Mike,

Probably not the head gasket - a gasket that was blown badly enough to totally kill all four cylinders is very unlikely, and would almost certainly show other symptoms, such as a fountain of coolant from somewhere!

Some possibilities:
Bad injector harness killing the injectors. Use a stethoscope to listen to the injectors - there should be a steady clicking as the engine runs. There should NOT be any clicking with the ignition on and the engine not running.

Faulty cam timing.
A compression check will tell you if this is a possibility.

This could be from the intake cam timing being off on the belt. Check by setting the engine crank on TDC ( 0 ). Look thru the cooling air spouts atop the belt covers, and try to see a very small notch on the back of the sprocket that lines up with a cast mark on the backing plate. Check both sides. If you can't see the mark on either side, turn the engine one full turn back to TDC and check again. You should see the timing marks on both sides.

There could also be a problem with the exhaust cam chain. The intake cam is driven by the belt, and the exhaust cam is driven by a chain in the center of the cams. This is not a common trouble spot on the 928, but it is on the very similar four-cylinder engines for some reason. You would have to pull the cam cover to check this, but a compression check will tell you if that is a possibility.

Good luck!

Steve,

This is probably the difference between a wiring schematic and a pictorial representation of the real thing. Mike's car should have the decal that I quoted on the front header panel, but they are sometimes missing.

The wiring schematics aren't too much help in physical placement of the wires sometimes. I can look at the schematics and see how the headlam system works electrically, but it doesn't help with where the wires really hook up, for example.

Some of the wiring diagrams are good, but some really suck. The entire set for the '84 models for example - they don't even show the wire colors, and are totally unusable.

It is good to see you contribute! You have some special skill and experience that are extremely valuable to the group.

 

You need 3 things to get fire in the hole. Air / fuel / spark.

Air is easy....... if some cylinders are firing, the engine is getting air. Short of having inhaled a bird or some other obstruction. You can look past the air-filter to the screen in the MAF just to be certain that it's not full of debris....... it wouldn't be the first leaf to have made it past the air-fliter housing.

Next easiest to check is spark. DO NOT just pull wires off the plugs. This high-energy ignition system is both dangerous and delicate. If pulling wires doesn't fry you, it might well fry the igntion part of the LH-brain which, in your car, is all in one unit. Rather, find one of those "inductive pick-up" timing lights and go from one plug-wire to the next.

Finally, fuel. This takes some finesse or experience, or special tools, or all of the above. First, listen to each injector when the car is running, they should be "clicking" pretty distinctly. You can get a loooonnnngggg screw-driver and place the metal tip against the injector-body and your ear (firmly) against the handle, or get a mechanic's stethoscope. You could pull spark-plugs and look for wet plugs, also.

That's all it takes to get the fire lit. Smooth is quite another issue!!

Don't forget, your car is the first year that the LH brain has the diagnostic feature. You can pull the codes for this information if you can lay your hands on the code-reader. Some 928'er in the Gtr TO area must have access to one.

 

Wally,
It is a pleasure for me to contribute to the group. I think every one who contributes should get a free lifetime member ship. <img border="0" alt="[hiha]" title="" src="graemlins/roflmao.gif" /> Thank you very much for the compliment.



<img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

 

Steve,

The main problem with that is that we ALL contribute sooner or later!

I think that it is great to watch a new owner start by asking some really simple questions, and three months later, he is answering questions for the newbies!

I'm afraid that if no one who contributed paid, Mr. D. would be doing this for free - until he ran out of money.

 

Hello again all and thank you so very much for your advice.

I have checked the power to all injectors and it is the same. I then listened to all the injectors via a long flat screwdriver butted to my ear (this works very well actually). I could then clearly hear that all of the injectors were functioning fine (or so it would seem).

I then checked the TDC marks on driver’s side cam sprocket. With crank at OT the recess in the cam sprocket was as it should be (WSM).

I then re-checked the gaps on the plugs, they were fine.

There was a big difference in the condition of the new plugs. As I wrote before cly #'s 2,3,4 were the only ones firing. The plugs were :

1 clean
2 light soot
3 light soot
4 soot with a small bit of oil

5 clean
6 small amounts of carbon
7 oil
8 a little more oil than 7

So wire connections, spark, and fuel seem fine.

It is Easter long weekend here so no chance of a compression check today or tomorrow. So if there are any other helpful suggestions I would be very appreciative. If not I will pursue a compression check on Tuesday, and then check the exhaust cam chain (thanks Wally).

Best regards,
Mike