my 1988 745Ti has fuel and spark, cranks slow and won't start. The plugs are sooty black. I was told it needed a timing belt when I got it. Where should I go from here?

Thanks

Richard.

Did timing belt break or was it just due for replacement? Look into oil filler cap while cranking and observe if cam is turning.

You will have to deal with the slow cranking problem. Slow cranking indicates low voltage to the starter, if voltage is too low ignition and fuel systems will not work. Is battery just run down? Have you charged it? Can you check battery voltage while cranking? Try boosting with another battery and determine if you have normal cranking speed.

Sooty black plugs could indicate a problem but you must have engine running first to diagnose that.

You are correct to determine that you have spark and fuel. Can you say exactly how you checked for fuel delivery and spark at the plugs?

Not sure what the model 740Ti indicates. Is this a B230 engine with turbo?

Hi Dave

The timing belt is just due for replacent,it's in there though. The cam s turning when cranked.

I tried starting the car with a new battery, it cranked faster but still didn't fire.

I had a friend check for spark by holding a screwdriver in a plug wire very close to a ground while I cranked it. I checked for fuel by disconecting a line to the injectors and cranking. The engine also floods while attempting to start.

The car was basically free, I paid what I got for a car I sold that I coudn't drive anyway. So, I don't mind taking my time working it but the bod and interior are in such good condition compared to my 245 that I'm getting impatient.

The 740Ti is just an intercooled turbocarged 740 with almost the same exact engine as the B230 turbo in 240s, it just has different details and a larger turbo. This is why I like the car so much. Aside from it being familiar mechanically, the 745 body and interior are a significant step up from the 245. I still love the 245, but really, the 745 is VERY nice!

Thanks for the advice! Without it running at all I wsn't sure what direction to go in.

Tanks again

Richard

Why not clean up those plugs. Just because fuel runs out of the line does not mean it is able to build pressure up to the required 35psi or so. The intank pump by itself will pump strong enough to spew fuel out at the disconnected line. Better check to make sure the main pump is running.

Plugs hve been cleaned, I even put a new set in. I'll check the fuel pump if I find an extra set of ears to listen for me. I'll deffinately be checking the starter conections to.

Thanks

Richard