76 2.0 d-jet. stock displacement, hydraulics, with smog removed and backdated exhaust to 74 2.0 SSI's with Triad.
Runs great. Pulls hard to redline in 4th with no missing. Idles 850-950 when warm. Starts up when cold just great and idles 700-800.
After running 10-15 minutes to town and going in the store for 10-15 minutes, come back out and turns over but doesn't want to fire. Pedal to the floor and turn over for 30-40 seconds and it gets faster and faster and finally fires up. Then runs great. If it sets for an hour or more , no problem in firing right up.
Searched here and the only thing I can see that may be causing this is the distributor plate spring(s)? The wiring is all fairly new, so I don't think that would be the problem. Checked all of the connections and they are clean and tight. If the dist plate is sticking in the full advance would that give me these symptoms and how would I fix that? Grease? Special type?
Thanks for any help,
Tom

I would think if it was full advance, the starter would hang up from the engine trying to fire the fuel before the piston was up.

Check valve in fuel pump not holding residual pressure after shutoff or pressure regulator is leaking too!

D-Jet, L-Jet, CIS, etc must hold pressure for a period of time after a hot shutdown to start readily. Usually 15 - 20 psi for about 20 mins depending upon system.

Thanks Slits, I'll check that out.
Tom

why are you pressing on the gas pedal "padal to the floor?" when starting? I have a 74 djet and never press on the pedal for starts. Maybe I didn't understand you correctly.

Read somewhere in another thread about that helping sometimes. First time I had the problem, it wouldn't fire, so I pressed the pedal to the floor and sure enough it fired after about 10-15 seconds of cranking. ??? Don't understand why, but it has worked for me several times.
Thought of something lese to try this weekend to narrow the problem down. I'll take a small can of carb cleaner with me. If the problem shows up, I'll spray a little in the intake mouth of the cleaner. If it starts, then it must be fuel related. Make sense to you guys?
Tom

Pedal to the floor is normaly "flood clear" mode. No injectors firing. At least thats what i've been told.

That did cross my mind also, but when it finally starts, no dark smoke like a flooded engine usually shows. And why would it flood? It has been sitting for 10-15 minutes not running? Leaking injectors?
Tom

The fuel boils on the supply side (lines & pump) on a '69 - '74 due to where the pump is located (vapor lock). The pump will get really hot and it sucks at pumping air, bubbles or fumes.

In '75-'76 they moved the pump to the front under the tank to alleviate this problem.

That is why I mentioned leaks (yours is a '76) ... I have fought the problem on a couple of vehicles. Once I could get it to hold pressure in the system after a hot shutdown, it would start right up hot.

But then I'm just a barbaric backyard shadetree mechanic.

OK, put the pressure gage on and it holds 25 psi for 30 min. Still has the " hard starting problem after warmed up and sitting for 10 min". Once it restarts after being "hard to start after warm", and you turn it off and try to restart it right away, it starts right back up. The hard to start only happens after sitting for a short time. If it sits for an hour or more there is no starting problem.
Any thing I should check next? The car runs so good otherwise, Im just stumped as to what could cause this, It isn't leaking injectors , I've pulled the plugs after cranking and not firing and they are not soaked.
Thanks,
Tom

Change the coil. It might e getting heat soaked.

Start with the basics. 90% of fuel related problems are electrical. I would start with checking the points and condensor. They could be fried. Definately the coil as suggested. could just be weak spark from a cracked cap. try it at night and look for leaking spark.

CHTS going bad or wire brittle/grounding?

News flash, guys. THEY DID THIS WHEN THEY WERE NEW!

The Cap'n

OK Cap'n. I was sure I had heard of this years before. Is there any fix? Car has about 1500 miles on a complete tune up with points, plugs, cap, rotor. wires, etc. Had the engine out to replace seals and clean it up and went through all of the FI harness and engine wiring and replaced connectors and wires that did not look or read good with an ohmmeter' Checked all of the ground connections and wire brushed and renewed as needed. As in earlier post, runs just great otherwise.
Thanks,
Tom

Anyone have any more ideas to fix this or have any of you had this type of problem?
I think the next time I'm out driving, I'll park on a hill and see if it shows up to be hard starting after sitting for 10-15 min. Then I can let it bump start and see if that makes a difference. The starter is turning over very well- not slow at all. Have an Optima 34R and it is in great condition, so I really don't think it is a low voltage problem.
Thanks,
Tom

I had a simular problem with my 1st 914. Thinking back it was definetly an electrical issue. I believe it was the ignition switch that was the culprit. Only happened after the car was warm.

My 74 2.0 did that and it was the contacts in the ignition switch....heat=more resistance, perhaps that's why it's shows its ugly head when warm.

I also agree with checking the coil...have you, or swap it out.

My bet is on electrical.

I have exactly the same problem, and am following this thread hoping to get some new ideas. My ignition switch is new.

I've been suspecting that the spark is somehow not hot enough. Swapping out the coil (which isn't that old) may be my next step.

Cold start valve sticking open?

Thanks for the replys.
Don't think the ignition switch is bad. The hard to stsrt issue comes into play after sitting for 10-15 minutes. Since the switch is in the passenger comp, it should cool rather quicky. I am using logical trouble shooting methods here and maybe that is part of the problem. I rebuilt the ignition harness using new teflon coated wire and all new connectors, so I'm pretty sure that isn't the problem. I guess the next step is to take some voltage readings while starting cold and then more when the hard to start problem is there and compare the readings. I'll post the findings when I have them.
Not the cold start valve as I have the pressure gage hooked up there now.
I'm surprised that this doesn't have a more widely known cure since it has been around since the cars were new?
Tom

As the Cap'n says, this is "normal" behavior. Mine does the same thing, though not as bad as described here. It's a flaw in the system design. The head cools off more rapidly than the rest of the engine, so the head temp sensor gets "cold" even after only 10 minutes. However, the core of the engine is still quite hot. The net result is you get too rich a mixture and it makes starting hard, and the first few minutes of running are too rich until the heads heat back up. If you let it sit for a full hour, the whole engine gets cold and that's why it starts fine. Mystery solved.

One way to start it more effectively is to open the throttle completely BEFORE turning the key. If you open the throttle once you turn the key, you pump 20 ms worth of gas into two of the cylinders due to the action of the throttle switch, making it even richer. Try that next time and see if it starts faster.

Thanks for the answer Brad. The times I had this happen, I got it to start by fully opening the throttle. Next time I.ll try fully open before trying to start.
Tom

Since it happens warm, have you tried to check the resistance of the temp sensor? I believe it is supposed to be 20000 ohms when cold and under 300 ohms at operating temp. If the temp sensor is ok and the FI is working as designed then the engine is not getting a rich fuel mix on startup as it does when it is cold. Have you checked your vacuum lines? A vacuum leak could leave you with a too lean mixture. Of course, it should also leave you with a high idle which you are NOT getting.

Do you have a vacuum gauge?

You wrote that you do not get black smoke when it does start, maybe it is too lean.
You also wrote "I've pulled the plugs after cranking and not firing and they are not soaked. " Are the plugs at least a little wet?

Hope this is of some help.

The CHT is about 3K ohms when at 70 deg. F, and under 50 ohms at operating temperature. See my comments above, the issue is that the heads cool off much more quickly than the cast iron cylinders and pistons, leading to rich starting mixtures after 10-15 min of sitting. You know it's rich because you can get it to start by giving it more air (i.e. opening the throttle). BTW, in D-Jet, vacuum leaks in the intake system do not lead to lean running, as it's a speed-density system. AFM systems (e.g. L-Jet) go lean under vacuum leaks. The lack of black smoke is because when this problem happens, the engine isn't flooded, simply getting too rich a mixture.

Brad,s answer makes perfect sense to me. As soon as it warms up some here in the PNW, I''l put this to the test and let you all know what the results are.
Tom

Tom,

Any resolution on your issue? I've had the Exact same issue on my '75 2.0 and have been in the habit of holding the pedal to the floor to get it to start. I understand the theory about the heads cooling faster, but the car didn't seem to have this problem many years ago.

I have a new CHT sensor and it didn't seem to help.

Tim

Well, it is a year later and I only had this happen once this summer, but I haven't been driving the car much as my back has been giving me grief. I used the "pedal down before starting" the one time it didn't want to fire and it started much faster. I usually just have to turn the key to start with no throttle applied to get this car to start up and then it idles OK. When this doesn't get the car to start, I turn the key to off, press pedal to the floor, then try starting again. Started up in less than 10 seconds.
Tom

Can the resistance from the CHT be lowered to correct for the temperature differences ?

I experienced almost the similar symptoms this summer in my 74 2.0L, although my car actually stalled and then wouldn't start. Car has always started and idled strongly when cold. I've been told it's vapor lock, and I've been told vapor lock is a myth (Fuel pump is in the stock position for a 74). I don't care what it is, but I'd sure love to be able to trust my car again. I did look in my gas tank and found some rust at the bottom but it didn't look like enough to clog the fuel screen or a fuel filter. Here's what my experience was (this all happened on one day):

1) Drove about 15 miles then parked the car for 1.5 hours. Car wouldn't start. Tried intermittently for 10-15 minutes until I finally held down the pedal for 30-45 seconds (at least) and the car finally started.

2) Drove about 3 miles to the store and parked the car for 5-10 minutes. Car wouldn't start. Tried intermittently for 15-20 minutes until I finally held down the pedal for 30-45 seconds (at least) and the car finally started.

3) Drove about 15 miles and the car stalled on the highway. I was downshifting from 4th to 3rd when the car stalled (slow traffic + going up a hill). Car wouldn't start. Tried intermittently for 20-30 minutes until I finally held down the pedal for 30-45 seconds (at least) and the car finally started.

4) Drove another mile and the car stalled down the street from my house. I was downshifting from 3rd to 2nd (turning onto my street). Car wouldn't start. Left it parked for a few hours and then it started right up.

1972 FI
Heres my story:

Starts fine cold. After warmed up, won't start, seems flooded. More so hot weather.

To start, I pull the pump relay and crank it over two times. Each time it will start and run 2 to 5 sec, with out the relay plugged in!. I think this is clearing out the fuel.

Plug in the relay, crank and depress the pedal slightly right after turning the key....fires right up! If not replete, sometimes 3-4 times.

This only happens on hot soak. This has gotten much worst. Every time I drive the car I must now do this for it to start. Unless restarting within 1 to 3 min.

Never had this concern for years, then all of a sudden. Swapped out many items, no solution. HELP please if you can.

Thanks