MSD Ignition or Weber Carb Issue?

[SpyderMike]

Thanks for the info Randy - I appreciate it!

Mike

[Chuck]

Ryan and I went for a 40 mile ride this evening - longest single ride to date. Turned off the fuel pump a bit less than a quarter mile away from home. Let it idle a bit after getting into the garage. Then shut it down.

Not a hint of boiling, dripping or sizzling fuel from the carbs.

Good tip!

[RichardH]

bit of a dumb Q - but what are the symptoms of this - because my engine has suddenly decided to run like a dog

symptoms are :------
popping in carburettor.
turning over but not firing
turning over then "siezing" as if it is firing on the compression stroke
taking 20 mins or so to start
sounding like it is running on 4 or 5 (ish)
running fine for a while
stalling at junctions

or can any of you give me any other pointers? I am hoping to do a compression test soon and check static timing. Understandably I dont want to run it any more than I have too.

Or is there anyone close to Basingstoke (Hants UK) that has the equipment - coz my compression tester wont reach thru the exhaust pipes and I have never statically timed a 302.

[Dave Peterman]

I have seen the gears fail on a 351 windsor. I jammed oil pump broke ours mid race. A retaining clip from a lifter popped out and the oil pump sucked it in through the center hole in a stock pickup.

[Jac Mac]

Wouldnt still be mobile[running] if it was dizzy gear--- if its got a Holley my guess would be power valve ruptured, has it backfired thru carb recently, if so its probably stuffed. Fit a check valve in PV channel in base of carb to help prevent this in future if you find this is the problem.

[dfreeman95]

Those symptoms sound very close to what we had on a fresh 347. It was indeed the distributer gear wearing prematurely. Apparently the engine builder had a batch of distributors made and the shaft lenght was just a bit long so it was eating the gear. Initially the car just seemed to lose power and had a bit of a misfire at higher RPM. It didn't take long until it was backfiring through the carb as well and seeming like it had started crossing wires. We ended up going through a couple of gears and a couple distributors and a complete removal of the engine to check for damage (none was found) before we got the problem resolved.
Check the power valve first as it is the easiest but if that isn't the culprit pull the distributor and take a look.

[RichardH]

Originally Posted by jac mac

Wouldnt still be mobile[running] if it was dizzy gear--- if its got a Holley my guess would be power valve ruptured, has it backfired thru carb recently, if so its probably stuffed. Fit a check valve in PV channel in base of carb to help prevent this in future if you find this is the problem.

It has backfired recently - several times in fact. Yes it does have a Holley.

Erm - sorry to show my ignorance here, but .............

what does the power valve look like?
where is it fitted?
what is a check valve and where can I get one?

Sorry folks - but I dont really know these things in detail - I just enjoy driving it (normally).

and thanks.

[Frank]

Put a timing light to it.

[Dean Lampe]

If it is relitively easy, I would pull the valve covers and check the valve train. That is one of the first things I do when I'm not sure where to look. Just to make sure there isn't something bent.

[Mike Drew]

The symptoms you describe sound *exactly* like a distributor gear problem. And Jac Mac, over the years I've been around at least a dozen different distributor gear failures (none of them mine thankfully!) where the failure wasn't sudden and complete, but rather gradual and confusing; the car suddenly started running badly, but it continued running. (I've also been around a few failures where they suddenly quit stone dead, like somebody had just taken a poleax to the entire ignition system).

The two main types of failure are failure of the gear itself, and failure of the shear pin which attaches it to the driveshaft.

Fords use a gearrotor-style oil pump, which is basically two gears meshing together and squeezing oil through the system. Debris in the engine (deteriorating gasket, valve stem seal, excess silicone sealant, etc. etc.) can become trapped in between the gears and momentarily cause the pump to jam. When this happens, usually the shear pin does its job and snaps, and the gear is free to spin on the shaft, and the car simply stops dead.

But sometimes the jam is so momentary, and the gear is a press-fit on the shaft, so that the pin snaps, the gear rotates on the shaft and then grabs, and then the car continues to run, although the timing is now grossly retarded. Suddenly the car runs like crap, overheats etc. etc.

The other failure is simply one of the gear wearing out. Steel roller cams required a soft metal (bronze) distributor gear, which has a known sub-5000-mile lifespan. Just last year I helped bail out a Pantera whose owner had bought the car recently from an estate. It had a completely killer engine whose specifics were unknown, built to the hilt as a 'race motor' including 'race' parts, including a sacrificial distributor gear. The guy drove the car about 2000 miles without incident, then drove it in one day from home in Oregon down to central California where I and a handful of friends met up with him enroute to Las Vegas. The next day, it started acting up, and would barely run.

Eventually we managed to get it started, but it didn't have enough puff to negotiate the slight hill of a driveway. After fiddling with it for a couple of hours, we pulled the distributor and discovered that the gear was totally worn away. What was happening was that the timing was free to jump around, perhaps plus or minus 20-30 degrees from the proper setting?

The motor had almost exactly 5000 miles on it at the time.

Whether you've got a bad gear, or just a bad pin, I'm fairly confident you'll find that your problem is located there.

Just FWIW, Comp Cams has introduced a new whippy-dippy distributor gear within the past couple of years, that is an upgrade from the standard cast iron gear, with three times the lifespan of a standard bronze gear. Here's the relevant page from their catalog:

http://www.compcams.com/technical/Ca...106-07/235.pdf

Alternately, I've also seen the same problem caused by a timing chain that jumped one or more teeth. The stock Ford timing chains use cheap nylon gears, which have a finite lifespan. When it jumps teeth, you check your timing and find it drastically retarded, so you rotate your distributor and it's "fixed"--until it jumps again.

In any case, it sounds like a timing issue of some sort.

Good luck, and let us know what you find!

[LloydGT40]

Another suggestion is check the floats on the holley. I just had an o ring go on the needle valve. fuel was dumping into the carb. Big sign is a lot of black smoke.
Timing light will tell you if you took out the distributor gear
LLoyd

[RichardH]

Originally Posted by Mike Drew

Just FWIW, Comp Cams has introduced a new whippy-dippy distributor gear within the past couple of years, that is an upgrade from the standard cast iron gear, with three times the lifespan of a standard bronze gear. Here's the relevant page from their catalog:

http://www.compcams.com/technical/Ca...106-07/235.pdf

Has anyone tried these?
Are they as good as they say?
A bit of feedback would be appreciated before I consider getting one.

[Trond]

Hi

As mentioned, use a timing lamp to check the timing first. That is easy and quick to check.

I have also experinced timing gear trouble, BUT it was not the gear i self that was the problem. The locking pin (dont know if that is correct neme for it) that fixes the gear to the disributor axle broke. At first in a way that made the gear rotate on the axel a bit, and the locked.

First I just adjusted the timing one more time, thinking that the distributor it self had moved out of position. But the next day the gear loosened totally an the engine would not run.

If your timing has gone wrong, take out the ditributor and check the gear/locking pin.

Regards
Trond

[Grady]

To answer your question "what does it look look like?" Cheap to buy and easy to replace.....
Grady

[RichardH]

Thanks - but I am in the middle of a carb strip and rebuild.

Arent the rebuild kits from Holley rubbish? Bags full of bits with no identification - its a guess which bits fit where .

[RichardH]

Carb now rebuilt - new Compression tester arrived today, so its go check distributor ond compressions next.

[Kalun D]

Originally Posted by RichardH

Has anyone tried these?
Are they as good as they say?
A bit of feedback would be appreciated before I consider getting one.

I'm running one, they have to be broken in with non-synthetic oil, seems to be working okay so far but only 250 miles.

the oil pump/distributor drive is a weak point in these motors, the shaft is too thin

When building my motor I was going to go with a high perf oil pump and was advised against it because the drive shaft barely supports the stock pump.

[Mike Drew]

Originally Posted by Kalun_D

The oil pump/distributor drive is a weak point in these motors, the shaft is too thin

When building my motor I was going to go with a high perf oil pump and was advised against it because the drive shaft barely supports the stock pump.

I presume you're talking about a high pressure pump, not a high-performance pump. A high-performance pump (that is, one of higher quality than the cheap made-in-China pumps you can find at your local auto parts store) is a much better choice. But you're right--there's no really good reason to run a high-pressure pump. 40-60 psi is more than enough, and anything more just puts unnecessary strain on the cam and distributor gear, and the oil pump driveshaft.

The stock shaft is of so-so quality; it's a fairly standard procedure to replace it with any of the much higher quality units available from Ford Racing, Canton, ARP, Melling and others. They are generally considered to be far superior, and they're cheap as chips!

A quick look at the Summit Racing website shows 37 (!) choices to suit any flavor of Ford motor you'd care to mention!

Ford oil pump driveshafts

[Jack Houpe]

Originally Posted by RichardH

Has anyone tried these?
Are they as good as they say?
A bit of feedback would be appreciated before I consider getting one.

Richard I put one of these (composite gear) in my motor when I installed it in the car after 3800 miles I pulled it out to check it before my Big Bend Open Road Race week after next. it has signs of wear on one side of the gear only, not totally bad but enough to replace it. I replaced it with a bronze gear. I will see how long this one last. If I ever pull my engine I will install a belt drive external pump and do away with these problematic gears. I will post pictures of the gear today and wear.

[RichardH]

Well!!! is it good news or bad?
Have checked and rebuilt the carb - with NFF

Removed distributor today. Piccies attached below. Although there is some wear on one side of the teeth, maybe sufficient to replace it after the 3000 or so miles it has done, all of the teeth are intact and the drive pin is also complete - checked by looking thru roll pin ).

So - what are your comments? I repeat the symptoms.........
popping in carburettor.
turning over but not firing
turning over then "siezing" as if it is firing on the compression stroke
taking 20 mins or so to start
sounding like it is running on 4 or 5 (ish)
running fine for a while
stalling at junctions

I intend to fit the distributor back (for the time being) whilst a new gear(s) is on its way from the states, so that I can carry out a compression test. It is looking, in my eyes, more like stuck valves or HGF (although I cant see why HGF shud happen over winter.




The saga continues...