OK, I have a 89 RS 305 TBI. The only mod is o.e. air cleaner. This just started the other day, I get on the freeway and it starts studdering. Not at any particular time either. Whether I'm at WOT or low RPMs it does it sometimes. It's really bothering me, and it does not throw a SES. Any ideas as to what the heck is going on???? Thanks!

 

Does it run a little warmer than ususal? If so check your catalytic converter.

 

No, it runs at the same temp. it always does.

 

Ignition high voltage...

Check your rotor, cap, plug wires (especially the coil wire), coil, and plugs. It's possible that if you look at the ignition system in total darkness withthe engine running, you may be able to see where it's arcing.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

does it backfire?

check the wire that goes from the negative battery terminal to the body. mine cracked inside and my car was backfiring and shuddering really bad.

took me forever to find out what was wrong...

later

jon

[This message has been edited by sunbound (edited October 08, 2001).]

 

I will check the rotor tonight, no back firing, and no other problems at all. Thanks, and keep the suggestions coming.

 

check the fuel filter and the rest of the fuel system I.E. fuel preasure make shure the regulator is not siezed in the more closed position.

 

I would suspect plug wires, or ignition component. Start it a night in the dark and look for arcing. If its been a while replace plug wires and distributor cap/button anyway. Nothing like a tuneup to cure problems.

[This message has been edited by brharris27370 (edited October 09, 2001).]