Yet another "won't start" thread

[billjam]

I have just refitted my engine after nine months of fiddling with it (see below) and it won't start.
It turns over OK and I have oil pressure and fuel pressure (haven't checked how much yet) but the problem seems to be that I don't have any spark until I stop cranking!
With a spare spark plug laying on the aircon mount connected to a lead, there is no spark at all until I turn off the key. Then I just get one spark as the ignition is switched off. The engine also gives a little cough sometimes as it gets its one spark when the cranking stops.

It has to be something simple, doesn't it?
I will start troubleshooting it tomorrow as I am off to bed shortly, but I thought I'd run this by you all first in the hope that someone has had a similar problem and can give me a hint as to where to start in the morning - otherwise I guess I'll just work my way through all the ignition electrics until I solve it.

I dropped the engine to fix a few oil drips and a stiff clutch. After catching "while I'm in there-itis", I finally put it back in today ...




Along the way, virtually everything got pulled apart and rebuilt (whether it needed it or not ) as well as a few additions like K27 7200 turbo, SC cams (at last!), head porting and polishing, B6 IC, Leask WUR, Raceware bolts, Innovate LC-1, LMA-3 and AFR gauge. It already had a Perma Tune elctronic ignition module.

[911nut]

Bill, is there a chance you accidentally fry the Permatune during removal (like if the battery was still connected)?

On a side note, how did the K27 fit up with the hole in the engine tin for the I/C hose when you put everything back together?

[rsrmike]

first double check the plug on the bottom of the CD box. They can be misleading and a real pain to fully connect. Sometimes I fold back the rubber boot just to be sure the plug is fully seated.

double check the other plugs in the engine harness near the 14 pin plug and the CD box, I think one is the power source for the CD unit?

Also check the green plug on the ignition distributor, and the wire going all the way to the cd box, if the plug is not loose.

I would also check the ground strap on the transmission?

Sounds like a wiring problem to me. Hopefully something just overlooked, or perhaps a poor connection in the engine harness that finally failed completely after all the fiddling around w/ dis/re-assembly...

I know you can check the signal from the trigger in the dizzy at the CD plug but I can't remember the best approach, seems like I used a sun-machine (ignition scope) back in the day, but perhaps a digital volt meter would work just as well?

[billjam]

Originally Posted by 911nut

Bill, is there a chance you accidentally fry the Permatune during removal (like if the battery was still connected)?

On a side note, how did the K27 fit up with the hole in the engine tin for the I/C hose when you put everything back together?

No, battery has been out of car right from the start, so I doubt that anything got fried. I am fairly sure its just a connection problem as Mike says. Its just a pain that everything is so hard to get at once its back in the car - I have been spoilt working on this engine for so long with 360 degrees access to everything!

Here I go hijacking my own thread ...
As far as K27 is concerned, the compressor outlet and oil pipes lined up in same position as 3LDZ. The only problem area is the exhaust side which is fatter - see pic.


I had to modify the turbo mount bracket and there are different ways of doing this. A common (and factory) way of doing it is to take a wedge of material out cut the bracket just to the right of the four holes and reweld. This retains the use of the top mounting point.
I wanted to be able to refit the 3LDZ if necessary so I opted to move the bottom mounting holes 20mm and not use the top hole.
I also had to shorten the exhaust pipe between turbo and muffler because I didn't have enough space for the muffler to move 20mm to the right.

Another area that needs attention is the compressor outlet pipe (up to IC).
I cut the top IC fitting off the original pipe and machined it to accept a 2.5" hose then used a 2" x 2.5" silicon hose reducer to connect from the turbo outlet to this fitting. (Actually, I am still playing with this connection and may go with a metal 2" x 2.5" reducer and two short hoses to connect the parts.)



Must get back to my car. I really want to go driving today

[billjam]

The two-wire connection to the distributor has a factory joint about 8" from the dizzy where it changes from two wires into one wire with a screen.
At this point, the insulation had given up inside the sheath (probably due to being moved around my shop for months) and the two wires were shorting - hence no timing signal from the dizzy to ignition module.

Don't you just love it when a potentially never-ending search just goes away in minutes

Just need to connect gearshift and put in some seats and take it for its first outing for nine months.
I'm just dying to see what effect all the mods have made to driveability and performance.

[rsrmike]

CONGRATS! Good find Bill.
Glad it didn't drive you nuts!

[WERK I]

Originally Posted by billjam

...........................Must get back to my car. I really want to go driving today

Congrats to you Bill! Way to stay with it!! Now if it would just warm up a bit, we could create our own joint global seismic experiment with our ground pounders!
Alas, it being 0 degrees F ( - 18 C) here, that won't be happening soon.

[911nut]

Bill, thanks for the info. That was very helpful.