Hi all. I’m having a starting issue with my Pantera that has me baffled. I’ve had the car since 1992 and it’s never left me stranded. It’s been running strong and starting immediately including right before this situation. Last weekend I started a drive with a planned stop at a pet supply store near my house on my way out. So, the car started just fine at home, warmed up a bit and then drove perfectly the ½ mile to the pet supply store. I turned the car off, bought dog food and then got back in to continue my drive. Well, the car would not start. It turned over fine, the battery was strong, the starter was cranking but it would not start seemly like it couldn’t get a spark. I pulled the air cleaner and could see that it was getting fuel as the fuel would squirt in the carb when I gave it throttle. I thought I may have flooded it so I let it sit 15-20 mins and tried again. Same issue. I pulled the driver side rear most plug wire and hooked up my spark tester. It showed spark just fine. I let it sit for an hour. Same issue. It cranked fine, would sound like it wanted to fire but would not. Even when I floored the gas pedal while cranking it (like for a flooded engine) it would rev up very high like it was running but would not catch to keep running. I then pulled all the plugs and cleaned them with parts cleaner I had with me. They looked dry but black indicating they were carbon fouled which was probably from me trying to start it over and over creating a rich condition. So I ended up getting it towed the ½ mile back to my house on a flatbed. : ( The next day when home I did the following (stats on my car listed at bottom of mail):
- Checked fuel coming into the carb. It was fine
- Changed to all new spark plugs. I checked for spark and it was getting spark at the plug just fine. I gapped the new plugs at .054 based on research on this forum and other Ford sources for a 1974 351c in stock condition with an electronic ignition. The one I tested showed good strong spark.
- Pulled distributor cap and it looked fine as did the rotor. They are both about a year old.
- Turned rotor to see if it spun freely (e.g. roll pin may have sheared). Rotor would not turn by hand so I assume it was still connected through the shear pin (did check it later though)
- Changed carburetor to the new Summit Racing carb I had recently purchased since I did notice my really old Holley 600 was leaking fuel at the base plate area. However it was running fine and strong before I pulled it but it may have been running rich based on reading the plugs. The new carb had fuel squirting so looked good. Figured since I had spark, that maybe there was some issue with the Holley. Same symptoms with the new carb….didn’t start in the same manner.
- Pulled front engine cover to check static timing. Cranked the engine by hand via the crank pulley and moved it to show the timing mark (16 deg BTDC) on the timing marker that I had set last year. The distributor rotor moved just fine to point to the #1 sparkplug wire location at this timing. This tells me that the distributor shear pin was probably fine and the timing chain is still keeping things lined up
- Still had the same issue of not starting with the same symptoms
- Pulled the distributor to check to see if the roll pin sheared or partially sheared. It looked perfectly fine. I did notice the inside of the distributor where the magnetic signal is captured and the metal wheel that rotates with the rotor to align to the sender from the ignition box was had some light surface rust. But since I had spark at the plugs it must still be working fine. I cleaned it up anyway while I had it out
Stats on my Pantera:
- Late model 74
- Stock basic 1974 engine with 32K miles and never rebuilt
- Stock oil pump and fuel pump
- Edelbrock performer aluminum intake manifold installed nearly 30 years ago
- 600 CFM Summit Carb with electric choke and vacuum secondary (same as the Holley set up I just took off)
- Duraspark 2 electronic ignition/distributor (bought from Hall in 1993). Mine has the green plastic colored wire support coming from the control box. I wonder if this has failed?
- New MSD coil (not the oil can type). Bought this about 4 months ago and it was working great. This is MSD, P/N: 8207 that is one of the coils Jon Haas (Pantera Electronics) recommends for his system. I did have a oil filled coil fail in the past and that was easy to diagnose and replace. This new MSD coil made the engine really run nice!
- Stock starter which cranks just fine
- New battery (about one year old) which is strong, charged and cranks fine
- Standard stock grounds throughout the car. I did clean up the braided ground by the end of the transaxle as part of general maintenance a few years ago
So I’ve been going through the normal FASTEC approach. Fuel, Air, Spark, Timing, Exhaust, Compression. It has fuel, air, spark, and timing. Compression hasn’t been checked yet but it’s a low mile engine which was running super strong. I think a compression issue would have shown up with some symptoms rather than running great one minute and not starting the next. As far as exhaust that is working and not clogged up in anyway. I’m at a loss here as to what it could be and why it ran great one minute and wouldn’t start the next. Next I’m thinking the Duraspark 2 box may have failed. Not sure if those fail in a mode where you get spark at the plug but the timing of the spark is off due to the box failing? Any suggestions are appreciated. Thanks, Mike
P.S. I sent this to the DeTomaso email forum as well to get additional input. I really want to get driving again : )