Hard Starting 74 2.0

[pcsanady]

I recently purchased a 74 2.0 with Webber 40 carbs. When the car is cold it won't start on the first turn of the ignition. It is more difficult to start as the temperature drops, taking up to ten turns of the ignition before it can be driven. After the car gets going there is a lot of hesitation and surging until it gets warmed up. Once the car reaches normal operating temperature it runs great and can easily be restarted.

I have tried having the carburators adjusted, pumping the gas pedal before starting, etc. Any help would be greatly appreciated.

[Dave at Pelican Parts]

Welcome to the wonderful world of carbs.

I am told that there is at least one Weber carb that has a cold enrichment device to help with those problems, but I don't know which one(s).

You could try something to monkey with the fuel pressure depending on temperature, but that would probably be a real chore and pretty hit-or-miss. And I haven't heard of anyone making such a product already, so you wouldn't just be able to buy something and install it.

You might also try to set up a hand throttle like the 914-6 came with. But from the sound of it, that is also an expensive chore. (The throttle linkage from the pedal to the throttle cable is actually quite different, you see, and pretty rare.)

Or, you could convert to fuel injection. The stock system has several parts that are designed to help cold starts and cold running. Or, if your engine is non-stock enough that the stock FI won't work well, the better-quality aftermarket setups have some provision for changing the mixture with engine temps.

Please note that I have an anti-carb bias, and that probably affects what I'm telling you here. But I don't see any easy way to fix your problems.

--DD

[JP Noonan]

Sounds silly, but try changing the plugs. I remember a Champion rep that was telling us one day (trying to sell his new improved "truck" plugs display) about old carburated cars (that young guys like us wouldn't remember) having the problem you discribe. I don't remember if changing the heat range was neccesary, but try putting in new plugs. I recomend Bosch Platniums, about $2 each but are near impossible to foul. In my opinion don't throw your money away on Splitfires (Sh**fires).

Another thing, depending on how cold we are talking about here, is to use a crankcase heater. They sell ones that replace the dipstick and then plug into the wall.

[Bunky]

This is kinda out of left field, but, VW type I manifolds have a tube that connects to the headers and then run along the underside of the manifold, supplying heat. Similiar problems? Or maybe preheat the air, ...with some sort of attachment to the air cleaners from the heat exchangers? Am I way off?

[JP Noonan]

Thats sounds right, I think the tube is there to avoid "icing" the veturis (or something like that). Iceing happens at the thoats of carbs at high speed because of the "Venturi" effect, something like a ram jet. The compressing/decompressing of the air causes a vacuum, which in turn pulls the gas through the jet into the air stream. This also drops the air temp to the point of ice forming, even if the outside air temp is above 32 degrees. One of those pv=nrt formulas I slept through in class. Thats the way I understood it anyway. The 75-76 1.8L and 2.0L cars I've seen have EGR tubes off the exhaust system that go to the intake. Maybe you could use that. However I think the bettle system is seperate from the intake, that is it dosen't inject exhaust into the carb. In any case it wouldn't really help a cold start, until the exhaust has time to heat up.

Another system used on many water cooled cars is a "intake air preheater". It looks just like a heat exchanger with a 2"-3" dia tube that feeds into the air intake. Inline with the tube is a thermostaticaly controled vavle, when the engine warms up it shuts, and then only cold air is taken in. Again though this is only to help the engine come up to opperating temp faster, it dosen't do much to help a cold start.

One other thing is timing that is too advanced can make a car hard to start. If the timeing is O.K., and ALL else fails, Crane Cams makes a HI-6 ignition that retard timing on start up then at low RPM puts out multiple spark, and at high RPM puts out one big fat spark. Downside is it's $200 and may not cure your problem.

Yet another crazy idea, try dry gas. If the temp dropped suddenly and the local gas stations don't have the winter formula gas, there may be ice forming in the lines.

[Dave at Pelican Parts]

A few things:

The earliest 914s, with the "oil bath" air cleaner, had a provision for pumping heated air into the intake. Possibly a legacy from earlier carbeurated intake designs. But that won't help a cold start, as JP said.

Next, I disagree with JP's recommendation of Bosch Platinum plugs. Let me re-phrase that--I disagree with someone recommending the *cheaper* Bosch platinums; the really expensive ones are just fine if you want to pay that much money.

My mechanic has had lots of bad experience with the cheaper Pt plugs. I guess the quality control isn't all it should be, or something like that. He says that they tend to foul easier than plain ol' copper plugs, and that the speck of Pt sometimes slides right out of the plug center electrode to the outer electrode. No gap, no spark. It's happened to him a lot of times, so he recommends against them.

I do know that when my 1.8 would not start, one of the things he did to get it to start was replace the cheapo Bosch Platinums I had installed with Bosch Coppers. Started just fine after he got done with it.

--DD

[JP Noonan]

WOW! I didn't plan on causing such a rucus. My experience with Bosch platinums has been O.K. Meaning that I gap them, put them in, forget about them for 10,000 miles, replace them. I've always been one to try different tune up parts, I fiqure the law of avrages, one time I use Fram the next napa, the next OEM. However my experience was with BP's (to clearify I use the "pure" platniums, ceramic tip with plat wire core, not the platnium plated copper ones) in my 93 ford lightning and my friends 250hp nitrous shot 66 F-100 pro-steeter. The BP were the only plugs in the pro street not to foul out after a few 1/4 mile runs.

Is it at all possible that (I 'm going WAY out on a limb here) that the Bosch book is recomending the wrong plug for 914's (it would explain the multiple replies of problems)? Or maybe BP don't work well in an aircolled engine?

Anyway, without sugesting any one manufacturer, try putting in new plugs.