[JohnB]

It did it again. Very frustrating. After 2 weeks of running great, took the daughter out for a ride last night to celebrate father's day. Got back in the car after an hour and the exact same symptoms as last time. Plenty of spark and fuel but it won't run.

I guess I'll be running through the same diagnostics as last time this happened but this time I'm going to work on it myself.

Pointers accepted, there may be an open garage session this Saturday if I don't get very far on my own.

[type954]

! there is a device called a "noid" which is a little light connected to the FI connection to indicate that the fuel injector is "firing". if you have fuel and spark... ???

i bought a FI tester on ebay that needs to see a first use, one of those Bosch testers. you're welcome to use it. unfortunately, i'm out of town fri-mon. fortunately, i'm out of school as of this morning. unfortunately, (for all who read this and think how lucky i am), there is no paid vacation. fortunately, .....

[JohnB]

Jim,

PM me your phone number and I'll call you. I'm in MD today but will be headed back to VA this afternoon.

I read the old thread and can't understand how a CHT sensor would let the engine run at all if it was bad. Since the car only fails at start-up after the engine is warm I'm guessing at looking at things that change with heat. The car sat for many hours last night and cooled off completely. It wouldn't start even then but I'll be giving it a crank again this evening.

Thanks, Jim

[Richard Curtis]

When you say the car has "spark" what color is the spark? If you're checking for spark by grounding a spark plug on the block and observing that you get a spark, you need to look for a blue spark. If the spark is any color other than blue, you've got a weak coil. Hope this helps.

[JohnB]

Richard,

Good question. I think it's yellow (had the wife look while I was doing the cranking, she's not comfortable in a std shift car) but I'll see if I can get a better read this evening. The last time this happened the observer said it looked yellow. As long as you got spark, is the color significant? Won't they all ignite the fuel?

I pulled the coil line from the center tower on the distributor and laid it close to the engine tin to see the spark. The car was tuned up less than 1000 miles ago and has a new rotor, condenser, spark plugs and ignition points.

Since this problem hasn't stopped the car once it's running, this is an interesting and frustrating problem. Both times this has occured on low humidity days, mild temps and warm but not hot engine (temp guage in mid-range prior to shutting it off).

Thanks for your thoughts.

[Richard Curtis]

Blue spark is the hottest. I've known cars with yellow, orange or red sparks not to start. When we raced enduro karts, the color of the spark was always the tell-tale for when the ignition coil was bad. It's always worked for me on cars also. Dunno what the cost of a new coil is, or whether your existing coil can be tested, but I'm betting you need a new coil.

[JohnB]

Good tip and worth a look. Coils used to be around $15 or so.

[BillJ]

Yeah a bosch Blue coil is around $25. If the CHT sensor is bad the car will not start at all. This happened to me at the track - not fun - and not your problem unless the wire is frayed and maybe loosening with heat and/or connecting irratically? Sounds like a dying coil though!

[JohnB]

Thanks, Bill.

If the coil was dying, why wouldn't the car just quit on me somewhere as I'm driving along?

john

[oneblueyedog]

I seem to remember the distributor has trigger points to fire the injectors. How are those?