1975 1.8L Ljet injection. Car is hard to start. It takes 3-4 tries and some time a shot of starting fluid. Fuel pressure gauge reads 30 lbs. in engine compartment. The rpm rises to 1800 rpm for about 15 seconds, then the idle hunts between 500 rpm and almost stalling out. After the engine warms up it runs and starts as normal. Vacuum hoses are tight. Comments?

Aar?

Gasoline filter will allow pressure to build, but will limit flow. Check the injectors and make sure they are clean and flow properly.

So much to test for, but in my opinion (and I just reinstalled L-jet recently and have gone through every conceivable issue) there are two pieces of equipment that I think are essential to diagnosing L-jet issues. A smoke generator (make your own after watching some YouTube vids) and an AFR ($100-$200). Of course a voltmeter, too.

Read up on Malcolm's posts about his recent issues. Has it always run like this or is this a recent issue?

While hoses may be tight they could be split somewhere. The smoke generator will tell you if and where you have a vacuum leak. The AFR will tell you if you're running lean or rich.

Assuming that it ran well before and this is recent and no vacuum leaks, I'd check the CHT first. Just check to make sure it's plugged in. Hard to see if it is the original wire harness because the connector has a sheath. When the engine is cold the CHT plays a huge role in the mixture. If it isn't connected or crapped out it won't richer the mixture. That leads to lean/low idle. The CHT when warm doesn't have as much effect.

The AFR will help you in the event everything is working as advertised but the AFM needs to be adjusted.

If the cht is unplugged, it goes full rich. Not his problem. The aar stuck closed will not let in auxiliary air (the aa in aar) when cold to compensate for the extra fuel added by the ecu from the signal from the cht.

Geezer, unplug the hose from the out port of the aar and start the engine cold. If it idles up and runs fine cold, then the aar is faulty.

Checked the AAR regulator with an ohm meter and it was right on at 30 ohms, valve was open when cold. The temp head sensor checked out at 280k. Sprayed some starter fluid around the intake runner hoses and the idle picked up. I am going to replace the hoses, intake gaskets and injector seals in a few days and see if that solves my problem. This problem started a month ago, before that it ran like a champ. Guess it's time for some tlc.

I've found the same condition on occasion too: either an air leak or a weak/broken connection St the dual relay. I disconnect Air hose lines one at a time, plug with rubber stoppers. As stated above, the small hoses can crack and leak as well as a plastic T fitting.
The connectors at the base of the dual relay can back off just enough to can that problem. Can be hard to see if the plastic base is installed

Installed new intake runner gaskets, intake hoses, and new injector seals. I checked the injector plugs 3 times to be sure they were right. Checked the cht sensor by grounding the harness connector to the battery. Swapped out the dual relay, nothing changed. Swapped out the AAR valve, nothing new. It needs starting fluid to get it to start. Then it will restart with no problem . Fuel pressure was 30lbs. at idle when it ran before. It starts and then stalls out. After all the work, it's worse, not better. Where do I go rom here?

Sound like a bad connection between the dual relay and AFM. If I disconnect the AFM from the harness it does the same thing: starts up, then died

See if the fuel pump is getting 12 volts after it dies; that will tell you whether the AFM to dual relay connection is good

This is way out of spec

Head temp spec is 2500 to 3000 when cold. Correct me if I am wrong. I bypassed the CHT by grounding the CHT lead from the harness to the negative battery post and nothing changed, so it is not the CHT.

280k ohms > 2.5-3.0k ohms, still out of spec.

The CHT would never be at 0 ohms, the engine would be damn hot for the CHT to be 0 ohms. Jumping your disconnected CHT terminal to battery ground would simulate a 0 ohm CHT condition to the ECU. I know the computer is robust but shorting this sensor wire to ground can't be all that healthy for the ECU.

Also, grounding the end of a wire while observing for a change in engine performance proves nothing. If there is a bad connection within the harness, or a bad pin at the ECU plug, your ground at the end of the wire will never travel the full path and make it to the ECU.

When you remeasure the resistance of the CHT sensor, measure the resistance from the ECU connector between 13 and 5. Also state the temperature along with your measurement. Since you are doing that, might as well check the resistance between pins 13 and 16 and again between 13 and 17. All measurements should be equal to one another.

I checked the connection from the AFM to the dual relay circuit 1-36 and 4-39 shows continuity. Checked ECU to the CHT #13 to 5, 16 and 17 and they all read 2691k at 63 degrees. The engine needs a shot of starting fluid to start. It goes to 1800 rpm for about 20 seconds then drops to 0. It will restart with no problem, but I need to keep my foot on the gas to keep it running.

Could he flap in the AFM be sticking and not keep the fuel pump running?

Something is not keeping the fuel pump running once it starts so it will idle.

What would cause it to need a shot of starting fluid for the initial start up?

Tested AFM:

pins 6 & 9 200-400 ohms 282

pins 7 & 8 120-200 ohms 199.8

pins 6 & 27 2k ohms 2510

pins 36 & 39 infinity ok

Pulled a spark plug and it was white/tan, normal

Where to next?

I don't think there is anything majorly wrong with your system. A low idle will kill power to the fuel pump, it's important to have the idle set correctly.

You tested the AFM earlier, when testing the fuel pump contacts (pins 36 and 39) you were instructed to move the AFMs' flap. Did you notice any drag or areas of catching as you moved the flap?

I think you need a good tune up. If it was my car, I would start with a valve adjustment. I would then test the vacuum canister on the dizzy to see if it holds vacuum then re grease the breaker plate. Pull a vacuum on the dizzy's canister, and verify by watching the arm moves the breaker plate smoothly. Next, adjust the dwell angle so it's spot on. From there, I would verify and adjust the timing.

After that, I would pull the bleed screw from the throttle body and flush the internal passage with carb cleaner along with the butterfly and insides. Next, set the idle, follow exactly what the manual says to do. Once the engine is running, spray starting fluid around the oil tower assembly, fuel injectors, intake base gasket, intake plenum, throttle body rubber doughnut, then the rubber S boot. Observe for any change in engine RPM as you spray these areas.

If you still have a hunting situation, I would suspect it's a lean idle hunt. I've been seeing a trend with today's fuel formulas causing our engines to run lean with the stock AFM settings. You will need to borrow a mobile style air/fuel ratio gauge before you attempt to make any adjustments to the AFM. Contact Malcom2, he has a bible of the AFM (pdf form) which will help aid you in adjustment.

I really feel you should attack this problem methodically by starting with a basic tuneup.

Thanks everyone for taking the time to post replies. I replaced the O ring on the oil filler cap, found a slight vacuum leak. Then I removed the Idle adjustment screw on the throttle body and sprayed some brake clean inside as Tim suggested. I tightened the intake manifold bolts, and it started right up! Adjusted the idle. The idle holds steady and fuel pressure is 30 lbs. Chasing vacuum leaks will drive you nuts!

I don't usually comment on running faults with FI on the 914 because I have never worked on one with it.
I do know that nearly every older car I have bought with FI has had some sort of air leak from major to minor,I always do an electrical tune up first,then start looking for air leaks,it makes no difference if its L jet,D jet,CIS or Motronic they all run poorly with leaks ....to often certain component are blamed before the basics are sorted.
I remember it used to be very common for mechanics to say..."oh well it must be your computer then" because they didn't know s#it about FI.