1978 New Yorker, so many questions, just 1 for now

[rowjelio]

I just bought a 1978 Chrysler New Yorker 400ci, LOVE the car, but after driving around a while, the car warms up, then it struggles to start. Cranks great. After about 5 seconds of cranking it finally starts. It's got lean burn delete conversion from the factory.

Is this gonna be something easy like the ignition coil or something? Any quick fixes to try first ? Starts like a match the first few times before that starts happening.

Don't know much about this car, Any input is appreciated.

 

[CBODY67]

Does the driver's door have a "Catalyst" sticker on it? Is this a Canadian-spec car? How do you know it is a "factory" Lean Burn delete car? Just curious.

The longer crank time when starting after a "heat soak" is somewhat normal, but a bit frustrating. You can ensure the tune-up items are up to snuff. As to spark plug condition and gaps, base timing is correct (which is why I am curious about the "factory" LB delete).

This is NOT like a modern EFI car, you need to add about 1/3 throttle when starting, almost any time. Then release it to hot base idle after it starts and before you put it in gear. Learning what the car "likes" and "acts best with" is ONE part of the character of vintage vehicles, no matter the brand.

Also, in addition, the first start of the day, put the gear selector in "N" from "P". This lets the torque converter fill faster so that after it starts, going into "R" is more normal. Not doing this leads to the car being lethargic to move when put into gear. ONLY the first start of the day.

Just some thoughts,
CBODY67

 

[rowjelio]

Does the driver's door have a "Catalyst" sticker on it? Is this a Canadian-spec car? How do you know it is a "factory" Lean Burn delete car? Just curious.

The longer crank time when starting after a "heat soak" is somewhat normal, but a bit frustrating. You can ensure the tune-up items are up to snuff. As to spark plug condition and gaps, base timing is correct (which is why I am curious about the "factory" LB delete).

This is NOT like a modern EFI car, you need to add about 1/3 throttle when starting, almost any time. Then release it to hot base idle after it starts and before you put it in gear. Learning what the car "likes" and "acts best with" is ONE part of the character of vintage vehicles, no matter the brand.

Also, in addition, the first start of the day, put the gear selector in "N" from "P". This lets the torque converter fill faster so that after it starts, going into "R" is more normal. Not doing this leads to the car being lethargic to move when put into gear. ONLY the first start of the day.

Just some thoughts,
CBODY67

Thanks so much for that, I meant that it came with lean burn, but was taken back to the dealer and had the leak burn conversion from the dealer. Pretty sure. I'll post some pics once we get some sunny days. I have a whole list of things I need to fix on this thing but it's mostly there, thanks so much for your advice it's been a tremendous help!

 

[CBODY67]

In earlier times, it was popular to install the Mopar Performance electronic ignition conversion kit to vehicles which either had ignition points or as a part of the LB removal situation. Easy, cost effective, and all factory items (distributors, harnesses, etc.). Then whatever needed to be done on the carburetor situation, as that's where most of the "lean burn" calibrations (as I understand it) were. The "computer" modulated the timing to greater levels than an "analog" distributor could, but "the kit" deactivated and removed that part of things. IF they used that kit, it basically makes the bulk of the tune-up specs on the labels under the hood meaningless, as to basic timing and idle speed. Back to more of a "what works" situation. Spark plug heat ranges and gaps would not change, though. Hot base idle speed could probably go as low as 625rpm or so, too.

So, thanks for those clarifications,
CBODY67

 

[halifaxhops]

Sounds like the typical ECU or pickup coil failing when warm then cools off and starts.

 

[commando1]

It's got lean burn delete conversion from the factory.

Impossible.
More likely dealer installed.

On the hot start problem.
You need a new HO battery. AMHIK.

 

[rowjelio]

Impossible.
More likely dealer installed.

On the hot start problem.
You need a new HO battery. AMHIK.

you're right i meant to say dealer not factory, sorry, i was just trying to make the point that there is no lean burn. what's the HO battery?

 

[GOLDMYN]

Are you giving it some gas when you crank, most instruction manual says to give it some gas when hot, the gas that was in there has evaporated

 

[rowjelio]

Are you giving it some gas when you crank, most instruction manual says to give it some gas when hot, the gas that was in there has evaporated

my chevy needs to be pumped. should i pump or hold it down?

 

[HWYCRZR]

Press and hold the gas pedal about 1/3 of the way down and then crank. If your carburetor is good, pumping will just flood it.

 

[commando1]

you're right i meant to say dealer not factory, sorry, i was just trying to make the point that there is no lean burn. what's the HO battery?

I meant a strong decent battery with high crank amperage

Why is everybody telling him to flood the carburetor?

 

[Mr C]

I am curious what carb a Dealership put on your car as part of their LB deletion. Is it still a TQ?

 

[75LandYacht]

I am curious what carb a Dealership put on your car as part of their LB deletion. Is it still a TQ?

I agree with Mr. C, if it still has the thermoquad carb.. get rid of it for a new Edelbrock or carb of choice.. The Thermo quad is not for a newbie or tinkerer. The newer carbs are easier to manage and run better in my opinion.

 

[commando1]

I agree with Mr. C, if it still has the thermoquad carb.. get rid of it for a new Edelbrock or carb of choice.. The Thermo quad is not for a newbie or tinkerer. The newer carbs are easier to manage and run better in my opinion.

I'm tired of carrying that flag. You are now the guardian of the cause.
I'd like to see one thread about permanently trashing that POS without one whackadoo spewing it's virtues. That whackadoo is on LSD.

 

[Big_John]

After about 5 seconds of cranking it finally starts.

he longer crank time when starting after a "heat soak" is somewhat normal, but a bit frustrating.

Yep, 5 seconds of cranking time on a hot start isn't optimum, but we're not driving new cars that can restart at every traffic light. I think there's a lot of guys that would be tickled if their car did a hot restart with only 5 seconds of cranking.

You can ensure the tune-up items are up to snuff. As to spark plug condition and gaps, base timing is correct

^This^ So many times I see these threads with all sorts of suggestions about changing this or swapping that and nobody stops to look at the basics. For example, if the car needs plugs, there's not much that is going to help until the plugs get changed.

 

[rowjelio]

I agree with Mr. C, if it still has the thermoquad carb.. get rid of it for a new Edelbrock or carb of choice.. The Thermo quad is not for a newbie or tinkerer. The newer carbs are easier to manage and run better in my opinion.

I guess it has a quadrajet in there. I replaced a valve cover last weekend and was surprised to see!

Okay I'll replace some basic tune up stuff and see if it helps, thanks guys

 

[CBODY67]

A QJet? Look for the 8-digit number stamped into it somewhere. Then Google that number to see what it might fit.

Just curious,
CBODY67

 

[zdgimbus]

Everyone hates the thermoquads and quadrojets, but I love them and it's all I run I rebuilt the thermoquad on my 78 400 did lean burn delete and it works great (I got a how to rebuild manual) and was able to figure it out. Any how my 78 newport was running warm and basically doing the same thing as your car long crank hot start. I ended up replacing the factory rad with a aftermarket aluminum rad and also put a 180 degree thermostat in it now it runs cooler and no more long hot crank lol, you could try putting a 180 t stat in so it runs a little cooler that may help you

 

[Tsagoth]

Mine has always been like that. Cold, it starts right away, if it's been driven in the last few days. If it's been parked more than a week, it won't start unless you pour a few ounces of gas down the carb throat, ether won't work. When it's hot, if you shut the engine off and restart it within 10 minutes (like after pumping gas say) it will instantly restart. After that though, it cranks for perhaps twenty seconds before it lights off. You also usually have to hold the accelerator pedal down just a crack. It will start if you don't hold the pedal down that tiny bit, it just takes longer. What's more annoying though is after the car sits for, oh, 45 minutes, it won't start unless you pop the hood and take off the air cleaner lid and let it air out for five minutes. Or hit it with a small dose of quick start. My hypothesis is that when it sits that long, it's vapor locked. Now with the constant 90F+ temps everyday, once it's hot and you shut it off, it won't start at all, unless you hit it with quick start. Basically it's vapor locking as soon as you turn it off. Waiting for cooler temps, because it's really not drivable in this hot weather like this.

What I mean at the top there when I say ether won't work is that it will fire on the ether, but after running for ten seconds, it quits. You can dump a whole can of ether in and that's all it will do, is run for ten seconds at a time with each ether dose. Pour five ounces of gasoline into the carb and it will start and run all day. My guess is that the float valve sticks and the short runtime with ether isn't enough to unstick it, but the gasoline makes it run just a little longer and the extra vibration is enough to unstick it, but who knows really.

The lean burn was replaced with an regular electronic ignition before I bought the car.

 

[CBODY67]

I do NOT dislike TQuads or Qjets. I like the principle of the smaller venturis for better fuel atomization in cruise situations with the larger secondaries to make up for that at WOT. Both carbs are very flexible as to tuning, being a "metering rod" carburetor. Look at how many different engines the QJet was used on, OEM! BUT what I dislike about them is that you have to remove the accel pump pivot roll pin to take the top off of the carb. Not user-friendly. With very easy driving, without changes in manifold vacuum, the power piston CAN stick in the "full-down" position, which means that all acceleration ends as the accel pump shot is all used up, UNTIL you dump in some good carb cleaner in the tank and drive it with lots of throttle ons and offs, to vary the vac level to get the power piston unstuck Been there, done that!

So I like the basic design of the TQuad much better. It must be good or Holley would not have used it for the basis of their Street Demon line of carbs, with FEW changes. I became a bit sour on them when the CS-9801 TQuad did not offer any real improvement in mpg over the stock AFB on my '67 Chrysler 383 4bbl. Zilch! Throttle response did not improve, either. This was with the allegedly matched combination of that carb and a Torker 383 intake. It did have more WOT power once I started using the thick OEM-style base gasket, though. The 9801 had Chrysler linkage on it as the normal 9800 had GM linkage on it. I did like the full-electric choke, though. The TQuad has a huge float bowl capacity compared to the QJet, too!

In my years of chasing the hot re-start time issue, I ensured that all of the tune-up specs were where they needed to be on the '66 Newport 383 2bbl. Never did find anything wrong, back then. So the issue became WHAT THROTTLE/Accel pedal position to use to get the engine started as quickly as it could! Generally, the Chry-recommended 1/3 throttle position worked best. This was back in the middle 1970s when premium gas was abt 100 Research Octane, too! Seems like I helped it some with NGK V-Power spark plugs (due to their more exposed flame kernel). It's all in finding out "what the equipment likes" rather than doing differently!

Before putting fuel into the primary throttle bores, check to see if the accel pump shot is operating. Cold or hot. If not pump shot happens, that's a clue there is no fuel in the fuel bowl (it feeds from the lowest part of the float bowl). If there is pump shot, no need for the additional fuel. If no pump shot, add fuel into the bowl vent tubes rather than the throttle bores. When then means you can use the accel pump as designed.

After I determined the TQuad would not provide me the benefits it was supposed to, I removed it and found a used 4160 Holley from a '69 383 4bbl. Performance and drivability were danged close to the same. BTAIM

Just my experiences,
CBODY67