Difficult to start after engine is hot.

[kevinkpk]

I don't believe egr valves were around in 1972, seems too early, but I could be wrong. My 70 has California emmissions on it, thats why I was asking.
I have a friend with a 79 Ranchero GT he has redone, and afterwards is having the same problem with it not starting hot, unless he hits it with starting fluid, we'll figure it out yet. I bet after tommorrow someone will respond to your post with something not already brought up.

[J-(Chicago)]

I took some pics of my 72 delta's motor.
There is no EGR valve so you don't have to worry about that one.

Thermac, & hot air choke tube


It may be listed under Thermostatic in your manual.

[Olds64]

2)No Fuel in Carburetor?

You continually mention that it seems like the fuel bowl runs out of fuel. Quadrajets were notorious for having leaky jets. When rebuilding the carburetor assemble the jets intothe fuel bowl. Then turn the fuel bowl upside down and you will find two plugs underneath the jets. These are plugs put into the fuel bowl under the jets because during the original machining process they drilled straight through the fuel bowl. Coat the plugs with a liberal helping of clear nail polish. The nail polish is fuel resistant and will seal the plugs and prevent the jets from allowing the fuel bowl to leak. The leaky jets usually allow the fuel bowl to drain after sitting overnight, but this could be part of your problem.

Defective Fuel Pump?

Take the fuel line off of the front of the carburetor. REmove the coil wire from the distributor. Have a buddy crank the engine while you hold the fuel line in an empty coffee can. The fuel should spew out of the fuel line with good flow. You should have a small pool of fuel in the bottom of the coffee can after a few moments of cranking. I know this is pretty vauge but it is a good way to test your fuel pump for flow.

Check float needle for sticking in seat or binding float.

Rebuild the carburetor.

Just thinking following the service manual would be a logical way of going about troubleshooting. Hope it helps.

[kevinkpk]

I can't envison anything after 1970 having the old coil spring choke control that just screwed to the manifold, but I'd think it was as one of the images that J Chicago posted showing the heat tube to carb.
I wonder if (all things now point to carburetor in my thinking) it is vaccum lock occuring in the throttle body of the carb, hence rebuilding. Been a LONG time since I've been inside a quadrajet.
One thing to check is with the air cleaner off, try to wiggle the carb left to right, if it moves, there could be your problem. If it dosen't it still could be a gasket leaking air into the carb, past the venturi, either way, it's I'd suggest carb overhaul. I believe the quadra jet has the hold together screw head from the bottom (manifold side).

[J-(Chicago)]

Yes kevin, he should have the same setup as my motor.
They are both 1972 models
Mine is the 455, and his the 350.

[Modern Motoring]

[quote=kevinkpk;19914I have a friend with a 79 Ranchero GT he has redone, and afterwards is having the same problem with it not starting hot, unless he hits it with starting fluid, ......[/QUOTE]


I had a 53 Lincoln that did the same thing. I had the carb rebuilt, new coil, complete tune up( wire plugs et all ), installed a new electric fuel pump, new battery... I figured the car hated me, so I sold it and bought the 63 Olds 'vert!

[New'n72]

Thanks for all the ideas, guys. J-, Thanks for the pics. I actually knew what the Thermac and shoke tube were. I had been there before. Mine is as yours is. The tubes and hoses are the same and the tube to the valve cover is the same.

A couple questions and a few reiterations in responce to everyone's comments:

The carb. has not been rebuilt. I believe I stated that previously? BUT....if it was a carburator problem wouldn't it also show up while driving?

Every once in a while, I get on it just to hear her roar. Never a cough or sputter. She goes like she's just been waiting for me to give her more fuel.

I don't smell gas like I would expect if there was a flooding or a leak situation.

I think a gasket leaking air into the carb. is a possibility because the car sat for years without being driven and I know gaskets dry out. This may also explain why temperature seems to affect the symptoms? Deminsions change from hot to cold and visa versa.

The fuel pump, fuel line and filter are all new this past summer.

Based on my drive, Thursday, and the change in outside temperature I think we may have to wait until it warms up again to get the symptoms back. I will go for a drive again this week end and see how things act. Thursday, I could not recreate the symptoms, but it was 35 degrees outside and this past summer it was a lot hotter when this happened.

We'll see................

The Service Manual says its a fuel pump problem or a stuck float needle. However, the trroubleshooting chart in the Service Manual does not specifically deal with "Hot Starts". It referes to failure to Hot Start as a "starting proceedure problem" and if that is not the cause then look to Cold Starting problems for a solution. Not really very definitive.

One thing I want to try when this happens again is to take off the air cleaner cover.
I did that once last summer to watch the choke and it may have actually helped the situation. I didn't have to crank very much with that cover off. The choke, by the way, slowly closed as the engine cooled down, as it should.

[J-(Chicago)]

Exactly.
I was worried about the thermacs functioning properly on the air cleaner housings because the bigger one is vacuum operated by that vacuum line, and may not be opening to let enough air in.

If you took the line off of it and put a vacuum pump on the nub... the flue should open and close as you pump it up and release the vacuum. If the car starts much easier with the cover off, it may not be pulling enough air inside.

The little one in the back/bottom of the air cleaner is for cold starts, and moves up and down by vacuum as well.

You can check your base gasket for leaks by spraying a little bit of starting fluid through those little red plastic WD40/brakekleen can nozzle tubes.
spray a little bit on the gasket mating area while it idles, and if the motor starts racing up, it is pulling the ether into gaps.

[New'n72]

I did a little driving this week end and I could not get the symptoms that I expereinced last summer.

I pretty much retraced my steps from last summer as for as distances and duration of waiting with engine off.

She started on the first crank every time.

I guess I will have to wait until it warms up around here before I can tell if the problem still exists.

Thanks again for all the help. Believe it or not I am acutally learning a few things from all your comments and suggestions. I will update this thread if/when the symptoms return.

[Dynamite]

Not to be smart here guys, but guessing at a problem only confuses things and makes it more difficult. As frustrating as trouble shooting charts are, they systematicly eliminate and narrow down possable causes.
My suggestions to narrow it down.
Heat the engine up to the conditions where you know it will not start.
Pull aone spark plug lead off and either use a tester, or a grounded good plug to see if you have spark. If there is no spark, the problem is ignition.
Dump a small amount of gas down the carb. If it starts, the problem is lack of fuel.
Let us know which way it turns out, so we can go from there.

[Lady72nRob71]

New'n72,

Did you ever get this resolved?? I found this thread rather late...
Lady (my '72) has your exact same problem. In cold weather it is better, in hot it is worse.
My suggestions that I will undertake when it gets warmer out:

1-replace fuel filter (I heard some of them may have a check valve in them to keep fuel from backflowing to the tank)

2-Hook up the TCS system as it controls the spark advance. Previous owners disconnected it and is causing a variaety of problems.

3-Change the coil. It is not too expensive, mine is original, and I had experienced heat issues with coils before. the worst that could happen is that I end up with a spare.

4-Add the missing heat shield to the starter, as my car will crank slowly when very hot. It helps hold the starter on, too!

Hopefully we can find a cure for this.

[Lady72nRob71]

Oh, forgot to mention that lady had just been super-tuned up by a mechanic before I got her last year (new plug, points, cap, rotor, etc.)
A carb rebuild may need to happen soon, as I do not know the history.)

[Ndn_GivR]

I had that problem with my 1987 Cutlass, thought it was the choke and timing, put a new battery in er, problem solved. Freakin wierd.
Thought it was the timing cause when it it did start i could smell exhaust fumes, real stank.

[New'n72]

Lady72nRob71 - I have tried all that you mentioned. I think most of the information on what I have changed out is in this thread but this is getting kind'a long so you may have to back track quite a bit to find it.

NEW: points, plugs, plug wires, condenser, distributor cap, coil, fuel pump, gas line from fuel pump to carberator (stainless steel), fuel filter, battery, exhaust system ( changed from single to dual, plugged cross over).
Starter cranks fast and hard...not a starter problem.

Car runs fine on the open road. Lots of get up and go. No coughs or sputters.

I have not driven this car much over the winter. The few times that I did drive it, it started fine in all conditions.

I can appreciate the comments of the poster that said that "guessing at a fix has the tendency to confuse the issue", but I want to assure you all that I have approached this systimatically and I did use the OEM shop manual and its troubleshooting charts, but it did not fix anything.

My gas line does not have much of an arch to it, as I remember. Fairly flat accross the front of the engine until it drops down to the fuel pump. I did have a rubber hose I used as a stop gap to get it running initially. I destroyed the original fuel line, when I tried to remove it, because it was froze to the filter canister at the carburator. As I recall that rubber hose did have an arch to it and I had the same problem I still have now.

I'll see how it works when it gets warmer around here. That souldn't be too long now. Last thing I did was put a new coil on it.

[Lady72nRob71]

Dang... Sound like I may have the same hard time at this problem with my car later, as it seems to have your exact problem.

Only thing I can still think of is fuel drainback from the carb, as I ~think~ the inlet is at the bottom of the float bowl and not all fuel filters have a "check valve" device in them.
I heard talk about this on the G-body list a while back.

Maybe a definite fix will show up pretty soon...

[New'n72]

Lady72nRob71 - How many miles on your Cutlass? Mine has 112K. The engine has never been opened up and the carb. has never been rebuilt.

Just wondered how this compares to yours and if this might suggest something, based on possible differences?

[Ndn_GivR]

Mines a 87 with a 3.8, 149,000 k, carb was rebuilt 3 years ogo. So says the previous owner. But, i`m going to schedule her in for a top engine cleaning at a gm garage in the spring see if that helps. Or just live with it till i find a Rocket 350.

[Lady72nRob71]

New'n72,

Lady has (I think) 150K on her. The speedo says 50K and the previous owner was unsure, too. Since she is so old, she is true mileage exempt in TX. Engine and trans run like 50K and body condition supports that, too.
The interior and door mechanics wear indicates more like 150K, so that is what i am guessing.
I have a good paper trail from the previous 2 owners and I heard she had been sitting for 10 years from about 96-06.
Before she was sold to the previous owner, the guy had a 1700.00 'refreshening' done, including gaskets, oil pump, timing chain and gears, and tons more.
Carb has been monkied with at one time as the little cover on its back side (over the temperature compensator (?)) is missing and a bunch of screws were backing out.
Coil looks original so it is gotta be replaced. Vacuum lines are all misrouted, so I need to fix that, too.

[New'n72]

Update on this porblem:

Last Fall I replaced the coil on urging from one of my automotive knowledgable coharts at the office. I didn't drive it much after that because the weather started getting cold and nasty.

I start it up periodically over the winter and early this Spring I went out to start it up and it barely turned over. Sounded like a dead battery, although I was at a loss as to how that could have happened.

I also thought that maybe the starter was giving me a problem since the bendix occasionally fails to engage when I start it up, so I asked the local mechanic's joint to get a starter for me. The old guy at this place said he bet on the battery and asked me to bring the battery in and he would put it on a charger and test it. It tested bad.

I bought a new battery. 800 CCA. Once I had the car started I took it back to the mechanic and asked him to check out the electrical. He found that the alternator/regulator was over charging the battery.

So..at this point I had a new coil, new battery, and new regulator.

As the outside temp. warmed up I eventually got out and drove for a few miles. Then I took it to work one day. Never had any real problems but the last time I had it out I smelled gas. When I got home I found dampness around the base of the carb.

It appears that the fuel filter connection had loosened up a bit.

I have driven it a couple times since that and I have not had to crank and crank like I did last Spring, after it warmed up to operating temperature and then sat for a while.

I'm thinking that my starting problem was a combination of these things: battery, regulator, and possibly coil?

I learned quite a bit while working through this problem and I appreciate all the help that was offered. Hopefully the difficulty "starting when hot" problem is gone.

[Lady72nRob71]

Newn72,

Interesting you say this, as Lady's problem has really diminished after I cured the overheating problem. No more hot flashes, hehe...
She will not start ~sometimes~ when hot on just a burst of the key, but I do not have to crank a lot like I did before before.
I still want to change the coil to see what happens. I will switch to electronic ignition then also.

Also I found that my battery cables are not original and are only 6 gauge. The originals should be 4 gauge and would allow more current to and fro the starter.

Things are getting better at least!

[New'n72]

I am seriously considering electronic ignition also. Having had this car since it was new I kind'a wanted to keep things original, but with all that I have done so far, the EI is staring to look pretty good.

[Lady72nRob71]

I know how you feel about originality, as I feel the same.
However several Olds guys have used this one module
www.breakerless-se.com
and they were happy with it. Completely invisible. Year One sells it also.

At 150 bucks it on my backburner but the idea of no points to need adjusting or replacing sounds good, especially for when Lady takes me on some serious road trips later (thousands of miles at a time)...
I am willing to give it a try.

[Oldsguy]

Rob, I think that product would be better than the optically triggered ones. If the lamp ever fails you are in deep doo doo. The one you show is all magnets baby!!!

[Lady72nRob71]

Originally Posted by Oldsguy

Rob, I think that product would be better than the optically triggered ones. If the lamp ever fails you are in deep doo doo. The one you show is all magnets baby!!!

Dan you are very correct about the lamp (LED) failing. It can happen more often than one would expect under the harsh conditions it is faced with.

The optical trigger used in the high-end Delco stereos of the mid 80's had that problem with the tape deck. The light output from the IR LED gets dimmer and the reflector wheel gets dirty and the finish tarnishes. The tape deck would think the tape is jammed.

Hall-effect is the best way to go. My 78 Ford has that type setup from the factory and NEVER had a problem after 150K+! (Knocking on wood...)

I will try it later and report the findings...