Hey all, now that it is warming up I am running into some pretty intense vaporlock issues. I have the stock pump in the stock location for 73. I don't have time to run new lines and move the pump etc. Anyone try foil or insulating wrap or anything like that? I suspect it is from the line heading from the pump to the engine, but I may be wrong. I could hear the pump blowing bubbles in the gas tank yesterday when it happened (the starter solenoid gave up too so I was able to keep the pump running without the engine turning over). Pumping fresh gas through for a while was how I eventually got it going again. 0 fuel pressure while locked, as everything cooled I was able to get pressure again. I could hear the pump doing it's thing so I know it wasn't dead.

I should add that it only happens when I stop and let the car sit for a little while (minutes).

I rarely had issues last year but I only got the car running really good (thanks tangerine racing and 914world) very late in the season, October/November.

Had the same trouble. Used the aerosol cans that produce cold. Spray it on the metal fuel lines/fuel rails. Worked for me like a charm. Always carried a few in the frunck.
It was never again a problem after I switched to carbs. With the carb installation, I did leave the return fuel line to allow the circulation of cool fuel.

Great idea. I will definitely do that for future use. Where did you concentrate the cooling? Hoses near the engine or the pump and prior?

I use the electronics duster cans to cool over heated electronics (leaves no residue except frost if you over do it). Flip them upside down and instead of the gas, the liquid "freon" comes freezing things instantly. You can find them everywhere. I get mine from Costco.

I don't know where to spray for the vapor lock though.


https://www.costco.com/dust-off-compressed-...t.11228077.html

It's usually on the tank to pump side but regardless; 327's used to have this problem and back then being a broke assed teenager we'd clamp wooden clothesline pins on the line which ran infant of the engine and about 1/2" off of the engine. Terrible design. Or try running AvGas for a quick fix.

@emerygt350

you have my sympathy.

fridge cans sound pretty good. might have to get hold of some of those myself for regular summer driving in fry up world southern hemisphere.

You spray the coolant on the fuel lines and the fuel pump in the engine compartment. I'd get the vapor lock problem when stopped for a short rest break after driving in heat or on the freeway. The short stop allowed the heat to rise boiling the fuel. Eventually, it will cool to back to a liquid thus long stops never seemed to be a problem.

I kind of remember something about heat coming from heat exchangers causing vapor lock. With the heat off to car interior. The engine fan pushes heat out of the heat vent right onto the line going to pump and engine.
Do you have the black diffusers under floor pan for air flow?
Is the tin sealed between the top and bottom of engine?

Matt

Boy, does this bring back some memories.....ugh!

My first 914 was a 1973 914-1.7 which I owned when I lived in Phoenix, AZ for 3.5 years until I bought my first of two 1970 914-6s. (I still have one of them.)

I competed in my 914 1.7 at Phoenix International Raceway and Holtville (very hot).

I sympathize with your "vapor lock" situation as I experienced it several times in Arizona and in New Jersey (on a summer vacation). In fact, I was very stressed when it happened on the New Jersey Turnpike!

So, how I handled the situation:

I wrapped and zip tied 2-3 layers of terrycloth towel sections around the fuel lines and I believe the fuel pump area as well. Then I SOAKED them with water (ice water I had in a bottle in my onboard cooler of ice) so I would get some "evaporative cooling" when the car was moving. I would periodically stop to check them to make sure they were wet and pour on more cold water as needed. It worked and definitely reduced the occurrence of vapor locking. I would think soaking the towel before each of your sessions on the track would help you avoid the problem in the first place. (Take towels off when the conditions that cause concern for a possible vapor lock don't exist so normal cooling conditions are in place.)

So.....this is just my 2 cents worth as it worked for me in my particular situations....... Hope this is helpful.

Have appreciated the other suggestions that are being made...
Please don't hesitate to comment if my method isn't advisable.....

Best of Luck!

Cheers,
Margie

I actually had my early 914 vapor lock on the NJ turnpike. Stalled at 65 mph and I made it to the shoulder. I was 17, new to 914 ownership and had no idea what to do. Got it started after about an hour and made it home.

That is an interesting idea. I guess the only harm would be when you forget and the rag dries out and catches fire?

So you had a NJ turnpike experience as well as the age of 17........so glad you got it started!

Unfortunately when I had my NJ Turnpike incident I wasn't familiar or prepared for a vapor lock.....I was totally stressed as I had to leave my treasured 914 on the side of the freeway OVERNIGHT! I was so concerned that it might not be there the next day or might not have all of its parts (after warnings I had received). I even called the agency that was patrolling the NJ Turnpike and asked them if they could "keep their eye on it"....sure?....well thankfully it was there the next day and started right up.

Margie

I didn't have any choice other than pushing it home. Mid 80's, no cell phones, etc. I think pulling over on the grass helped it cool down faster and the sun started setting so the cooler air helped get me going sooner. Every early 914 I've owned had the same issue and Bob's '73 had multiple vapor locks during our drive in Octeenerfest. He's since moved the pump to the front.

Or else 914's just don't like New Jersey.

Just my 2 cents

After 25 years of wheel to wheel racing
Not fun or worth going to the track with a known issue

It’s not fun to fight with a car when you really need to concentrate on driving.

I won’t take a car with a known issue
Very much worth fixing the issue before going

yes - that source of fuel vaporization tends to be while the engine is running and the car is standing still. eg at idle at stop lights or standstill traffic. that hot air from the exchanger vent tends to collect under that area and the diffusers can't do their work to cause the air to be extracted. they only work when the car is moving.

source of heat after shutdown is radiant heat from the fan shroud casting and to some extent the heat exchangers. i believe its mainly the fan shroud. engine heat is conducted/flows to the magnesium alloy from the aluminium alloy/cast iron engine.
do this test yourself. the fan shroud will be cool immediately after shut down.
within 5-10 minutes its too hot to touch. takes about 20-30 minutes after shut down to cool again. it heats the line that runs from the tunnel to the pump and boils the fuel in there. and that fuel is not pressurized by the pump, its gravity fed from tank with maybe some weak suction (pumps are stronger out the pressure side than the feed side). if the pump is in original location.

on track @emerygt350 should not really have any problems. the hot air will be getting pulled out of that area.

i never have problems down here if the car is on the move during summer.
its when it has to sit for too long at the lights or get caught in standstill traffic that the fun might start. but not in winter.

you just have to work out a good way to keep the fuel lines under the car cool after shut down.

i don't think the engine bay lines are a problem.

a portable battery powered blower fan on the ground just in front of the back wheel and directed under the car might also work. blowing a bit of a strong breeze to help combat the radiant heat build up? you don't have to try and get under the car then to wrap fuel lines.

that

the older I get the less fun bandaiding things on site becomes.

also the pump relocation isnt that big a deal.

but if you insist on running as is at least pay close attention to your fuel being sure to only fill with ethanol free gas and keeping the tank filled to a higher level may help. Also be sure you dont have any winter gas in it.

all fuel is not the same and some vaporizes far easier than others which exacerbates the problem.

Do what the factory did as a work around. I have used this for years with no issue.

Go to my Classic 914 website and click the link for service bulletins. Find P213. Everything you need to know.

Yes, the car is fine as long as it is running. It's the heat soak after shutdown. I don't anticipate problems but I want it to start up after shutdown. Luckily it looks like cold weather Sunday. I will check out that p123 too. For the moment I think I will wrap those lines. Drove it 160 miles tonight through the hills on the interstate, no issues. Forgot to try and start it right away after I stopped though.

Just read that bulletin (p213), I think they already did that to my car ages ago, but the added hose fell off the heat exchanger and the insulation has disintegrated and is almost entirely gone from the fuel line. I thought that stuff was factory. Well, that explains the sudden issue, I found a huge chunk of it on the garage floor when I pulled it out after this winter.

Ok, very cool amount of work there Jeff.
Quite helpful

My fix was simpler, redirect divert or to point the other way.
But, I never saw that p213 article….so do that!

the factory fix that jeff b has on his website is neat.
def would help with the car running in traffic/standstill issues on hot days.

still leaves the after shutoff problem. which can persist for up to half an hour, depending on how hot the engine is, and how hot the day is.

moving fuel pump to front might help that. means its a pressurized line in those areas exposed to radiant heat. tends to boil a bit higher temp then.

fuel isn't helping. i think you guys have a higher ethanol content than here. talking about conventional blends, not E85. its in everything these days. but in limited %.

DEI has some great heat shielding products, some don't require disassembly.
https://www.designengineering.com/products/...leeving-tubing/

Hooking up the 2nd heat line to the fan like they did in the later cars might also help get heat out of that area.

Ah, I didnt notice that you dont live in "corn gas" country. By law the majority of pump gas is up to 10% ethanol here. Takes a bit of effort to find actual gasoline here.

I bought some of their gas line sleaving. Looks like I won't have to disconnect anything.

Maybe worth mentioning, if this is only happening after shutdown/sitting there may be a contributing factor of the intake air temp sensor heat soaking causing a lean condition as well.

Observed this when running a Megasquirt ECU on an otherwise 100% stock d-jet setup. Car would run but O2 sensor reported it was lean after hot restarts. Due to the location and solid nature and metal/metal contact of the air temp sensor heat from the intake manifold and engine makes that sensor real hot. On an 80 degree day after shutting down between autox groups the system was seeing intake air temps double what they should have been and leaning out accordingly until the intake manifold temps normalized after restart.

I would say 99% sure changes to your fuel supply should address your issues, but figured I would mention another interesting quirk of the stock d-jet sensor setup.

yes

you can get E10 here. thats the limit for ethanol blend. and it is sold as a distinct product indicating ethanol. all the rest is still petrol.

and the E85 for ethanol fuel cars.

makes a difference. a few years back heading up to bathurst for the 12 hour, one of our group made the mistake of filling his old falcon with E10 (its cheaper). it was a super hot day. 350km of misery and boiling fuel pump. he thought he might not have problems highway running. matters less in winter.

I am sure a lean mix won't help. Just read pbanders little update which has me thinking about that too. Before the race I am going to do the Ford solenoid fix, the insulation, and take a look at the engine compartment too. All my tin is good etc, and the engine runs nice and cool so I suspect all of the upper stuff is ok.

I can get pure gas here so I may go for that too. It will richen the mix a hair as well.

Just move the pump from the stock location to just above the air diversion fin on the passenger side "firewall" near the engine compartment.

You can mount the fuel filter there too. There are a bunch of threads on this.

I would take an afternoon to do this and avoid all the drama.


I ran my car like this in 130 degrees Palm Springs heat and it never vapor locked on me in that location.

ahh
i wondered about cars where i had seen images of the pump in that location.
thought it was something that was done stock in 914s pre 74.
but now i see its a mod?

Yeah, that is where mine is located. I mean it is only a few inches from the stock location but there is probably more air flow there.

That the P heat control valve blows hot, HOT, air towards the stock (rear) pump location when closed should be taken into account.

Yeah, definitely replacing the now missing heat duct outlined in p213

Anyone know if Lowes sells something like that?

@914_teener or @emerygt350 any pics of that install option?

When I am down there tomorrow I will take a picture.

Doh. Forgot to take a pic of the pump but you are not missing much. I didn't want to drill into the firewall so I suspended mine from a piece of sheet metal hanging down from the little flat bit that connects with the engine seal tin. I added a little aluminum foil pipe to the diverter valve and pointed that down and out. Put the really nice insulation from the above mentioned company on there. Couldn't get good enough access to use the sticky bits but nothing some zip ties couldn't fix. Also did a high quality fix on the other heat exchanger, and took a picture of that, in the background you can see the sleeves on the fuel lines. Click to view attachment

Ya know it's funny....I thought I did but think Tod did after he finished his. It was a while ago so that' when I could still crawl under the car with the back I had then.

Here's my thread anyway. I know there is a picture out there...good practice for your search skills. Here is my thread http://www.914world.com/bbs2/index.php?showtopic=102793

Everything went well at the race. No heat issues there or driving around. I think it really must have been the loss of the old insulation.

Didn't do too bad for autocross on all season radials. Here is my terribly matched group (dsp)

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And here are some of the other cars in my time range from other groups. Last is the novices. Notice cars like a subi 2.5 rs and a 2020 bmw 330i get a better pax than I do... Sigh.

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Glad to hear the car was up to the Chalon-ge…

I’ll see myself out, thank you.

hey thanks for that mate @emerygt350 .

you are confirming my theory that its the metal fuel lines i replaced the original plastic ones with that are my source of slight woes in summer. that is the bit that goes across the back of the cabin firewall to the fuel pump.

insulation wrap here i go.

That dei engineering sleave (14 dollars Amazon) is well made and cheap. One box is more than enough for the job.

That was pretty good....

Some nice pics from the race
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How big are these dudes, they make the teener look tiny!!

nice pictures!!!!!

+1 nice pics.
But the passenger with arm hanging outside the car would get you black flagged with the orgs I ran with.

Yeah, that was in grid. Definitely get yelled at on course.