Help setting timing on '89 volvo 740 GLE with 16v engine

[Larry Bumgardner]

This engine apparently is timed automatically. After doing a major repair to it, I found the engine backfires after reinstallation. I had dismantled the engine and repaired the crankshaft.

After putting things together and back in the car, I found that there are no ignition breaker or timing wires coming from the distributor. It only distributes high voltage to the spark plugs. Everything is clearly marked.

I noticed a special magnet and sensor associated with the flywheel and I now suspect that I should have installed the flywheel so that the sensor/magnet was aligned when at top dead center on cylinder 1. I didn't do that. I just bolted the flywheel back on with no particular orientation. The flywheel has 8 bolts. I seriously doubt that the computer can correct for this mislocation of the mark so far from where I suspect it was intended.

I have tried reordering the spark plug wires so that they keep the same firing order, but begin with a different plug number. No dice. The best setting is the original, but it seriously backfires and simply will not start. The engine behaves as if the timing is too far advanced.

Am I going to have to pull the engine and reset the orientation of the flywheel to match cyl 1 to the timing marks???? Any ideas? Am I right about what triggers the firing order?

Any help sincerely appreciated. My Chilton's makes no mention of the mark on the flywheel. Everything simply says it is computer controlled and will self-adjust.

Larry Bumgardner
Durham, NC

 

[James Sweet]

This engine apparently is timed automatically. After doing a major repair to it, I found the engine backfires after reinstallation. I had dismantled the engine and repaired the crankshaft.

After putting things together and back in the car, I found that there are no ignition breaker or timing wires coming from the distributor. It only distributes high voltage to the spark plugs. Everything is clearly marked.

I noticed a special magnet and sensor associated with the flywheel and I now suspect that I should have installed the flywheel so that the sensor/magnet was aligned when at top dead center on cylinder 1. I didn't do that. I just bolted the flywheel back on with no particular orientation. The flywheel has 8 bolts. I seriously doubt that the computer can correct for this mislocation of the mark so far from where I suspect it was intended.

I have tried reordering the spark plug wires so that they keep the same firing order, but begin with a different plug number. No dice. The best setting is the original, but it seriously backfires and simply will not start. The engine behaves as if the timing is too far advanced.

Am I going to have to pull the engine and reset the orientation of the flywheel to match cyl 1 to the timing marks???? Any ideas? Am I right about what triggers the firing order?

Any help sincerely appreciated. My Chilton's makes no mention of the mark on the flywheel. Everything simply says it is computer controlled and will self-adjust.

Larry Bumgardner
Durham, NC

I hate to break it to you but if it does indeed use a toothed wheel on the flywheel then yes you'll have to pull the tranny again to align it properly. Hey at least now you know how to do it.

 

[Peter Milnes]

You will have to realign the flywheel correctly as the ignition timing is critical on this engine. There are diagrams available to give you the correct alignment.

Cheers, Peter.

This engine apparently is timed automatically. After doing a major repair to it, I found the engine backfires after reinstallation. I had dismantled the engine and repaired the crankshaft.

After putting things together and back in the car, I found that there are no ignition breaker or timing wires coming from the distributor. It only distributes high voltage to the spark plugs. Everything is clearly marked.

I noticed a special magnet and sensor associated with the flywheel and I now suspect that I should have installed the flywheel so that the sensor/magnet was aligned when at top dead center on cylinder 1. I ...