erratic engine

[jmattox]

This weekend at Daytona we encountered what seems to be an unusual situation. Car was prepped and "ready to go." (unfortunately by me) We made the practice session. Could only get engine to 5k rpm on backstretch and tri-oval. We (I) had just recently timed the distributor @ 3000 rpm approx 30 degrees advanced. We then could not get the engine to run over 1k rpm @ full throttle. We changed; spark plug wires, distributor and fuel pump. No luck. We put the car on the trailer after consoling ourselves on the beach and an Italian dinner and drove back to Tampa. Then we (I) discovered that we (I) had used the wrong timing mark on the pulley. Maybe problem solved and on to Sebring Oct 18,19.
My question is: Could a distributor out of time by "a whole bunch" support the 5k rpm run I had during practice and then sometimes "work" and sometimes not work? In other words do I have something else wrong somewhere else? We have run the car two other times @ Daytona and Sebring with relatively good results.

John
FV 42

[Cooper 64]

I am not the one to ask but I have heard that a coil can keep the car from running over 5000 rpms
just my 2 cents

[jmattox]

My bad,I misspelled coil. We did not replace the distributor we did replace the coil.

FV 42

[billinstuart]

If your mechanical advance was sticking, it could cause the problem described. you did get the polarity correct on the coil? Tach on the proper terminal? Is the engine misfiring/backfiring or just terminal lazy? Swap distributors with someone. Timing should be 35-37 degrees TOTAL, all in by 3000 or so. Forget initial timing..mark your pulley at 36 degrees (1/10 of the circumference) and go from there.

Oh yea, make dead nuts sure you have TDC marked ACCURATELY.

[jpetillo]

I just had a situation where the car will completely misfire above 5K, and it got worse the longer I was out.

The suggestion was to first check the battery soon after coming in - before it has time to recover. I had it on the charger, so it went out for the 20 min session at full charge. After coming in it was at 10.6 V - not enough to run the ignition at high RPM - so that was it. Another thing, even at 10.6 V, the car starter would spin the engine just fine - so the engine starting is not an indication of enough voltage to run the ignition.

After that the car misfired above 5700 or so. We swapped the distributor out and that solved that problem. It's probably just a bad set of points, but I had limited time to test individual components to see what it was.

A coil can also cut out when it gets hot, but I think it's a lower probability.

[jmattox]

I think the biggest problem was the timing marks on the pulley. I think I timed it at 3000 rpm square on number one at TDC. So timing ended up retarded by 30 degrees or so. One of the marks was crystal clear and the other one had a black mark on it. I chose the unmarked one and timed the engine at 3000 rpm. That was before the weekend at Daytona. I think the battery crapped out about the same time, the starter ate its bushing and the wreck racer fords were eating vees. I don't think that was the weekend to race! Maybe we will have better luck in October and at the Turkey Trot in November.

Thanks to all who helped.

John
FV 42

[billinstuart]

Two other things to consider. COILS are either internal or external resisted,,make sure you have the correct one. The resistor actually reduces the voltage and current to the points, preventing "burning". CONDENSERS are prone to failure..they are simply capacitors, that degrade with time. If your points are burning evenly, DON'T replace the condenser. In fact, don't replace the points either.

"If it ain't broke, don't fix it"

[SR Racing]

John,

You want your timing set to 36 deg advanced (that is what should be marked on the pulley) at above 2000 RPM. Also when timing rev it beyond 2000 and make sure it goes to 36 and stays there without falling back again.

The pulleys are often marked at 0 and ~36. You can always tell the difference because it will idle faster when you have it set at the correct mark. (When idling though it will be in the 10-15 deg area).

Yes, if you really had it 30 (or 36 degrees retarded), it would severely limit any high RPM.

In regards to it "sometimes "work" and sometimes not work", not likely a timing problem. (Unless you have a defective distributor) This is possible since the newer 009's are junk. (both Bosch and Chinese knock-offs.) The sleeve that the mechanical advance press fits to can slip. This will cause as much as a 20 deg change in timing dynamically. It might be close at one moment then off later. We initially thought this was a Chinese knock-off problem, but it turns out it can happen on all of the newer units. (Bosch or not).

Jim

[smsazzy]

Replace your battery. I replace mine every year, as they are cheap and seem to go bad quite easily. (Especially if you use a small one for weight like I do)

I had a cell short out and it would not rev past 5 grand. It would rev up just fine, until it reached and then it sounded like it was running on 3 cylinders.

Very frustrating as it happened during a race.

[jmattox]

I think my crew chief needs to learn how to do mechanicing. We replaced spark plug wires, coil, fuel pump and battery and had a really nice weekend at Daytona. The beach was nice, we found an Italian restaurant that we thought was closed, the weather was perfect and everybody had a good time. We just didn't race. The "crew chief" insisted that the timing was "right on." Just because he used the TDC mark for 30+ degrees advanced at 3000 rpm.....
Things are going MUCH BETTER at Sebring this week.

John (half time crew chief)
FV 42

[brian]

A few thoughts regarding high speed misses. The greatest probability for our cars is that the points have closed up. Always check the dwell before setting the timing. If you do not have a dwell meter, use a .016 feeler gauge. Second, check all your plug wires for continuity. Wires break down and will cause missfires. Third, check the plugs and see that they're light in color and dry. If you have one bad looking plug, and your sure the wire is ok, check the compression. As far as coils and condensors are concerned, it's actually very rare that they fail and should be the last thing you look at. Sometimes bad coils will cause the tach needle to fluctuate. Next, I have never, in 50 years, seen a battery that can start a motor not run the ignition. With that said, if you are running computers, video, dvd's and maybe a fridge on your car, all bets are off. Seriously, Jim can tell us the actual numbers, but the ignition takes hardly any voltage. Finally, if you hook up the coil wires backwards, not only will the car not start, you'll smoke a set of points in a NY second. Think of a dead short going through that little wire on the points. Bar-B-Q time guys. Sorry you missed a weekend of racing but never hesitate to ask your fellow vee folks for help.

[SR Racing]

Brian is pretty accurate in all he said.

In regards to the battery being a problem. Highly unlikely. If it starts the engine, it can supply far more than enough to fire the igntion. We put a car on the chassis dyno and loaded the battery down with a carbon pile pot. The engine ran great and never lost 1 HP until it got below 9V. A 9V lead acid battery for all practical purposes is DEAD. The only time I have seen a battery cause a miss is with loose connectors.

Jim

[NotMoss]

I can add to Jim's comments that as a result of a loose battery terminal and an unexplained (until after a lot of troubleshooting) dead engine coast up to a flag stand two laps from the end, we added "Battery Terminal Tightness"
to our checklist.

[FV80]

Don't forget to consider the MASTER SWITCH in the process. In my own case, I got one with a key that wasn't 'right'. It BARELY made contact in the ON position (but I didn't realize it). After having it 'flip' itself off on 2 occasions (during races), I pressed IN on the key and found good contact. Then, I finally thought to try a different key - it was night and day different. MUCH more load as I clicked the switch - a full positive connection and no trouble since. Seems the 'key' part of the key was positioned a few thousandths too close to the end. I also routinely spray a little brake clean in there and flip the switch multiple times as I blow it out with air ... to keep dust and grit from building up inside.
Steve

[jpetillo]

In regards to the battery being a problem. Highly unlikely. If it starts the engine, it can supply far more than enough to fire the igntion. We put a car on the chassis dyno and loaded the battery down with a carbon pile pot. The engine ran great and never lost 1 HP until it got below 9V. A 9V lead acid battery for all practical purposes is DEAD. The only time I have seen a battery cause a miss is with loose connectors.
Jim

Like any system, it's a combination of things. An otherwise perfect ignition system may run fine with a bad battery as Jim pointed out. But bad plugs may not tolerate the reduced spark voltage from a low battery, but run fine otherwise. The same with bad wires. In my case it was bad points (well, I swapped out the whole distributor and the last of the problems went away - guessing it was the points).

As my battery drained down from 12.8 to 10.6 V during a run, the car would first skip at 5700+ RPM, and by the end of the session it could barely muster 4500 RPMs. When I put in a good battery, it would still skip, but only over 5700 and it would stay that way - I could at least drive the car and keep up with others. So, the low battery certainly had a huge effect (at least with the bad points). Otherwise, I never had seen a car misfire due to a low battery in 50 years either. But a low battery in a Chevy won't start the Chevy. Although my 10.6 V FV battery would spin that bug engine over just fine - I tried it!

Like everyone is saying, there are a lot of parts to the ignition system. I'd first check for bad battery connections (switch's too), then points, then plugs/wires, etc. But low voltage is pretty easy to check for, and if the car's not running right and the voltage is dropping too fast, I'd replace the battery. It may get you through the weekend, even if you can't quickly identify what other parts are failing.

John

[Rickydel]

I had a race at Lime Rock in my FF, when the car started easily and would run fine on the track except around corners.
We chased fuel feed and ignition problems.

It turned out to be a battery that was short circuiting under load. After we changed the battery, it ran like the Energizer Bunny.

[jmattox]

Thanks for all the suggestions. A course in "crew chiefing" would help most, I think. We raced at Sebring this past weekend. Completed most of the sessions. Ran into a braking problem and fixed the dry rear master cylinder by filling it up. Will look for possible leak before the Turkey Trot in November. The short course at Sebring is hard work, but the correctly timed vista worked like a charm. Now, on to driver improvement...

John
FV42