Fuel Issue - Hard To Start

[LordFly]

Now that I'm driving the car frequently, this is starting to get annoying: When the car is cold, pump the gas twice, turn the key, she starts perfectly fine. Not sure why you need to pump it twice, but that's what the PO told me, and I didn't follow those instructions a few times and it took forever after that to get it going. The annoying part is that when the car is warmed up, restarting is a gigantic PITA! I have not found a consistent technique to start it when warm. Holding the gas, pumping the gas (before or during), no gas, floored, etc., all fail. The only thing that seems to start it when warm is cranking it for about 10-15 seconds (doing whatever you feel like with the gas), letting it sit for 10 - 15 seconds, then cranking again for 10-15 seconds and she'll finally come to life. I joke that "it starts just like in the movie", but it's getting a little embarrassing, and hitting my head on the steering wheel doesn't start it either :blackeye: I know very very little about the whole K-jet system at this point. I get the very basic concept, but couldn't troubleshoot it to save my life. This seems like a good one to start with, so if someone could point me in the right direction, that would be fantastic :)

[jawn101]

You'll definitely just want to search the forum for hot start threads. Every possible thing has been covered - read them over and see what you find first.

As for the difficulty to start when cold, you shouldn't have to pump the gas... When you turn the key on (second click, before starting) does the pump prime?

[LordFly]

When you turn the key on (second click, before starting) does the pump prime?

Certainly sounds like it does.

[jawn101]

OK. There's just so many things to check, then that I barely even know where to begin. :)

- Rest pressure. After the car has been running a while, turn the motor off and remove the air cleaner. After about an hour, try to gently press down the air metering plate. Is there resistance or does it just bounce around? This will help identify possible issues with the accumulator and is a good starting point for identifying hot start issues.

- Plug swap. If you have trouble starting cold, swap the grey plug from the WUR onto the blue socket on the CSV, then try to crank the engine. Whether or not it fires right up, be sure to remove the grey plug immediately after cranking or you will flood the engine. This applies constant voltage to the CSV and injects fuel whether or not the CSV circuit is actually working and can point to issues with the thermotime switch or the ancillary wiring. This is a good starting point for identifying cold start issues.

There are really tons of threads on both cold and hot start issues though, with lots of info from people much more experienced than I.

[Bitsyncmaster]

Does it take time sitting after the engine is hot to show up the problem? Or does it show up with a restart right after you shut the engine off?

[LordFly]

Does it take time sitting after the engine is hot to show up the problem? Or does it show up with a restart right after you shut the engine off?

Hmm, never tried that. I'll do it in about half an hour when I get to work. It doesn't seem to be a problem if it's only partly warmed up. If I only drive for a couple of minutes, it usually starts back up just fine.

[LordFly]

It's a rain day, going to have to hold off on that test until either this evening or tomorrow. Gives me time read other threads :wink:

[David T]

I would start with trying to get the car to start better when cold. Verify that the cold start valve is operating during cranking when cold. Pumping the gas pedal does absolutely nothing on a fuel injected car. The recommended procedure is to hold the pedal down partway when starting but most Deloreans will start fine without touching the pedal at all.
David Teitelbaum

[LordFly]

Pumping the gas pedal does absolutely nothing on a fuel injected car.

I absolutely agree, especially with the key off. Which is why I tired it a couple of times without pumping it first... had to get it boosted once because I had to crank it so long the battery died. But for whatever reason: 2 pumps, turn key, purr like kitten.

[jawn101]

I absolutely agree, especially with the key off. Which is why I tired it a couple of times without pumping it first... had to get it boosted once because I had to crank it so long the battery died. But for whatever reason: 2 pumps, turn key, purr like kitten.

I've noticed on my car (though I have the solid state RPM relay) if I have the key on and hit the gas to disengage the idle microswitch a few times, the pump will prime again. Does that happen in your car as well? Perhaps you have a pressure issue.

Check rest pressure. Test the CSV. Let us know.

[Bitsyncmaster]

I've noticed on my car (though I have the solid state RPM relay) if I have the key on and hit the gas to disengage the idle microswitch a few times, the pump will prime again. Does that happen in your car as well? Perhaps you have a pressure issue.

Check rest pressure. Test the CSV. Let us know.

What causes that extra prime is the noise created when the vacuum solenoid turns on and off. The capacitor on some cars seems to stop that noise (that cap is on the engine near the idle switch). But it's not a problem if the RPM relay gets the extra pulse

[OverlandMan]

My hot start issues were resolved by replacing the fuel accumulator. $150 kit from DMCH. It's a Bosch part if I recall. PITA to change out if you don't have a lift.

My symptoms were very similar to yours.

[David T]

A bad accumulator would account for the hard hot restart, not the hard cold start. He may very well have a bad accumulator but he has to get it to start easily cold first.
David Teitelbaum

[OverlandMan]

A bad accumulator would account for the hard hot restart, not the hard cold start. He may very well have a bad accumulator but he has to get it to start easily cold first.
David Teitelbaum

That's fine... just thought I'd share since he has a hot start issue as well.