The Oldsmobile Connection

[Rick87]

My 1981 98 Regency "diesels" whenever I use anything less than 92 octane gasoline in it. What I mean is, if I use regular gas, when I shut it off after a trip the engine won't stop, and cylinders will fire sporadicly, sometimes for minutes.

Any ideas on a fix, besides the obvious "don't use regular gas?"

[andrewk]

Check your timing, and check your timing chain.

Olds used Nylon timing sets in these engines to reduce noise. What usually happens to these gear sets as they wear, is that pieces of the nylon break off, or the timing chain jumps a couple teeth, causing either very advanced, or very retarded timing.

To check it out, check your ignition timing, and also check the position of the rotor in reference to where #1 cylinder is at TDC, compression stroke. The rotor should be just about at the post for #1 plug wire. If this is off by much, and you haven't been messing with it, it's probably good cause to check the timing chain.

Welcome to TOC-
Andrew

[Rick87]

OK, thanks for the reply, I will check it out. Honestly, I had not considered this as a fix. Thanks for shedding some light.

[88 Coupe]

Hi Rick87,

Welcome to TOC.

Quote: ........ "diesels" whenever I use anything less than 92 octane gasoline ........
Premium should be required for your 307. If so, retard the timing 2° (more if needed). But, be aware, that you will lose power and fuel mileage by doing so.

Norm