I don't know if it's relative or not but when I got this car a week ago I had no other choice than to drive it home (300 miles) in the pouring rain. Today we took 'er for a ride. When I go into a left curve it cuts out REAL bad like it's starving for fuel. Right turns or straight, no problem. Just a hint of a miss. I just think it's very strange. Misses really bad on left turns. Any ideas? Thanks, Roger D.
'74 2 ltr.

Does it have the plastic engine water tray?

Injected or carb'd?

Points or electronic ignition?
B

I don't even know where to look for the plastic engine water tray. It's a stock injected engine with points. 73,000 orig., miles. I do know that it did not have a single miss before we drove it for 6 hrs in the rain. Im just puzzled why it mostly misses when turning left.

The tray mounts to the engine lid. It probably has it given the area that it came from.

My first thought: single wire for the Aux air regulator is shorting out against the body of the AAR in hard turns. This screws up the power for the coil.

Low mileage car: rust in the tank from sitting. You filled it up and washed everything down.

Still thinking.


B

Brad...yes, it has the water tray intact. Any reason why it might be misses badly only on left turns? Shouldnt it be all the time. Especially if the fuel was dirty????

dude check this out.

okay, off of your tachometer, you have a BLACK wire with PURPLE sripe coming from the back and going to the coil....this is what reads the ignition pulses. Okay. When you make turns, sometimes this wire catches on the steering column and if its chafed, it gets grounded. If the points are grounded, no sparky which equals no runny.

b

It may be rust washing around in the bottom of the tank. The pick ups in the tank are on the bottom right hand side (left turn.. everything washes to the right)

A few good bumps and it will loosen everything in the tank.

This is easy to check if the car is currently low on fuel. Crack the gas cap off and shine a flash light straight down into the tank. The pickup is directly below the cap.


B

Is your coil loose in it's mount? if so it may be moving around and shorting out around corners. If it is, fix it quick that loooong section of wire is unfused through the ignition switch, ask me how I know.

could be that too.

or maybe your flux capacitor has gone out, but my FLAPS says they are NLA.

b

Check your injector connectors. They can work loose (they were never all that tight to begin with), and pull partially out of the injector in turns. Nate had this problem on his 914 once, and I had exactly the same problem on a D-Jet Type 3.

I just shined a light into the tank filler neck. Nothing really noticeable around the pick up on the bottom of the tank. hhmmm??? Ok...I'll check the coil mount and wires. This is my first 914 so forgive me please...where would I find the injector connectors?

Cool. Eleminated the tank issue.

I would look at the coil next. They are notorious for coming loose and touching the tin (if yours is mounted on the engine tin)

I'll find some pics for you showing the injector plugs.


B

coil mount
Wires going to coil..all of them in the engine bay.
Injector wires.
Injector grounds.
FI grounds.


Rich

Ok...I just checked the injector connectors...all tight. Coil....securely bolted down. Didnt see any frayed or loose wires to or from coil. Emissions hoses all connected tight. Hmmm.???

What are the "FI grounds"?

Coil may be secure, but what about the wires leading to it? It doesnt take much to have a connector loose on the coil connector.

B

If you are using a blue coil, the clamp may be nice and tight, but you can move the coil around as they are a little slimmer than a black stock coil.

Coil is a black one...it's tight. Wires to and from coil are tight. Im puzzled!!

check to see if your TPS is plugged in securely, it plugs into your throttle body.

Does it immediately start missing in a left hand corner, or does it take a little time?

Could it be a loose fuel filter flopping around and kinking the supply line?

If the problem seems to act quickly as in immediately when turning left, I would suspect an electrical short of some type (more than likely in the ignition circuitry).

A wire may be intermittently touching a ground when the car is in a left hand turn while it is not while going straight or turning right.

The intermittant problems are the hardest to diagnose. Have you tried wiggling wires/connections while the car is running?

Does the "miss" happen while parked and turning the steering wheel to the left? Or does the car have to be in motion for it to happen?

Is the battery securely fastened down? Is there any way it may be shorting on something or pulling on the cables in a left hand turn?

Aw geez..help!! What's the TPS and is it under the air cleaner somewhere? Told ya I was knew to 914's. I know 356's upside down and backwards but this is new to me. Thanks for everybody's patience.

yep under the air cleaner, the TPS is a trottle position sensor - kind of like an acellerator pump for FI. It plugs in where the throttle plate is, it is a long shot but worth a look (general failure is bucking).

On a stock 1974 TPS (Throttle Position Sensor) is located on the Butterfly Valve/Throttle Body. It is in very close proximity to where the air cleaner meets the Throttle Body. I doubt this would be your problem as it is only used for enrichment during acceleration.

I just had another thought....

The MPS (manifold Pressure sensor) is mounted just below the battery (I believe on the battery tray support). Follow that vacuum hose toward the air plentum. Check this hose for any breaks/cracks. If there is a broken or cracked vacuum line, and a cracked line moves (opening the crack) in a left hand turn, the MPS would be fooled and the car would run crappy.

You could check all your hoses for cracks or tug on them gently to see if you can reproduce your "missing".

74 2.0 liter is djet FI system.

You have each fuel injector is individually grounded.
(FI grounds)

You also have a head temp sensor in the passenger side head, just below the rear spark plug...if that shorts out, you will have some very odd things happen...

Find that, yu can un plug it and test the cylinder head temp (CHT) it should ahve a cold reading and a hot reading...they should be very different (I cant remember off the top of my head, but these are read with an ohm meter)

You have a manifold pressure sensor and a decel valve mounted under the battery and bolted to the side of the battery tray support.
the MPS has both electrical and vacuum connections...

If the MPS vacuum is unplugged, it will run like a pig.

The throttle body position sensor ...the name kinda speaks for itself...This one can be removed, opened up and cleaned....the electrical plug needs to be cleaned out also.

Fule injection points are in the distributor, in the bottm of it...they also have an electrical connection...needs to be secure...

Under the air cleaner...using one of the upper case bolts, you will find your FI grounds...

There is a funky multi tabbed thing attached to one of the top case bolts...this has lots of brown and white wires connected to it...find it..
Take off all the connectors.
Take out the bolt and clean the multi spade thing, along with the bolt...
Then clean all the ends of the brown and white wires...
Make sure all the grounds are clean and re-attached.

Rich

Ok...see you guys later...you've given me lots of stuff to look over. I'll report more tomorrow. THANK YOU!!!

Roger D.

I've got a hunch I know what it is.

With the engine idling, grab hold of the fuel rail (metal tube) and wiggle it slightly. Does this make the engine stumble ? The short tubes from the fuel rail to the injectors are pretty easy to pinch, and this will definitely make the engine buck; it can be dependent on RPM and on cornering, so it can be real hard to track down. Fortunately it's a simple fix - just replace the fuel lines. In fact, replacing the lines is a nice, quick, satisfying project that will make your 914 much less prone to catastrophic fires. If any hoses are brittle or show any signs of cracking, do it now.

HTH,
jeff

Most likely an electrical connector or connection is intermittent somewhere.

What I would do is open the engine compartment with the motor running and start wiggling wires, listening for any changes in idle speed. Try and wiggle every wire related to the fuel injection system or ignition system including the spark plug wires. Hopefully you will find the loose or intermittent connection.

Demick

No NASCAR for you!

Ok...I've gone thru and checked wire after wire and all connections. Nothing obvious. However; I did pull the coil wire out of the distributor and the socket the wire fits into has a lot of lite green powdery stuff like corrosion. Im going to get a new cap and coil wire and see if that makes a big difference.