Krel

Hi, so I just finished an intake refresh with also doing the timing belt and water pump. Car ran fine before the refresh, just had leaks at the top of the engine both oil and coolant, all the hoses were starting to crack.

Durning that I had the injectors cleaned and checked. Before they were really bad (140-200 cc/min), now all within 1% of each other at 240 cc/min.

Now that I have everything back to together, when I start the car, blows tons of white smoke and can't hold an idle. The idle runs away from me and then car dies with clouds of white smoke the whole time, the smoke dissipates very quickly ... pulled the plugs, they are fine.

Where should I start to diagnosis this?

928 GT R

My .02

1. White smoke is often a sign of a head gasket leak, sniff the smoke for the scent of anti-freeze.

2. Look for a plug that is cleaner than the rest or let it sit for a couple of days then remove the plugs and see if you get a bit of water or the scent of antifreeze when you have a friend turn it over- while watching for water being ejected from a plug hole.

3. A blown head gasket can let too much water into a cylinder - if it sits, water can collect in a cylinder and hydro lock your engine. This can crack the block or bend a rod! Be careful with it until you diagnose what is happening.

545svk

A fuel injector stuck open will also give you white smoke..

Petza914

What does the smoke smell like - coolant, oil, or gas? Is the engine slow to crank the next day? Any glugging sounds after you shut it off?

Mrmerlin

First what year is your car how many miles
have the head gaskets ever been replaced?

NOTE before your next start ,
best bet pull the spark plugs and inspect the cylinders with a bore scope,
look for small puddles of coolant.
also post a picture of all the plugs.
NOTE if any oil was sprayed into the cylinders during the refresh and you have factory cats,
then large plumes of smoke will come out the tailpipe till the engine has run for more than 15 mins.

davek9

When you pull the spark plugs, take the time to run a compression test too.
Recently had a friend ask me to assist in finding a miss-fire, (also had smoke out the tail pipe).
The compression test reviled 30PSI in cyl #8, 1985 so pulled the engine and his heads are currently at the machine shop.

He had just done the exact same thing, T-belt and intake refresh in-order to solve the miss-fire.

Krel

1986 with 86,400 miles ... do not know if the head gasket has been replaced, no record of it. I've only had the car 2 months but got it knowing I needed to do the refresh and timing belt/water pump.

I will get a scope and check the cylinders via compression test.

Will post once I get to it.

Thanks everyone.

Mrmerlin

NOTE if you see a visible decrease in your coolant level then the chances are good the coolant is going into a cylinder,
if so I suggest to not start the engine ,
but rather follow my previous post , this so you dont bend a rod or crack a cylinder by Hydrolocking the engine.

Krel

I was just refilling the coolant after the water pump replacement, so it might be hard to know if that's air or going into the cylinders at this point. The plugs might not be a great sign either since they were replaced just before trying to start the motor for the first time after the work.
I'm just surprised that I would not have seen this before I started the swap and refresh. Given the smell of the exhaust and unable to get to idle ... I'm thinking more and more it's a stuck injector. But I will pull the plugs and start checking things.

There were the plugs I pulled at the start of the timing belt replacement before installing new ones to try starting the motor this weekend:

davek9

3rd from bottom looks to be different (brighter) and the ground strap is spot on clean

Petza914

Yep, and it looks like the white insulator has a tinge of color, maybe blue or green. If you were running that color of coolant, definitely remove that plug and look in the cylinder bore.

Krel

Well I will scope tomorrow to be 100% sure, but looks like cyl 2 and 3 are wet. My question would be why was there no white smoke before the refresh and now it's a ton? I was having an oil and coolant leak at the water bridge and oil filler, where was a soup sitting in the valley of engine.
So is the only solution to pull the motor do to the head gaskets? Or could I drop the engine from below?

Mrmerlin

its too hard to tell from your last picture.

what we are looking for here is one or two of the plug insulators to be brand new looking,
like it has been steam cleaned, also you could see rust forming on the tip of the electrode.
thats if it is burning coolant.

All this said scope the cylinders,
what color is your coolant?
how long has the engine been run since you performed this work?
NOTE it can take 15 mins for oil to burn off in the cats,
this oil can come from residuals that might have washed into the intake ports then into the cylinders while you were working.

Krel

So the first set of plug pictures were the old plugs I pulled when I started the refresh. The second picture is the new plugs just after trying to restart (I would get the engine to run for about 10 sec with lots of smoke and then it would die). So the engine has not been running since the work, this was my attempt to restart after doing the work. I did not put any oil into the cylinders during the refresh. Here are scope pictures after the motor has been sitting for the last day and a half ... I think I need to try to restart again or is there a procedure to turn the engine over without fuel being sent to injectors to see if any coolant is being pumped in? These correspond to the ones that came out wet (2 and 3).