Maiden Voyage! (down the driveway)

[Lester]

Well, I drove my S3, for the first time ever, even if it was down a gravel driveway. There were no brakes, and I thought it smart to stay off the roads. It was definitely a kodak moment. I have so many questions, but for now, I'll keep it to the most important. A previous owner, changed to a crane electronic ignition. The battery is installed Neg ground, and only the tach, speedo, and oil gauges work. It runs ok, but backfires quietly and often, occasionally through the zeniths. It has new gas, coolant, plugs, oil/filter. I had to replace the battery, but installed it as the old one was. When I would push the choke all in, or give it very much clutch, it would try and dog out a little. I'm thinking that maybe someone didn't correctly change the polarity. What do you all think? Could it just be cobwebs in need of a country drive? Thanks in advance, for all of your help.
Sincerely, Lester

 

[PaulK]

Congrats Lester,
I am anxious for that day to come to my garage.

Again, Congrats.
Paul

 

[Lester]

Thanks. That post was a bit wordy and confusing. Let me rephrase my question...Does this sound like an electrical issue, or a fuel supply issue?
Would it even run, if the polarity were switched incorrectly? I have a mess on my hands, but I'm determined to straighten it all out.
Thanks, Lester

 

[Alpine James]

I had my battery wired negative ground but everthing else positive for about a year until I noticed. Suppossidly it does make a difference but I couldn't really tell. To many other little thinks not quite tuned properly could also be the cause.
James

 

[bernd_st]

Hi there,

polarity should have no influence on engine performance, so would assume something wrong with the static ignition timing. Even electronic ignition it has to be set properly. Another potential cause could be mistaken firing order. Pls. make sure engine fires in the proper order - distributor turns counter clockwise.

Best greetings

Bernd

 

[ozzie alpine]

is it possible that the LT leads on the coil need to be swapped?

 

[Jim E]

Never owned a car with dual down draft Zs but the side draft 150s will do this if they are out of sync. Pull the choke and the car runs somewhat better sort of thing.

 

[Lester]

Jim E, Exactly. When the choke is half out, it runs quite smooth, but when I push it in, it starts to lose it. I have been suspicious about the zeniths since I got the car, but then I started reading posts about coil polarity and electronic ignitions, etc. I don't have enough time in this car to speak knowledgeably, but I am ready to have my daily (at least sunday) driver. So, I want to tune the zeniths...should I attack the valves first? And "Ozzie Alpine", could I cause harm by just swapping the leads on the coil, or should I go for it and see what happens?
Thanks, Lester

 

[Jim E]

I would
Time it
Adust the valves [need to do this hot and fast]
Balance the carbs

Then see where you are and go from there.

 

[Nickodell]

Lester, the choke and ignition have no connection with each other, and the only reason why the engine stalls without the choke in operation is that the mixture is too lean. My suspicion that this is the problem is strengthened by the backfiring. Backfiring (spitting) through the carbs is a very common symptom of an over-lean mixture. Backfiring through the exhaust is more commonly caused by ignition problems (intermittent spark allowing unburnt fuel mixture to enter the hot exhaust manifold), although it rarely can be a weak mixture - it's too weak for the plugs to fire but will burn in the exhaust. Both symptoms (carb/exh backfiring) can also be caused by burnt valves or broken/weak valve springs.

The only modifier to that is that a very strong spark - the kind only an electronic ignition system can provide - operating on wider than normal plug gaps, can fire a weaker than normal mixture (this is one reason that modern engines can wring the last drop of work from the fuel and get such great mileage figures). Since this doesn't obtain in your case you need to check all the things that could be affecting your mixture, starting with blocked jet(s) and working back to fuel pump, gas lines etc.

Sounds like an ideal opportunity to swap to a Weber.

 

[Lester]

Jim, Nick,
Thanks, I'll get right on it. I've never touched valves before, so you all know the extent of my mechanic exp. I do posess common sense and a workshop manual. If all goes well, we'll be trotting down the street this sunday. It may struggle, but it does run. I bought a Wilwood MC .7, and am putting it on this saturday. I know this is a good mc to go with for non-boosted brakes, but will it work with the booster?

 

[Jim E]

I have a .700 MC and a booster from VB and it is fine. The VB booster is a lower ratio than the factory unit but the odds of you having a good working factory booster are pretty slim. If you car has been sitting would just bite the bullet and rebuild the entire brake system and put new rubber hoses on it. Do the clutch MC and slave also.

When I adjust valves always rotate the engine by rolling the car forward with it in 2nd or 3rd. You can do this by your self by rotating the tire with your hands. I never put a socket on the crank pulley and never take the plugs out when adjusting the valves.

Would also put a see thru fuel filter on the car straight away so you can see the paint flakes from the gas tanks. Which is something else that most likely will need to be taken care of.

The other thing I would do is join triple A and get the gold card with 100 miles free towing. Bestest seventy five bucks I ever spent makes for real peace of mind.

 

[Nickodell]

Valves is the least likely of the possible causes. However, it's easy to check if any are burnt or seating badly. Get a compression gauge from Pep Boys etc. Remove the HT lead from the distributor and put a brick etc. on the accelerator pedal to keep the throttle wide open. Remove all plugs. Fit the gauge flexible hose into #1 plug hole and crank the engine for 10 seconds. Read the pressure, remove gauge and relieve the pressure reading with the button, and then repeat for all remaining cylinders.

You should get at least 120psi on every cylinder, even with a well-worn engine. 140 is better, 160 or higher with a new or freshly-rebuilt one. Just as important, the difference between the highest and lowest readings should not exceed 20psi. A very low reading (well under 100psi) on one cylinder indicates a burnt valve or incorrectly set lash (tappet clearance) preventing it from seating.

If you get uniform low readings, it can be either badly seated valves or worn pistons/rings/cylinder walls. Pour a tablespoonful of engine oil into cylinder #1 and repeat the test, also for the other 3. If the reading jumps 20psi or more, it was worn pistons etc. If not, it's valves.

To reiterate; try the more likely, and easier to fix, possible causes first.

 

[Lester]

Jim, Nick,
I really appreciate this. Where would a non-mechanic, with such a car, be without the internet? I'll check the compression this weekend and add the in-line filter this weekend and post my results. I'm getting comfortable with the idea of dealing with the valves and carbs, since I've been reading up on them in the manual. However, this after market crane ignition...I have no idea if it were set up correctly and if not, how to right it. The new ignition is hanging by zip ties from the washer fluid hose! ? Also, to reiterate, the backfires are primarily in the form of "pings" in the exhaust. I can hear them over the engine when behind the car. Maybe I should mention the exhaust is new and stainless.
Endless thanks, Lester

 

[Jim E]

Well while there may not be an issue with the valves.... I seriously doubt they are in adjustment. Have adjusted the valves on a bunch of these cars at Invasions and found very few to be correct.

The reason I say to adjust the valves is it can affect the tune and balance of the carbs. If the cylinders are not all sucking and blowing pretty much the same you cannot really get the tune on the carbs right. That and they are usually out of adjustment.

You want to do the valves and timing before the carbs, either one first does not make much difference.

 

[Steve Kirk]

I recently adjusted the valves clearances on my series 5 and the car does run much better.

I also had the rockers re-surfaced by delta cam and replaced the rocker shafts.

 

[Alpineracer8]

OKC, eh?

Lester:

I was surprised to see that you are from the OKC area. I live in Edmond and, while I don't have as much technical experience as I'd like when it comes to Alpines, I know plenty of folks who do. In fact, I'm just finishing up my '60 Alpine Series I vintage race car and have enlisted the help of several of these individuals during the past year. Contact me at awtiger@cox.net and lets talk.

Good luck,

 

[Bill Blue]

Nick, I don't understand the rationale of testing compression before adjusting the valves when you state that poorly adjusted valves can cause poor compression test results. Especially when misadjusted valves are very common. Its not like they are hydraulic or seldom go out of adjustment.

You just run compression tests for the fun of it?

Bill

 

[Lester]

Thanks guys! A wealth of information...if I only had a wealth of free time. If all goes well with the brakes, I'll check the valves tomorrow. What is the best method for novices tuning zeniths? I swear, one of these days, I'll run out of questions for you guys. Thanks, Lester

 

[ozzie alpine]

Hi Lester,
I'm not familiar with the crane ignition, but with a points system, I don't think that any damage can be done by reversing the polarity of the coil LT leads. If the leads are incorrectly connected the coil will still work, but may not be providing a decent spark (something to do with "collapsing the magnetic field" I'm told, but do not profess to fully understand!)
I did once incorrectly connect up coil wires when using my pertonix ignitor electronic ignition, with no damage done.