Need Help Diagnosing Engine Stutter
Thread Starter
Pro
Joined: Feb 2001
Posts: 558
Likes: 0
From: Dallas TX
Need Help Diagnosing Engine Stutter
Hey folks, I need help diagnosing an engine stutter due to a fuel or ignition system problem. When I get on the car full throttle in 1st gear, the car will kinda stutter at around 2000 rpm's, then continue about every 500-1000 rpm's until I shift at 6000. I replaced the distributor with a new unit, new spark plug wires, the spark plugs are about 7 or 8 months old. Here's my assumptions. Either I have too much timing, it's set at 33 degrees total right now, my spark plugs fouled out because the pickup coil in my old distributor was bad, my carb needs some rebuild work, or my coil is going out. My coil is an Accel Super Coil, and it's been on the car for about the past 6 years, 4 of which, the car was sitting in a garage, never started. I have a brand new spare coil that I might throw on to see if that fixes it, but I'm just looking for some help on this. Thanks in advance folks...
Safety Car
Joined: Feb 1999
Posts: 3,631
Likes: 14
From: Fountain Hills AZ
Could be either. Lean jetting on the secondary side? 33º total is on the low side if you have stock type heads (36-38 is closer to ideal) but your symptoms are more like too much or too little timing. How did you set the total timing? At what rpm does your new distributor reach max centrifugal advance?
Thread Starter
Pro
Joined: Feb 2001
Posts: 558
Likes: 0
From: Dallas TX
Around 3500-3700 RPM's, my advance is maxed out. We set the timing base timing with the vacuum advance unplugged and capped, then we set the total timing by running the engine at 3500 RPM's, dial on the timing light set at 33 degrees, and turned the distributor until the timing mark on the harmonic balancer lined up with the zero on the timing plate. I was always under the assumption that running too much timing (ie. 39 degrees) was bad if the engine wasn't able to handle it... I was actually considering retarding the timing a bit. I'm taking the car to the track tomorrow, bringing a brand new coil I have laying around, a distributor wrench and a timing light. I'm going to try and tune it between passes to see what happens. It also SEEMS like this only happens when the car is hot. When I'm just cruising around town, and I start out hard from a stop light, there's no stutter. But when I've been hot rodding it for a while, then get on it, the stuttering is prevelant. I'm confused... 
