Cranking Problem '68 Suggestions Greatly Appreciated

[jerthemost]

I have a 68 mustang with 289 engine. The block numbers actually indicate it’s a 302. 2 years ago I put an edelbrock 500 cfm 4v on it with edel performer manifold. Last year I put edel 321/347 performance package on it. After that I did have some cranking problems when the weather was hot. I am in Houston and we had a very hot summer last year. Edel sent me a heat soak gasket which helped a lot on the cranking.

When the car is cold, sits overnight I push pedal to the floor and back up twice to set the choke and it cranked perfectly on first turn of starter but after the car ran a few miles and heated up it was hard to start if I turned it off for a few minutes. The gasket did help that and then the weather got cooler and I had no problems all winter.
Now that summer is here I am back to the same problem but with a new twist that just happened 2 days ago. Now even when the car has sat all night it does not want to crank where just a few days ago I could set the choke with the pedal and it would fire right up. And each time it seems to be getting worse. It acts like it’s not getting gas. I am about ready to sell it if anyone is interested. My wife almost got stranded this morning and she is not happy. Seriously we love this car but this problem has to get solved or me or the car has to go. All suggestions would be greatly appreciated.
I do have the edel fuel strainer on it, I forget the number but is about 2 inches long and blue. That is my filter.

 

[Falcon79]

You might want to try trouble shooting the fuel issue by replacing the fuel pump and fuel filter. Since it doesn't matter whether it is hot or cold at this point, I doubt that ever had anything to do with it.

 

[horseballz]

When you say "cranking problems" do you mean that the engine cranks/turns hard/slowly/barely, OR just cranks and cranks at normal speed but doesn't start/fire up? "Cranking" is generally referring to the process of the engine turning/spinning by the starter until the engine "catches/starts/fires" and begins to run on it's own. Just making sure we are all on the same page, terminology wise, to have good/correct communication. Slow/hard cranking, when hot, can be a whole different set of problems than cranking normally but just not starting when hot. Just a curiosity, does your car still have a distributor with breaker points in it?
Gene

 

[jerthemost]

When you say "cranking problems" do you mean that the engine cranks hard/slowly/barely or just cranks and cranks at normal speed but doesn't start/fire up?
Gene

starter turn over most times normal but sometimes slugishly like low voltage but usually normal but does not fire. After i posted the original message my wife called me and said car would not start. I told her to remove air filter and hold pedal to floor a minute in case was flooded. She did and after 3 tries starter turned over a few times and started. This carb is only 2 years old and actually has about 14 months at most on it.

I checked battery voltage when she got home with car off and was 12.75 volts. I will remove the edel strainer tomorrow and check it. That is actually a strainer not a filter. Maybe i need a filter.

It is just strange that the not wanting to start at all just occured 2 days ago.

 

[jerthemost]

Forgot to mention i have Pertronics ignitor 2 with flame thrower 50kv coil and full 12 vdc ignition not resistor wire. My spark tester says i have good spark so i assume has to be gas.

 

[rbohm]

start by checking the float level setting. it sounds like it might be a bit high. second it also sounds like you have the beginnings of a starter issue, which happened by coincidence. if the float level is set properly, then likely you have a fuel boil issue and you need some sort of heat dam between the intake and the carb. one i suggest is this one from summit racing;

http://www.summitracing.com/parts/MRG-3710/

 

[woodsnake]

Also, you should go back and check the connections to the starter itself, make sure everything is still tight, and has a good clean connection on both ends...I have had similar hard start/hot start issues, mine have always been more electrical than fuel...

 

[horse sence]

i recently had what sounds like the same prob on a 73 mach, changed the starter
that cured the turning over brob but it turned out to be the accelerator pump
that wouldnt let it start up, it was hard and wouldnt pump, is it a holley?

 

[jerthemost]

The carb is 500 cfm edelbrock performer on edel intake. I have a heat soak gasket between carb and intake. About 3/8" thick from edelbrock. I can see where sluggish turning of the starter could be a bad starter or lose wiring but when starter is turniing over strong and stll does not crank i would have to assume it is not a starter problem.

Can someone explain the actual starting sequence in detail as far as gas is concerned? It would appear to me that the starter would have to turn over several times for the fuel pump to push gas up to the carb yet when mine is right and cold it use to start on the first turn or 2. Doesn't the gas drain back down when the car is turned off?

 

[DailyDriver_68]

I was having the same issues with my new Edlebrock 500 cfm carb about 6 years ago. I got a wood carb spacer from summit and i rerouted my fuel line (from the pump to carb) away from anything hot. I haven't had any problems since.


As for the starting sequence you mentioned, normally there is fuel in the carb bowls that will allow the engine to start upon initial cranking. However, if the fuel boils out of the carb, the engine will crank until enough fuel is pumped into the carb for the engine to start. Same thing happens if the car sits for a long time between starts and the fuel evaporates out of the bowls.

 

[jerthemost]

I was having the same issues with my new Edlebrock 500 cfm carb about 6 years ago. I got a wood carb spacer from summit and i rerouted my fuel line (from the pump to carb) away from anything hot. I haven't had any problems since.


As for the starting sequence you mentioned, normally there is fuel in the carb bowls that will allow the engine to start upon initial cranking. However, if the fuel boils out of the carb, the engine will crank until enough fuel is pumped into the carb for the engine to start. Same thing happens if the car sits for a long time between starts and the fuel evaporates out of the bowls.

The spacer i have is some type of synthetic like plastic but not really hard, about 3/8" thick. That should be as good as wood wouldn't you think? As for the fuel line it is rubber and is routed across the front part of the engine and does touch the engine for most of it's length so maybe i should try to reroute so is not touching engine. I would say the hard start when hot is because gas is boiling out of bowl or vapor locking in the gas line. Just have to try something until i find a fix.

This morning i did a cold start. I set the choke with accelerator pedal then removed air filter cover to verify choke and choke was right. I then hit the key without touching pedal and with cover off and after about 3 turns it fired right up just like it should. Really strange.

 

[horseballz]

jerthemost,
Rubber hose from the fuel pump to the carb could definitely be a contributing factor, compounded by contact with the hot engine. Go to the parts store and get a length of 5/16" or 3/8" steel brake line with the proper fitting on the end to fit your fuel pump outlet and bend it using pulleys or other large diameter round items to get the bends without kinking. Make it so that it touches nothing and ends up near and pointing to your carb inlet and put a clear inline filter, just before the carb. A couple inches of rubber here to plumb in the filter should be no problem. A few conditions could be happening when you turn the car of and try to restart depending on the scenario of temps and how soon after turning off you try to restart:
1>Very hot day, drive for awhile and park for 5-20 minutes. Engine temps can cause the fuel in the carb float bowls to boil out into the intake manifold, causing a flooding situation. Will likely start by holding throttle wide open while cranking.
2>As you get closer to or cross the 20 minute mark the bowls may be dry/empty, but raw gas is still in the intake manifold, so once you get the engine to catch by the standard "holding your foot to the floor" for a flooded condition, there is no fuel in the carb to keep it running. Now you have a "no fuel" situation which may get compounded by vapor lock, which causes you to crank and crank until the fuel bowls fill up. If your battery is even the least bit weak, you're screwed.
3>Hot day, after driving a while, you park the car overnight and all fuel boils out and the heat/time evaporates the gas from the carb bowls and intake manifold so you have no fuel in the carb to start the car the next cool morning.
4>Drive car for a while and park it in the cooler evening hours and even though a little fuel may boil out into the intake manifold, not enough boils to empty the float bowls, so all seems well in the morning.

Today's crappy fuel blends seem to be more susceptible to boiling, vapor lock and other heat related issues, so there is no one, magic solution, however several small solutions can add up to improve the situation. Your addition of a heat insulating carb spacer was a good step in the right direction and replacing the rubber hose with a metal line will be another. When you make the metal line, you will want to give as much clearance from it to heat holding things like thermostat housing, water pump, intake manifold, heads, etc, as is feasible. I've seen some folks wrap their steel fuel line in crinkled up aluminum foil as a heat sink, but I'm not certain that helps much, but...... every little bit can help. And of course, make sure your float levels are set properly. I'll bet dollars to doughnuts that I'v covered most, if not all of what you've been experiencing. Been there, done that, got the t-shirt!
HTH,
Gene

 

[Falcon79]

Good post Gene!

 

[jerthemost]

Great info Gene thanks!! That helps me to understand the process a little better. I am an old retired engineer and can usually figure anything out if I can get enough good info.

I can understand having the heat problem but it's just strange that i suddenly started having a problem when it's cool. Yesterday I started it 5 times throughout the day and it started right up everytime. Did not drive it just let it run about 5 minutes each time. This morning I tried to start it and it spun about six times and I didn't think it was going to start so I went to turn it off to check the choke and it fired up. But it took several spins of the starter which is not normal for this car especially after not having been heated up yesterday. Our temps last night got down into the high 60's or about 70.

So it appears that there was no fuel in the bowl this morning. Here is a thought.... the car is parked on the west side of my house and even though it gets some shade late in the day could the sun late in day be heating up the engine compartment enough to boil out the gas even when the engine has not run and been heated internally? I will park it in full shade today and see what heppens in the morning.

Another thing..... the cold start problem started Tuesday morning. Monday I was out and stopped at a Shell station for gas. Their pumps don't work well with this old car but was on empty so had to get a couple gallons. When I tried to start the car it was hard to start which I thought was the heat starting problem even though I had only gone about 5 miles and engine temp was 180 when I turned it off. That got me to my normal station but only got about 3 gallons was in a hurry. The next morning the car did not want to start. There has been another 8 gallons put in since then though and the problem is still there although not as bad as it was Tuesday and Wednesday. Could the Shell formulation be a problem maybe?

 

[bartl]

If your float bowl is emptying on a cold (been sitting for a few hours) engine you probably have a leak. In the morning if the bowl is empty, remove the air filter and open the throttle plates and look to see if the base of the manifold is wet with gas.

 

[jerthemost]

I think i have the cold start problem figured out because now it doesn't want to start hot or cold. Twice it would not start and just as i went to switch it off it fired up. That was just as the key was moved so obviously an electrical problem. It may be a bad ignition switch but i put in a new one 2 years ago but it could still be going bad. I will put a jumper from the battery to the coil this morning and try a start and see what happens and post the results. I actually rewired the system so power to coil goes thru a relay to take load off ignition switch so could be the relay too.

 

[bartl]

Okay, I know EXACTLY what the problem is.....

On the starter solenoid there is a small wire "I" terminal. That terminal energizes with the starter to provide a full 12V to the coil when CRANKING. If this wire is no longer connected or the terminal is dead during cranking, you will only be firing the plugs when the key is in the ON position, not the START position. That is why it catches the moment you let off the key. I had an '80 F250 with a bad ignition switch that did the exact same thing.

 

[jerthemost]

I know about the terminal on the starter relay. But I do get full 12 vdc to the coil because i bypassed the resistor wire when I bought the car 2 years ago. It was only giving me 5 volts so i did away with it. But i think i found the cold start problem anyway. The ignition switch gives you power in the run and start position so i use that wire to energize a relay that puts 12 vdc straight from the battery to the coil. Yesterday i changed the relay out and found one of the connectors on the relay a little loose. I fixed that too and now it cranks first turn or 2 when cold. Don't know why the car would start when i let off on the switch a bit but it's fixed apparently.

Now i have to fix the hot start problem or the car goes up for sale. Yesterday was the worst ever and my wife was so pissed she said sell it. I have about a week to fix this or the car is gone and it's atually her car.

I drove 25 miles to town, outside temp was in high 80's. Got stuck in traffic about 10 minutes and had to turn off the a/c temp keep creeping up. Got thru that traffic and hit a stop light and temp got up to 210 before i started moving again. Once air starts flowing the temp goes back down pretty quickly. On the highway at 55 it runs about 180. I stopped at a mall shortly after the light and temp was down to about 190. I parked in some shade and raised the hood a foot and let the engine compartment cool for about 45 minutes. Because of residual heat the temp went up to 210 but came back down to 160 by the time i was ready to leave 45 min later. It started on the second spin with no problem.

Drove to another part of town and in traffic it got up to 200. I stopped at a bank and switched off and did not raise the hood. Residual heat got up to 220. After about 15 minutes it would not start. It would act like it wanted to start about every 6 turns of the starter but not catch. I raised the hood to let it cool and when it got down to 190 it started. Still took a couple of spins but did start. I had to go home becasue i was afraid i would get stranded. I re-routed the gas line and wrapped it with tinfoil. It does not get close to the engine now. It appears to me that if the engine stays hot enough long enough it boild the gas out of the carb.

When i got home yesterday the engine tried to catch back up and run when i switched it off like engines use to do when we first switched to un-leaded gas. It has never done that before. Maybe this tells some of you experienced guys something.

My heating up in traffic was worse than last year and the hot start is worse than last year also. I have a new 4 core aluminum 24x16 radiator on the car with the mechanical fan and 2 - 9" electric fans pushing. Exact mixture of distilled water and anti-freeze and a bottle of watter wetter. Ever since i had the edelbrock stuff put on the car runs hot in hot weather. I know this is a different thread ad i did post it last year but never found a solution to running high temp. I am thinking now about replacing mechanical fan with 2 - 12" electrics and shroud from Derale (4000 cfm total). Anyone out there with any horsepower to speak, of running electric fan?

 

[jerthemost]

I think i have it figured out. It is definitly fuel boil over and research points to gas with alcohol in it. Ethanol has a much lower boiling point than gasoline. I read many articles pointing out that gasohol causes lots of vapor lock and boil over problems. Experiments i ran the past few days prove it out. If I can keep the engine from going over 190 degs due to residual heat when the engine is off I have no problem starting.

Solution....... I am going to install a dual hi output fan system from Derale. It has 2 - 14" electric fans putting out 2000 cfms each and has an aluminum shroud. I will wire it with a thermostat and time delay relay to keep running after the car is turned off hopefully keeping the temp of the engine down to 190 at least. An expensive fix but hopefully this will also fix my running hot in traffic problem and I will be able to ride in comfort with my a/c on. Will post results when I get it done.

 

[horseballz]

jerthemost,
I wholeheartedly agree with your assessment. The difficulty I see with your solution is that even though the extra cooling of the fans will drop the temps in the radiator (and likely overall engine compartment), the water/coolant stops circulating when the engine is turned off. This still leaves a bunch of heat trapped "inside" the engine and the coolant in it. The real solution would be to keep the coolant circulating after shut down while the fans are also on. The only way I can think to do this would be an electric water pump. While I see lots of folks using them on race cars, I'm not sure of the durability/longevity for street use, not to mention they are not cheap. It's sure a tough battle with crappy fuel. Your proposed solution will quite probably improve you in-traffic situation and just "might" be enough to put you into the "OK" zone with regards to fuel boil-out and/or vapor lock. FYI, many folks here claim to have had very good results/easy installation of the Taurus or Lincoln Mark VIII fans. They move some serious air and are easily and fairly cheaply found/repaired/replaced. Either way, electric fan(s) are going to require a pretty healthy upgrade to several parts of the electrical system.
>BIGGER alternator
>BIGGER wire from the alternator to solenoid
>A fairly heavy duty relay with associated heavy duty wiring from the battery side of the solenoid to provide power for the fan(s).
My Thoughts,
Gene