My 914 still doesn’t start regularly. I turn the key and every time I heir the buzz my guess is the D-Jet fuel pumping and then it might start or nothing happens. Once it starts cranking it will start just fine. Here is a list of what I’ve done. What am I missing??? What could be wrong?

New battery
Clean the connections on the battery
New ends on the positive wires to the battery
New ignition switch
Clean and replaced connections on the starter solenoid
Cleaned ground strap connections from tranny to trunk

Kevan

Are you saying that nothing happens when you turn the key?

starter is toast ...

i had the same problem. brand new starter fixed it.
Andy

I use to have this problem all the time and still have it today. I know for mine I was cranking mine over for to long and to many times in a row and the starter gets really hot. and the life span goes down alot. But over all if you take it out and bring it to someone to test the problem may be that is drawing to many watt's away that is what my problem was then I got a new one stuck it in and it work fine for the first few days but I screwed this one up to by just over using it.

[QUOTE] Are you saying that nothing happens when you turn the key?

Only the d-Jet pumping fuel

"starter is toast ..."

How could the starter be toast because when it ever decides to crank it fires right up. Anyway I think I have an extra starter. I'll put it in and see what happens. Thanks

Kevan

starter. brushes are worn.

Could be the solenoid contacts too. I went through this too.
I put in a rebuilt starter AND a relay kit. No more problems.

i know you guys are all saying starter, but could it be a bad fuel pump? with my 914, i used to get a buzzing sound when i turned the key, but it wouldn't consistenly start. one day, it didn't start at all. turned out it was a bad fuel pump. replaced that and i had no problems. until.............we won't get into that right now.

I was just posting something on this on Rennlist... so here is a diagram followed by photos of a relay set up for your starter.

- Dave

Photo 1

Photo 2

thing about the relays is, you just put a band-aid on a problem you can't find.
will work (at least for a while) but won't fix what's actually broken.

if in good working order, the starter circuit doesn't need a relay ...
Andy

Bandaid?... maybe...

Lots of things that aren't needed are still an improvement. IMHO any circuit in a car that draws a fair amount of current is improved when you add a relay, unless you like lots of current running through switches on your dash or in the key switch...... bonus is less voltage drop to the starter... In my case I never had a problem with that starter again... didn't have to buy another starter...

If you need a new starter... buy one... then add a relay and save your 30 year old key switch.

yes, that's what i call a bandaid

so, your starter was giving you problems cause it wasn't getting enough juice to turn nicely.
you added a relay to give it moah power. worked great.

still didn't fix the problem of not getting enough juice to it without the relay tho. <_<

somewhere in there you still have a little electrical gremlin lurking ...
that was my point. bandaid, here, i said it again.
the circuit was designed to work without a relay. if you need one, something IS wrong.
Andy

Cactus....it's amps, not watts......

As to starting...it's normal to hear a fuel pump buzz....no buzz no pump. Some fuel pumps will have intermittent shorts that will work once the engine is running. That's why it will start after a few cranks....it is using the residual pressure in the fuel system.....

Now a starter that drwas a lot of AMPS will heat due to impedance in the wiring. This can be from bad grounds or corrosion in the postives leads.....

Best to check the wiring before replacing expensive, non-returnable electrical components....

Hey Kevan...

That 6 mount you looked at was ordered for you...

B

Andy, normally I would agree with you, but the starter circuit pulls SEVERAL AMPS through a tiny wire that goes more than a couple feet up to the front of the car, then through an ordinary ignition switch. This is a bad design.

There are bandaids, and there is also lack of margin in engineering design.

This is a little of both.

yes. maybe.
still, it works well if in good working order.

point is (still), if it's not working right, something is wrong!!!

whatever the problem is, fix it first, THEN install a relay if you wish ...
Andy

I will let you know when my ignition switch (or whatever it is that is going bad) craps out, but it's been 6 months now and not a single failed start.

Band-Aid. Fix the problem. Ranks right up there with people that run extra wires because something doesnt work instead of fixing the actual problem.

Yes a relay works.. I have also seen them do ZERO after being installed.

No matter what happens the little yellow wire has to supply voltage to the starter solenoid. If it isnt enough then there is a issue between the ignition switch and the starter. FIX IT.

I even had a reputable shop tell me they install relays with every starter purchase so people with old 911's/914's dont return with a starting problem later. They know the real issue lay's in the ignition switch but people wont pay to have it done correctly... Band-Aid.


B

No matter what it's going to make the ignition switch last 10x longer once the relay is installed.

Most relays have diodes on them to kill high voltage kickback that will otherwise slowly eat away the contacts of the switch. The reduced current helps a lot too.

Well so far.. I have replaced 4 ignition switches in 17 years of 914 work and installed NO relays (all the cars are 28 years old now...)

Band-Aid... ha ha..

I know what you are saying.. but I'm tired of the BS fixes I see people using from time to time.

The 74's are a different story. The yellow wire can become corroaded over time because of its location under the passenger seat. It is subject to water soaking if any water sits on the floorboard for any reason (again..fix the problem.. replace the yellow wire in the harness from end to end)


B

Newbie here, What about after driving for a while,turn car off,finish errands,hop into car and she doesn't start? I've grown to hear it's a "Heat" issue.
Thus a relay is the answer.Had mind for over 20 years,no problems.Before relay,GRRRRRrrrr!No starting!

Brad,

I think you are exactly right. It sounds to me like the "yellow" wire is the culprit.

My guess would be a defect in the logic circuit under the passenger seat is responsible for the crank - no crank condition described.

What I think you are describing is the problem of a vapor lock heat soak condition. (where it will crank but not start) This is usually solved by relocating the fuel pump up front under the fuel tank where it won't suck air bubbles.

In my experience (30+years with these cars) when the car won't crank only when very hot, it is a starter issue. (That's why if you whack the starter, it will sometimes start cranking) If it is a sluggish cranking, you need to check the grounds and the battery condition. On rare occasion, I have seen positive battery cables that were very hard/brittle with high resistance and needed replacement (I think that was caused by a charging related problem).

Do you mean capacators? I am familiar with placing a capacator across the contacts of a relay application to protect the contacts (from arcing).

The diode thing is news to me. Please explain.

You put a reverse biased silicon rectifier diode across the coil terminals of the relay.

To do this, the negative side on the diode hooks onto the +12V side of the coil. The negative side is the one with the white band around it. In normal operation the diode has no effect since it cannot conduct current in the reverse direction. Diodes are like one way gates. They only conduct electricity in one direction - from their positive terminal to their negative terminal.

Here is how it works. When +12V is removed from the relay, a big voltage spike of several hundred volts appears on the terminals of the coil. This voltage spike is what causes arcing and damages switch terminals. The polarity of this voltage spike is in the reverse direction of the voltage that was applied. This voltage spike now turns on the diode and the spike gets shorted out at the relay before it has a chance to do any damage.

It was very hot!(Hot start problem)

Yes I used to have the vapor lock problems,but since I've built a heat shield(Wicked looking)
No problems.
But back to hot start problems,are you saying I'm going to have starter problem down the road?
The relay is just a a band-aid for now?

your starter is slowly dying ...

same happened to me. it'll do that for a few month and finally it'll stop working.

Andy

Really!
Thanks for the heads up!

Which two wires on the 74 do you need to cut and join to by pass the seat belt relay?

Kevan

The biiiiiiiiig yellow ones. One of them might have a red stripe on it. Make sure the joint is clean and tight, and use shrink-tubing on it to keep out water and dirt.

--DD

Something else we dont talk about (vapor lock crap)... route the heat from the passenger side flapper box away from the fuel pump. Do this with a small hose attached to where the "bell" normally attaches. Porsche tried to solve the issue with the 9146 by placing a hole in the center of the bell. When the flappers are closed it routes the heat out of the "bell".. and onto the fuel pump. When do you have the flappers closed.??... when it is warm outside.


B

For some reason I bought a hot start relay kit. Thought I might need it. I also bought a new starter, alternator all new ignition system. Doubt I'll need it. Probably run a new thick wire from the battery to starter/coil or something. Just to get the juice flowing.

I do NOT like mounting the fuel pump up front. You are pressurizing a 30 year old plastic line that was NEVER pressurized to begin with. Again.. Band-Aid for the true problem. I feel it could lead to lean spots in the running of the car because of pressure drop. Sure you can crank the fuel pressure regulator up... but the pump NOW has to push fuel over 13 feet to the first injector.



B

So are you saying that you'd rather have an injected pump at the rear? Would you move it from the stock front location back?

So the first time the diode sees your voltage spike of several hundred volts blows a hole right through your silicone diode and now the diode is fried and does nothing. Hmmmm.

Diodes don't like large spikes of reverse voltage/current. Capacators on the other hand are more like shock absorbers and will take the large surge when the contacts are opened. Have you never wondered what a condensor was? A condensor is a capacator meant to protect the ignition points for this exact purpose.

The later cars have different fuel lines for this purpose. It was easier for them to move the fuel pump that it was to throw away 103k passenger side flapper boxes that where outsourced and purchased before the car was built.


B

So people with 1975-1976 cars should (in your opinion) relocate the fuel pump? {Are you NUTS} Band-Aid? Why would the factory relocate the pump if there was no issue? The later cars even use the same tubing through the tunnel. It was meant for pressure.

When I relocate the pump up front, I use the 1975-76 pump designed for the task.

Also of note, it matters not how far you are "pushing" fluid horizontally at least the volumes that our tiny 4-cylinder cars require to be pumped. The static pressure back on the pump is only due to elevation, not horizontal distance.

This is simply physics and nothing else.

The cars I have at the shop dont run the same lines as the early cars (4 75/76 complete cars). I explained "my theory" on why the vapor lock issue happens and why they moved the pump later. I also know they moved the pump because the exhaust physically ran hotter with the Cat in place creating even more under body heat.


I should have been more clear (I dont move pumps to the front of cars that came with pumps in the back) I knew what year car Swood had (which has its pump in the rear).


Sometimes I answer questions knowing information about the owner and his car that the readers may or may not know. I have a bad habit of paying attentiong and recalling everyone/everything.


B

It was the god dam seat belt relay. Finally I can start enjoying my 914

Thanks for the help

Kevan