Cold starting problems

sicksteve

Active Member
I've experienced this twice in my '73 Riviera GS.


First let me mention my modifications:

*new ACCEL 71105e electronic billet distributor
*new ACCEL P/N 35366 "ultra high-performance" ign.module
*new ACCEL 300+ spark plug wires
*new AC Delco R45TSX plugs gapped @ 0.065"
*new Jacob's Ultra Coil (the original, big boxy, epoxy-filled one with a "variable magnetic core")
*new Optima Redtop battery
*new 2/0 gauge battery cables ("+" to the starter, "-" to engine ground) with other ground straps from the engine to the firewall and chassis, and from the "
"-" battery terminal and the body
*new POWERMASTER 9202 starter/solenoid
*a new dedicated ignition switch with 10 gauge wire fused to the battery to a hidden switch in the car to the "+" terminal on the coil, which also connects the ACCEL "+" power wire lead.

First of all, after I did this work, my Riv ran GREAT: silky-smooth idle; crisp, instant throttle response; no bogs or hesitations; increased HP, torque and mpg (from 8.9 to 15.1 mpg!!). Although I must add that when I first installed the ACCEL distributor, the engine wouldn't start because the distance from the magnetic pick-up to the reluctor had to be adjusted; it's supposed to be ~0.005" I drove it to Grand Forks, ND in colder weather for Thanksgiving and Christmas, and never had any problems with the car starting in very cold weather w/o any snow. It would immediately fire-up when I cranked the starter and flipped on my new ignition switch.

But when it was covered with snow and ice from sitting outside after Minneapolis' first snow storm, it would crank over, and sound like it was about to fire, but the engine would not run.

After many attempts, I thought it could be a fuel, spark, compression, ignition or battery problem.

So, I replaced the inline fuel filter, checked the fuel pump (it was pumping gas), tried another new jacob's Ultra Coil, fully trickle-charged the battery after I drained it from cranking it too many times for too long. I unscrewed the distributor's cap to see if anything looked amiss. Nothing looked apparently wrong.
The engine still would not start. I suspected the ignition module, because I had similar problems with a '70 Toronado electronic ignition system I added.

Later when it warmed up a bit a few days later in the early afternoon, the engine finally started and ran well.

Well, last night snow fell and covered the entire car.

Now, it won't start or run again. It seems to sound like it's just about to fire up, and then gives up.

What could be the problem? I know gas isn't as volatile in colder conditions. Usually gas is treated for different seasons due to the effect of ambient temperature on gas volatility. But I'm wondering if something in the ignition system could be susceptible to cold temperatures???

Does anyone have any suggestions?
 

sicksteve

Active Member
Yes, I think it does. I know my '76 riv's carb does. When I looked in my '73 Buick manual, it says it's a Rochester Quadrajet 4MV (I think that's model #; they vary with whatever car it is used in). The throttle plate over the primaries is clearly closed when the carb is cold. There's some kind of electric solenoid behind the fast idle cam. I guess its purpose is to increase the idle speed until the engine warms up (?). That also works.


So today, I tried starting it in the late afternoon. No problem--it started and ran very,very well--like it usually does, even with a discharged battery.

When I first encountered this problem, I thought it was fuel-related (possibilities: bad gas that isn't formulated for cold temperatures, the carb's choke, the fuel pump, an EGR valve stuck, something that is not allowing warm air to pass through the intake to warm up the carb). But this afternoon, it was still cold out, and it started without a problem.

When I had a point-type distributor, I never had this problem (but the car was never covered with snow because the '73 was purchased less than a year ago).

This problem only seems to happen when the hood is covered with snow. Both times, it seemed as if the engine was just about to start, but wouldn't.

Could the ignition module be susceptible to the cold? I had the same problems with my '76 Riv 455--which had --- when I put the same ACCEL module in its HEI (P/N 35367--whichc is the same "ultra high-performance" module as the #35366 module in my '73's Accel 71105 dist., except a smaller in size to fit the smaller 71105 dist.). The '76's carb always ran vey lean. In the CA desert, it used to be hard to first start after being in storage for a while, and would run rough until the engine warmed up. Now, this car is kept in a heated garage. After I put another ACCEL replacement module (a more stock-looking, "high-performance" one) and the same upgrades as in the '73 GS, the '76 then started and ran very well immediately--no rough running.

This problem really bothers me:clonk:
 
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sicksteve

Active Member
I looked in the '73 manual. The main possibilities are all choke-related. The choke appears to be operational, and functioning.

One weird thing I noticed is some accumulation in an intake indentation by the carb. The '73 service manual also listed a cracked/porous float bowl as another possible problem.

How do I check for a cracked float bowl?

The car is always outside in sub-zero MN weather (why did I ever move here from CA???). I can't work on the car more than a few minutes without my already frost-bitten hands going numb.

This is the third time this has occurred. It will start and run perfectly for a few days, and then, inexplicably, not start in the cold.

Any advice???? This is driving me crazy!!
 
You may be able to eliminate your spark/distrbutor concerns by putting a timing light on it the next time it is stubborn.
 

Santa Fe Red

New Member
Cold Starting Problems

'Steve,

I only mention this because you've done a ot of the obvious stuff AND you're new to Minnesota (where it is much colder than California). The fact is, cold weather slightly decreases the voltage available from a battery system and DRAMATICALLY decreases the amperage.

You might consider experimenting with one of those portable jump-start batteries that you can keep in the house overnight. If a warm portable battery starts your Riveriera on those cold mornings, you will know that your new ignition system is asking for more than your cold batery can provide.
 

sicksteve

Active Member
That thought ran through my mind, because even a Lexus i have parked outside with the same Optima battery, sometimes takes a bit longer to start.

You're right that the coldness does reduce the available amperage and voltage available

And because I have that big spark plug gap (o.o65"), it does require more voltage from the coil to arc the gap. I know it does seem large, but after trial-and error and using tips from Jacob's ignition secrets, I seemed to get the best performance out of it. Considering a stock GM HEI uses a 0.060" gap, and my ignition system is capable of producing a hotter spark, it isn't that big.

Dr. FrankenBuick, the stock Rochester Quadrajet 4MV carb does have a choke. Its thermostatic coil is in the intake manifold connected by a rod to the choke plate. The last time I looked at the carb, there was a small amount of gas around carb in the indentations of the intake. I tightened up the carb's 4 bolts to the intake.

Then I tried some squirting some starting fluid into the carb by myself, and tried to start the car. It still wouldn't start (it almost seemed like it was about to).

The starting fluid said, if using that wouldn't work, then the ignition system is likely responsible. That's just weird because the ignition system was working great, even in the cold, after adjusting the pick-up to reluctor air-gap.

I appreciate for all the suggestions. But i think that the carb may have to be rebuilt, especially since I noticed some gas that had leaked out of it.

Does anyone have a suggestion for a good carb rebuilder? I see that TA performance has a carb re-building service that is a bit expensive.Has anyone had any experience with them?
 

65specialconvert

Active Member
in that cold weather,the gas cant vaporize enough for the gap you have on the plugs to fire correctly.close your gap on the plugs :thumbsup: btw accel products arent the best anymore:D
 

sicksteve

Active Member
Thanks again for the advice, because you're all right

I really should try a different gap again, now that the season changed from when I last made all the adjustments.

65specialconvert: I think you're right, too. Even though I have gotten some great performance from some of the ACCEL products, others did have problems.

The most irritating one was when I dropped in the new-in-the-box ACCEL 71105e "billet" distributor, I racked my Brain for weeks trying to get it started After checking all possible problems (new starter afterthe old one wore-out, fuel pump, carb, compression, electrical system, wiring, etc.), I finally found that the problem was the aforementioned air gap between the reluctor and magnetic pick-up was not within manufacturer spec's. You would think that a new distributor's configuration would be set right from the factory.

And I did have more problems with ACCEL stuff, when I used their best 7.5 amp ignition module for my '76 455's HEI--same one that's in the 71105 distributor. After the same frustrations, and checking all these possibilities, the module tested bad. When I replaced it with a more stock ign module, it ran great. Like someones said, GM HEI's are as good as some aftermarket ignitions, unless you're a racer and need to operate over 5000rpms. Even the original HEI (with stock-spec 0.060" gapped plugs) in the '76--which I don't think was ever serviced, and showed signs of wear (pitting, corroded contacts in the dist.cap, carbon tracking)--worked pretty good by itself. I drove it across country, and never experienced any problems--except the same cold staring problem when I went through a snowstorm in Colorado . But I must say, that when I did finally replace all the HEI parts, it ran beautifully, much better than before. And to ACCEL's credit, they replaced a few parts I had problems with immediately, w/o any charges or even a receipt from the ebay retailer I bought them from.

I have an extra new MSD ready-to-run distributor for BUICK 400/430/455 engines, since i got a few 455's. Maybe that's better distributor.

But the point is that there must be some correlation with the same cold-starting problem they both exhibited..

Spark plugs can be an indicator of how an engine is operating. And in both Rivieras, the original ones were extremely clean--no carbon soot, deposits or oil. I suspect that the carb's were adjusted to have a very lean fuel/air mixture, which may contribute to these cold-staring difficulties.

That's why I'm thinking of having the '73's rebuilt to have a richer mixture.I think these carb's from the early smog period are a pain in the ____ to deal with.

With the '73, it's just bizarre that it used to always start in very cold weather immediately. I used to love driving this car all the time, and hate having to drive a Lexus

So it's either a fuel issue, or less likely, an ignition problem. But then, who knows...:confused:

Dealing with these cold starting difficulties, I feel like a dog chasing its tail.
 

sicksteve

Active Member
What about this description of a cold start problem with Quadrajets?

"Common issues with the Q-Jet are the primary vacuum break (aka, Choke Pulloff) will start to leak and will cause cold start to start, then stall, then restart ok symptoms. But overall is generally ok to drive."

Another comment was that Quadrajets tend to leak from the float bowl (which would explain the bit of fuel on the intake around the carb) from some orifice that can be closed with some epoxy.


And '73 manual mentions something about some air-bleeder valve filter

Also I found a comment about colder air being more dense (and having proportionally more O2), which would require a richer fuel mixture.
 

sicksteve

Active Member
Okay, help me out on this one:

I did appreciate the advice on the spark plug gap. So I did regap them to 0.050", and the engine still wouldn't run. And with the new ignition system and it's o.o65" gap, it started and ran great, even when the car was sitting out all night in very cold North Dakota.

Someone also said that if the float in the fuel bowl is not working right, the fuel pump will keep pumping fuel into the chamber.

On warmer days, the extra fuel would vaporize (and the engine would run), but on colder ones, it wouldn't and would flood the engine.

This would also explain the little bit of fuel on the intake around the carb. (In December I replaced the in-line fuel filter and wrapped the metal fuel line inlet's threads with Teflon tape; so I don't think it should be leaking from there).

The choke plate appears to be working. It is fully closed on a cold morning. and the fuel pump is working, too. The ignition system was working in very cold weather.

I tried starter fluid, and the engine almost started. Then my optima battery has lost enough power that it needs to be re-charged from all my attempts to start it.

I'm thinking of having the carb re-built, but am afraid of it not working like it used to when it was running perfect. On others cars, whenever I have torn apart the carb, and re-assembled it, it never seems to run the same.

So, where should I go from here?
 

sicksteve

Active Member
Thanks for the suggestions. I do appreciate everyone's input. I should check the spark. Someone said there's a cheap spark testing tool.

But, since I've only had this car for a little over six months, I'm not as familiar with it as i am with my '63 Riviera I've had for 24 years. When you have a car that long, and replace or rebuild almost every part, you begin to know what areas that may need attention or may cause a problem.

With this '73, even though I've done quite a bit of work on it, I've never touched the carb--except to adjust the fast idle rpm setting, and replace some vacuum caps and fuel lines. Since the ignition system was completely replaced (I even wired-in a new hidden ignition switch, with 10 gauge wire fused at the battery, which powers the distributor and "+" side of the coil) and working better than any electronic ignition system I've had, I doubt that the ignition system is at fault.

The gap issue: If it were my large plug gap that's causing my problems, why wouldn't i have experienced difficulties staring when it was in even colder weather? On the contrary, it ran better than I had ever expected.

It is possible the ignition module fried. It has ACCEL's best 7.5 or 8 amp version--which would dissipate a lot of heat). It is open, unlike other modules which are covered in epoxy. I used the same one in my '76's HEI, and it was bad from the beginning. When I replaced that, and a ground strap in the in-cap coil, it started right up--but that car was in a heated garage.

And I've had the same cold weather starting problem in my '76 when I drove it from SoCal to MN. When i got caught in a snow storm in the Rockies, it exhibited ALL the same symptoms as the '73. At that time, it had the stock HEI. The previous owner had replaced this choke linkage. The '76 was only used as his Palm Springs car. So, using this car as a comparison, I'd have to say the carb was responsible.The '73 was stored all winter in a heated garage by the previous owner. Now it's kept outside in the cold.

But the carb: I've been reading everything the '73 manual says, and comparing what it has to say to what my carb looks like. The choke plate and choke operate. The previous owner removed and plugged all the vacuum ports, except to the distributor's vacuum advance (with no NO TCS in between, either), the PCV inlet and the power brake diaphragm.

the main possibilities the '73 manual states for cold-weather starting:

1. driver's habits
2. check choke valve, linkage--binding, stuck or gummed up

other less likely possibilities:

*choke rod adjustment--no, it's fine
*check vacuum break adjustments--appears to be working. I can't tell unless the car is running.
*check choke coil rod adjustment--okay
*check choke unloader adjustment--if I could get the engine running, I could check this, because the vacuum is supplied by a running carb's vacuum to the two vacuum diaphragms; otherwise I need an external vacuum source. There's a primary vacuum diaphragm which will open the choke a bit so that the engine runs w/o loading or stalling. The choke plate should open a bit more by the secondary vacuum diaphragm after the engine is running to prevent loading and reduce emissions. The secondary diaphragm's action is delayed to prevent stalling. It also has a clean air purge beneath a rubber-covered filter to bleed the system of fuel or dirt, which may enter the check bleed vale and disrupt its operation
*leaking or cracked fuel bowl or mis-adjusted float pontoon--I'm not sure.
*throttle body to float bowl screws loose--possible
*accelerator pump inoperative--I don't think so; it was working before. And this seems very unlikely
*primary metering rods wrong, bent or mis-adjusted--don't know.

Unless, i tear apart the carb, I won't know about some of these. I did use starer fluid, which was not successful in getting it to run.

Last night, i tried to start is again, and it almost did when I floored the accelerator to clear a flooded engine. But, the battery has lost most of its reserves with all my starting attempts. It's remarkable this battery has held a charge for as long as it did. Even after a lot of cranking, repeatedly, and losing reserve current, it still retained juice days later; so it's on trickle charge now.

I don't want to needlessly have this carb rebuilt because it was running well. but what do i have to lose (except money...) at this point since the engine won't start?

Again, I'm getting frustrated for something which should be an easy fix. ACCEL sent me another module free--I can try that. The inside of the carb remains a mystery.

Any other suggestions?
 
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