involved part wise for an m30...