914 for Dummies 1974 1.8 wont run

[L-Rustronic]

Hi all. I am not a mechanic and this is my first attempt at restoring a car. I picked the 914 because I have wanted one ever since I was a teen. I know absolutely nothing so I am looking for some guidance. Sorry if I am dumbing down this post.

Here is my status..... I have a 1974 1.8. It turns over and will start with starting fluid and will run for a second or 2. I have a new battery, new distributor wires, new spark plugs, a new fuel pump and new fuel filter. Without starter fluid it just cranks, but does not fire.

Help.... I have the Haines manual and about 3 other ones, but they are too technical for me. Can anyone point me in the direction of a 914 for dummies troubleshooting guide or offer my next steps to getting this car running. I am dying to drive her! Thanks.

[Mats]

Sounds like a fuel issue of some kind...

How old is the fuel in the tank? Has the car been sitting for a period before you bought it?

[Jrboulder]

1. How old is the gas?

2. Are there any disconnected wiring plugs or hoses?

3. Are there any cracked hoses?

4. Is the plug from the fuel injection wiring harness to the ignition coil still plugged in?

5. Does the fuel pump turn on when you open the flap in the air flow meter a little?

6. Use a noid light to see if your injectors are being triggered

7. Check fuel delivery rate (out of fuel pressure regulator) and pressure (at fuel rail)

[beatnavy]

I take it from your screen name that you are aware that it's L-Jet FI (assuming that it hasn't been converted to carbs). I agree with the others' suggestions - it's fuel / fuel delivery related, but there are a lot of variables in that grouping.

I would recommend trying to understand L-Jet if you're going to own and work on this car. This manual: Tech Manual L-Jet 912E is a great resource, and has a troubleshooting table on page 9. It's for a 912 but you can use it too. It's off of Jeff Bowlsby's Tech Notebook, and if you search on that page for "L-Jet" you'll find additional resources.

I didn't know much about D-Jet until I had to dive in and learn on my 1.7 (now 2056), but a lot of reading and experimenting and now I'm comfortable with it. You can do it. It just takes some time.

EDIT: Oh yeah, and don't be afraid to keep asking questions - the more you learn, the more specific your questions will be, and the greater help we can be. Having said that, I personally don't "do" L-Jet (learning one obsolete FI system is enough for me), but others can help.

[L-Rustronic]

THanks guys for the replies. The gas is not old, only a week or two old. I drained the old stuff before I changed the fuel pump and filter.

According to the vacuum hose diagram, I should have a hose connected from the fuel pressure valve to the decel valve. For the life of me I cannot find a decel valve, so that hose is not connected to anything.

[Mark Henry]

#1 in an L-jet that's been sitting is to pull all the injectors, with a blunt pin push on the pintle in the injector tip. You should feel a slight click, a bit of give. Doesn't take much effort, if it's rock solid the injector is seized.

Then new hoses fuel and vac, new oil cap gaskets (2).
I'd also remove and clean out the gas tank.

[Dave at Pelican Parts]

BTW, if you are a total novice, you can do worse than to find a copy of the John Muir VW book, colloquially known as the "Idiot Book". Now, Bugs are not 914s, and the two engines only share a couple of parts, but there are definite similarities and John does break down things into very bite-size and very readable pieces. (Likely due to his original target audience... )

If it runs on starting fluid, then you have spark and at least half-decent compression. So what you are missing is likely fuel. The folks above have some good ideas to check.

The hose from the fuel pressure regulator is intended to "see" manifold vacuum. The connection at the Decel Valve is almost certainly just a convenient place to get a source of manifold vacuum.

With a 1.8, you do not want air leaks getting into the manifold. This will be air that the FI does not know about, so it won't add fuel to go along with it. Large vacuum leaks will result in lots of "unmetered" air (sometimes called "false air") and there won't be enough fuel to burn properly.

After you crank the starter for a little while, is there a smell of fuel at the tailpipe? If not, that's another hint that you don't have fuel going into the engine.

--DD

[L-Rustronic]

Thanks Dave. What is the best way to test if the fuel pump is working? It is new, but I am wondering if I am getting power to it. I dont hear it run, and there is no fuel coming up the hose from it into the engine well.

[beatnavy]

The little I do know, or think I know, about L-Jet is that the fuel pump is supposed to run when the ignition is on and the air flow sensor is activated. The sensor detects that the engine is sucking air and that signals the pump to get going. Jrboulder mentioned it above as #5. With ignition on, if you open the air flow flap slightly, you should then hear the fuel pump. It not, you've got a place to start.

It's all in that step-by-step L-Jet troubleshooting document.

[r_towle]

Hi,
To test the fuel pump, disconnect the AFM (air fuel meter....big box) from the intake air filter so you can stick your finger inside the intake side and open up the flapper door.

Turn key to run
Stick finger in and open door.
Do you hear the fuel pump?
If no, you need to check all the fuses and th two fuel pump relays....those have special tests.

Rich

[L-Rustronic]

Pump works. I have disconnected hoses in several places. I cannot find the decel valve so I have at least 3 disconnected vacuum hoses. Would that be causing it not to start?

[Jrboulder]

Time to post some pictures

[L-Rustronic]

Will do. Can anyone recommend which fuel pressure tester fits the 914?

[Dave at Pelican Parts]

Originally Posted by L-Rustronic

I cannot find the decel valve so I have at least 3 disconnected vacuum hoses. Would that be causing it not to start?

Yes, it certainly could. Any air leaks into the manifold of an L-jet system mean that air is getting into the engine that the FI doesn't "know" about. (This is called unmetered or "false" air.) More air with the same amount of fuel means a leaner mixture, which typically results in poor idle.

However, three hoses completely unconnected is a whole lot of false air, which can easily make the mixture too lean to reliably fire.

--DD

[L-Rustronic]

Can anyone recommend which fuel pressure gauge has an adapter that fits that tiny opening on driver's side rail?

[Dave at Pelican Parts]

Any one that hooks up to a ~5/16" hose which can then be clamped over the branch that has the opening in it.

--DD

[L-Rustronic]

Anyone know where I can buy a Deceleration Valve for my 74 1.8L?