Expert: Sean Halliday - 10/6/2006

Question
Car has 185,000 M, did comp. test, 145# on three cyl 95# on 4th. is there any way to tell if the timing chain has jumped w/o removing the cover? do you know if the codes will display if the ecm has been changed and the car not started? we changed plugs and ignition coil assy, still no start. valves seem to be moving normally this is a tough one!
-------------------------

Followup To

Question -
Have 91 beretta 2.2 throtlle body FI Drove car home, saw some odd fluctuation in the instrument cluster. Engine ran poorly, almost died at idle.
Checked fuel flow,(ok),checked spark,(ok), Egr,(ok), crank pos. sensor,(ok), Jumped pins a&b in the diagnostic terminal, only code 12 flashes. Changed the ECM, no difference. The car has a timing chain, (no belt) but I don't know how to tell if the timing has changed?. Took off the rocker cover, can't see the timing gear etc.

Answer -
Code 12,no tach signal system normal.It means there are no codes on the memory so i think you may need a tune up and check the fuel pressure/regulator,it may be your PROM, if fitted.On this car the timing is set so theres no adjustment as it has DIS,the chain may be worn but the computor allows for the adjustment in the spark advance.I would also have the ignition module tested.You didnt say how many miles are on the engine,did you do a compression test for worn valves?

Answer
Theres no way to tell unless you remove the cover.Why did you replace the ECM?..Rare for these to fail,more likely the PROM if fitted.95 psi on one cylinder isnt good enough to run smooth so looks like a valve job is needed so that takes care of the timing because you will have to remove the head.Is the igniton spaking at all?.If you have spark and fuel then its either timing or compression.And changing the ECM from another car isnt recommended.I think they are not compatible.You might want to check with the dealer.