Spark, Fuel and no start

[plainside47]

HI,

I have a 1989 Beretta 2.0 L. The car would start and run rough for about 2 min and then die because it had no spark. Then it would not start at all. Replaced the crankshaft sensor now I have spark again but it wont start, it acks like the timing is off, it backfires through the intake, will not even fire. Has good fuel and has spark. What to check now??? this has me stumped! How could the timing get off? Ran compression and all are around 155 or so. If timing was off then cmpression would be low right?> Spark seems to be erratic more than anything.

Thanks.

[maxwedge]

Gas soaked plugs, crossed wires, bad ign module, all are on the list of suspects.

[plainside47]

Thanks for the response! I have used many plugs to check for spark. I have tripple checked that I have put the plug wires back onto the coils in the correct order and they are labeled on the coil and the wires also. Is there any other sensors besides the crankshaft sensor that I should look at or would the next thing be to replace the ICM? Would a bad ICM cause irratic spark? Thanks.

[MagicRat]

Backfiring through the intake is a classic sign of bad plug wires (spark energy is jumping from one wire to another because the insulation is breaking down) or valve timing that is off.

Valve timing can be off but still let the engine build good compression in some circumstances.

Try new wires first.... if no luck, take a look at the camchain gear set to make sure the timing points are lining up properly.

[rhandwor]

Place the engine on TDC look at the rotor button and tell us where it is sitting. You may have jumped a tooth on the gear.
Did you use an ohm meter and check the plug wires?

[J-Ri]

Use a spark tester to check spark. Under compression it is much harder for the spark to jump the gap in the plug than it is at atmospheric pressure. Set the tester to at least 20 kV, that's the minimum, these coils in good condition will jump between the towers on the coil packs which is about 10x farther than the 20 kV setting. If the wires are numbered, that means they are probably the factory wires. They could still be good, but I'd change them just for peace of mind. I do them with every tune-up. The CKP sensor is the only sensor used for spark timing. The ICM can cause erratic spark, but if you have spark when you're testing it, it should start. I'm not sure about the 2.0, but the 2.2 has a timing chain tensioner that has a plastic/composite shoe over it that can fall off and cause the timing to jump around. While I have not seen that personally, I have read about a couple of them on here.

EDIT:

Originally Posted by rhandwor

Place the engine on TDC look at the rotor button and tell us where it is sitting. You may have jumped a tooth on the gear.
Did you use an ohm meter and check the plug wires?

'89 uses coil packs, no distributor here.
Checking the wires with an ohm meter doesn't say if they're arcing to ground or not. With presumed factory wires, they need to be replaced anyway.

[rhandwor]

My electrical one line diagram shows a normal coil with the center post going to a distributor cap for a 2.0L port fuel injection 1987 to 1990.
I don't know what your looking at. (Product Research Manual)
http://www.rockauto.com/ It shows a cam sprocket and a crank sprocket with no chain.

[plainside47]

Yah the car has 2 coil packs one pack for 2 plug wires...I just dont think it could be valve timming when the car died and it showed no spark on the plugs. Then put in a crankshaft sensor and now there is spark..I cant think that the valve timming and crank sensor went out at the same time. Plug wires look ok. no worn through spots and they still seem rubbery. If I am getting compression it should still run rough if it is just valve timming right?

[rhandwor]

Advance and Auto Zone will check the module for free. Backfiring I've found is caused by a broken plug core and it jumps a gap and fires. I've found many loose terminals on plug wires poor factory crimping. Cracked valve springs and jumped timing also cause backfiring.
A plugged air cleaner will cause a no start.