I have stated my question in a way to get the most responses/help/ideas possible.

when the weather is warm to hot and I have driven it for 4 miles or so, It really
wants to die. and then if i drive it any longer it will die in the hot weather.

THEN

after just waiting until (it seems like cools off - because engine if not running
it will start right back up and go.) in the hot weather.

I know others have experienced something like this BUT
I have never seen any answers that come close to my situation.

thanks for your help.
914 luva

Might help if you state which year model, engine size, FI or carbs. I'm assuming it is a 914.

... & then if folks would even list their 914s in the VIN data base on their own profiles at the bottom, then we could even try to look for it there!

TLI to help you I'm afraid.


Tom
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Vapor lock maybe? Where is your fuel pump located?

Based on the minimal info., I'm going to suggest starter solenoid.

Happy to help, sounds like it needs some basic maintenance.
All setup here if you need help locally.

Rich

i am not sure I really understand vapor lock.

but the fuel pump as well as everything else has not been relocated.
so the fuel pump is in the original location.

please explain vapor lock so I can understand PLEASE.

thanx so much

BTW: 1974 2.0 914 all original nothing hacked.
original fuel system and computer nothing changed out or upgraded.

I would like to keep it that way if possible.

so i hope i have answered all questions.

thanks so much for help.

also i am thinking when the car gets warm the fifth injector should shut off
because the car is started and warm but it keeps shooting out.

what do ya think of that idea?

Vapor lock, as I understand it, is when the fuel lines/pump get hot enough from engine and/or environmental heat that the liquid fuel starts losing its liquid properties resulting in the fuel pump unable to push it through the system. Or sumpin' like that. The "fix" in many cases was relocating the fuel pump from the engine bay so it wouldn't get all that engine heat.

You really need to tell us if it's carbs or FI you're dealing with here.

Edit: sorry, I see you say it's all original, so I'm going to assume FI.

umm on vapor lock... that makes sense.....
yes i have original 2.0 D-jetronic system in the original location (as is everything else)
that entire system works as documented.
ah ha now I understand why i have heard people say they have moved the fuel pump. but there must be another solution?

what else have you heard people do to solve this?

you have enlightened me on vapor lock.

thank you

I bought a 1972 1.7L, and that same day drove it 550 miles. On the mid point I stopped for a gas fillup and like an idiot, I turned off the ignition. Vaporlock! Would not restart for hours. So ever since all my 550 mile road trips the engine never gets turned off. 8-10 hours non-stop run time is fine for these engines.

I would love to try a 24 hrs LeMons style drive. Maybe Seatlle to San Diego to Dallas to Jackson Hole back to Seattle, non stop of course. And if that goes well, then maybe a four corners Seattle to San Diego to Miami to Boston to Seattle 10K!

Nothing to do with vapor lock and even though I don't have a lot of experience with 914s if i were you I'd replace those original fuel lines. At least the ones in the engine bay.
I have a 74 also and while swapping out the fuel lines the ones in the engine bay were so brittle they snapped in two like a dried twig.

Steve

"Nothing to do with vapor lock" meaning my reply to your post, not your issue.
Wasn't written well.

Steve

I agree with replacing the fuel lines. Watching your 914 burn is heartbreaking. I know, Betty and I lived it.


For your running issue, it really sounds like vapor lock. Gasoline boils at approximately 90 degrees Fahrenheit. The fuel pump for a 74 and older 914 is mounted right next to the heat exchangers. So when you turn the car off, the gasoline in the pump stops moving and the heat radiated from the engine and heat exchangers boils the gas in the pump. There is no pump in existence that can pump a gaseous substance. It has to be liquid. So you are stuck on the side of the road with no fuel pressure. If you wait until the car cools down, it will start up and run fine.

The reason this normally doesn't happen when the car is moving is because the gasoline moves through the pump before it can boil. But it can happen. Get in the desert with high temps and it would be possible to generate enough heat to boil the gas while it moves through the pump. It's possible, but highly unlikely.

Porsche realized this was a problem, and on the 75 and 76 914s, they moved the pump up front under the fuel tank. That's what I suggest you do. But don't do it with the stock fuel lines 40+ years of existence has made them brittle and prone to breakage. Pushing 30+ psi down old brittle lines could be disastrous. I suggest getting a fuel line kit from Tangerine Racing and installing it. It is invisible unless someone crawls under the car, so you won't mess up your originality.

Back in the day (1973) I had a new 914 and started having the vapor lock problem in the Minnesota summer. I simply added a second low pressure pump, a Holly if I remember correctly, at the gas tank end to always keep pressure on the line to the FI pump. Problem solved.

I would also recommend replacing the old fuel lines.

NOW let me point out something else.
someone pointed out to me that is it NOT vapor lock.. because when you start car let it run stop car and look at spark plugs they have soot on them.
so this means something is burning very rich... too much gas...
so the 5th injector (btw all injectors are new) is shoot too much gas and when car gets hot/warm it is SUPPOSED to stop shooting gas. but it does not and the car shuts off.

other idea is compression. this is the route I am going to research and look into more. it is my understanding valves have never been done.

One thing it could be is too much blow by. If all your vent hoses are connected to the intake too much blow by could be choking the engine. Try venting them to atmosphere ans see what happens.

This is what happened to my son's car. Short drives it ran fine (school and back) but anything over 30 minuets It would stall at idle and if you shut it off it would only restart after cranking for a long time with the throttle wide open. Once I vented both heads and the crankcase to atmosphere we got another year out of it before we had to replace the engine. (subaru swap)

I didn't necessarily think vapor lock was the prime suspect - but I was explaining what it is. Now that we know you have FI, it does sound like you're running way too rich. On D-Jet, that can be one or more things that include:

1. Fuel pressure set too high. Check fuel pressure to make sure it's ~29 psi.

2. Blown MPS. Test with vacuum pump.

3. Failing CHT or intermittently failing CHT circuit. This is my "favorite" as it's pretty common.

4. Stuck injector and/or stuck CSV. If you have new injectors, you can also just try disconnecting the CSV to see if that helps.

Here's a great resource for you:

http://members.rennlist.com/pbanders/djetparts.htm

That's got LOT of info on these components and how to troubleshoot. I read that page often. Start checking and eliminating variables and potential causes. If you do that methodically, you'll get there, and we'll help.

You know the other reason for overheating could be because your engine is full of mouse nests

Boston and a good condition and clean engine shouldn't ever have overheating issues.

In the seventies, my 73 1.7 would die while driving and I would have till wait till it cooled off. An "old man" told me it might be vapor lock and to get a squirt bottle of water and spray the pump the next time it quit. Sprayed it and bingo! Started and ran. Then a dealership mechanic told me they moved it to the front in later models. I moved it to the front and the problem never surfaced again. Vapor lock is for real.

when i installed the new SS lines i wrapped the lines(firewall back) and the pump in a heat blanket kinda stuff ,like header wrap but shinny on one side and its like a blanket..i just cut it and used stainless wire to secure it,,seems to work good and if i get a gas leak it cant spray on the hot headers ...good luck