My 91’ 740 with 217K miles takes anywhere from 2 to 10 seconds, usually closer to 10 seconds, to start. It needs a little throttle and runs rough for another 4 or 5 seconds and then runs perfect. This began last Winter and I have yet to figure out the problem. I have a wrecked 90’ with the same engine, ignition, etc. and have been swapping parts from it. The wrecked car ran fine until my daughter rear-ended a truck last fall so it has some good parts. I have swapped the FPR, Regina ignition module, two fuel pump relays, Air Mass Meter, rebuilt the distributor (new seal and O-rings), replaced the dist. Cap and rotor, installed new ignition wires and plugs (Bosch WR7DP), replaced the fuel filter, and yesterday replaced the fuel pump with a new one. Tonight I put the timing light on and found there was spark immediately, but it took 10 seconds to start running.

So, I need help badly in diagnosing this critter. There are no error codes in the diagnostic module (forgot the correct name). Could the problem be dirty injectors? I tried a couple cans of Techron Injector Cleaner last Winter and didn't notice any improvement. The car is driven in a rural setting so it doesn’t idle much or run at slow speeds stop and go. I did notice last Winter that gas from one station gave slower starts than from another. My guess at the time was low vapor pressure from the station the gave slower starts, but then I was getting desperate as I am now and may have been imagining things!!

I also have another 91’ with the identical engine, etc. and with 158K miles. Last week it also started getting slow to start. It is not my imagination either because my wife and kids are afraid to go anywhere in the cars. One common thing that is making both cars run badly may be the gas, but how realistic is that? The gas turnover in the several stations is quite fast.

Any help would be appreciated.