rough running SC

Alan L · Alan L's Garage

Well, after about 4 months I finally got my rebuilt motor back in the car. It did start reasonably easily, and no leaks and no strange noises. Perfect. Almost.
It is running rough - not on all cylinders. But what is most weird is the speedo is behaving like the tacho. I have not hooked the drive universals up yet, and basically the wheels aren't turning. It is still on jacks. But both the tacho and speedo move together.
So, I'm hoping the rough running is electrical, but can't work out what I might have screwed up.
What does the tacho drive off (it is working fine), and more importantly, what is the speedo driving off.?
Thanks
Alan

Eagledriver · 08-05-2006, 10:58 PM

The speedo is probably moving because you have the tranny in gear and the drive shafts not hooked up so the output shaft is turning.

The rough running could have many causes. First things to check are ignition related. Plug wires hooked up correctly, spark plugs installed tightly, faulty plug wires, faulty cap or rotor.

After you run it for a few minutes you can pull the plugs and see which ones are wet (not firing).

-Andy

Alan L · Alan L's Garage

Thanks Andy. Yes it ocurred to me after that the little pick up on the side of the g/box is probably my speedo drive, and the selector rod probably knocked back when installing engine.
Will have to go back and check basics. Worry about valve timing - but I did check it all again after setting it, and it was spot on for both sides. Then, as per Waynes book, I increased the valve closure by 2mm on both sides and turned it over with no contact.
I can't imagine if the cam timing was out enough to cause this, I would get so much valve clearance.
Each exhaust outlet is hot, so it seems to be firing on all. But the symptoms are like 2 crossed plug leads. But have checked them too.
Back to basics I guess.
Alan

AFJuvat · 08-07-2006, 06:27 PM

You just did a full rebuild on a CIS motor. Go back to basics with your fuel injection. You will probably have to reset idle, mixture, CO and timing.

Double check all of your electrical connections on the fuel injection system, double check all of your vacuum lines.

AFJ

Alan L · Alan L's Garage

AFJ is correct.
I checked everything - fearing valve timing, or wrongly set valve clearance on one or two cylinders.
Could find nothing wrong. Checked spark on all leads - all fine.
So, concluded it could only be the settings. Leaned the mixture off a bit and fiddled with the timing while the engine ran - this is its first fire up since complete rebuild - so only static timed. It is still up on jacks. The timing hit a sweet spot and the engine now runs beautifully, tight, quiet, no leaks. So far , so good.
Thanks
Alan

dick911 · 08-08-2006, 06:37 AM

Check the water level in your battery... (yes, this reply seems strange...).

In the past I noticed the same... Battery water was too low, peak voltage by the regulator caused the moving needles.

fill up the water and that solved the problems...

Good luck,

Dick911

azasadny · azasadny's Garage

Alan,
So the timing was the culprit? I'm doing some CIS troubleshooting and I'll be rechecking everything this weekend. I'll recheck my timing...

Alan L · Alan L's Garage

There are many things that could be wrong with the CIS. But mine was working fine before I pulled the engine apart.
But it would certainly pay to check the timing first - you want everything else eliminated before pulling the CIS apart.
What are the symptoms?
Alan

azasadny · azasadny's Garage

Alan,
My car stumbles and misses above 3000rpm and something seems to be holding the engine back. My mechanic tells me my timing is fine. I replaced my plugs and plug wires, coil, rotor, cap, WUR, etc... and am still having problems. I'm going to test my pressures tonight and see what the results are.

Alan L · Alan L's Garage

Does it do it all the way beyond 3000 rpm, or just in a band.
If it is all the way, sounds like fuel starvation/imbalance.
Either not getting enough fuel, or the air plate may be sticking - not opening all the way.
You can check that one simply with air filter off, and lifting plate gently - feeling for tight spots. I induced that once by leaving my tuning Allen key in the mixture control unit. The plate opened enough to give me about 4500 rpm and them hit the wall.
Alan