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charliekwin

Cranks, no start

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1 hour ago, Captain Obvious said:

You can "manually" disable the entire EFR system by pulling the tube off the underside of the throttle body and capping it. This won't work for you when inspection time rolls around, but just for troubleshooting this current problem, it would be easier if that thing wasn't hanging off the engine.

I did away with all that stuff on my '77.  Here's a picture of the plugged throttle body.

image.png

 

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Well, I think I have a good lead here.

The source of my fuel pump leak...that was obvious. The other houses around the pump and damper look good, but the are some that I haven't replaced and will do the rest of them soon enough.

Anyway, when I fixed the pump, the same one-fire situation happened again. It really seems fuel related, so I pulled off the fuel rail to check the injectors. I've wanted to do this eventually, so this just forced the issue a bit.

Anyway, a couple of cranks later, I got this much fuel in each of the cups for the cylinders.

And I got this much from the cold start valve.20190208_151757.jpeg20190208_170015.jpeg20190208_170024.jpeg

Sent from my SM-G950U1 using Tapatalk

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On 2/1/2019 at 6:05 PM, charliekwin said:

Used real starting fluid, didn't get even a pop out of it. 

The facts are getting kind of random and don't fit well.  Your video showed that it l almost started, more than just a pop, it sounded like a short series of ignitions, on just gasoline.  But you said you didn't even get a pop before with a much more potent fuel, so the focus was on spark.  Now you're measuring output at the injectors but they really don't squirt much at low RPM.  Not clear if what's in the cup is a lot or a little.

You're kind of at the point where it might pay to just write down what you know and put a methodical plan of action together.

Many people get to this point via different ways.  A bunch of disconnected observations that don't really show a solution.  No offense, it happens to many.

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If that's a lot of fuel for the amount of time cranking, and your temperature sensor reading at the ECU is in range, then bad ECU comes to mind.  Disconnecting all of the injectors might get it to run for a few seconds.  It might be flooding due to the ECU keeping the injectors open.

Just one thought, for the action plan.

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Here's what the CSV is doing:

Won't open/fire if the connector is disconnected, so it's not stuck open. I can at least try putting it back together and leaving the CSV disconnected to see what happens, then try to track down the cause.

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7 minutes ago, Zed Head said:

The facts are getting kind of random and don't fit well.  Your video showed that it l almost started, more than just a pop, it sounded like a short series of ignitions, on just gasoline.  But you said you didn't even get a pop before with a much more potent fuel, so the focus was on spark.  Now you're measuring output at the injectors but they really don't squirt much at low RPM.  Not clear if what's in the cup is a lot or a little.

You're kind of at the point where it might pay to just write down what you know and put a methodical plan of action together.

Many people get to this point via different ways.  A bunch of disconnected observations that don't really show a solution.  No offense, it happens to many.

There's some overlapping timelines in the posts. I tried starting fluid early on and it never fired with that. The almost-starts happened later on. With the amount of fuel in there, it's no surprise starting fluid didn't help.

And the cups from the cylinder injectors had maybe 1/4tsp of fuel. The CSV spit out a tablespoon or two. Now to figure out why...

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I might do both, plus one.  Disconnect the injectors and it will probably start and run for a few seconds on CSV fuel.  Disconnect the CSV and see what happens with the injectors connected.  Disconnect them both and start it on starting fluid.

By the end you'll probably be certain about spark.

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5 minutes ago, charliekwin said:

And the cups from the cylinder injectors had maybe 1/4tsp of fuel. The CSV spit out a tablespoon or two. Now to figure out why...

Figure out why about what? Why the cold start put out a lot more fuel than the individual cylinder injectors? Because it's designed that way. Seems completely normal to me.

I still think the obvious explanation is that you are flooding your engine by trying to start an engine that was working properly when there was a significant bypass around the throttle plate (the AAR). You removed that bypass and didn't add extra air from somewhere else, but you kept the fuel the same.

Did you try holding the gas pedal down a little bit while you cranked the engine? That might not be it, but it's so simple to try!

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I tried searching for CSV videos and found nothing, so was just making assumptions about the CSV based on the other injectors. It seems like a lot of fuel to me, but that's just me guessing. And you know what they say about assumptions. I have tried holding the gas down a bit while cranking, but I think it's flooding before it can start. With your and Zed's help, I have a game plan for tomorrow.

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Well I don't have any hard numbers for you, but IMHO that cold start valve looks perfect.

I took a quick look through the FSM to see if I could find some real numbers and came up empty. There may be some flow measurement numbers in there somewhere for the CSV, but with a quick review, I didn't find any.

Only thing I DID find was in the FI manual... On page 16 where they are describing the operation of the CSV, they say "the fuel injected Z-car needs a choke system which supplies very large amounts of fuel only during starting."

So the factory expected amount of fuel is "very large". I think you nailed it.  LOL

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Try this... Make sure your battery is up to top charge (after all the fruitless cranking) and disconnect the connector to the CSV (which will disable the CSV).

Then hold your foot on the pedal "a little bit" (like where your foot would be when you are cruising on a flat level road) and then crank it to see if it will start. Now, don't expect instant operation... I removed my CSV a while ago and I can definitely tell that it takes longer to start without it. Not enough to make me want to put it back on, but definitely longer.

Might take me five to ten seconds of cranking to get it to fire if the temp is 40 or lower? Doesn't sound like a lot of cranking when you read it like that, but count "one-one thousand, two-one thousand, etc" for six seconds and picture yourself holding the key while you do that. It's a significant amount of time and longer than what you've been doing in your videos.

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1 hour ago, Captain Obvious said:

I still think the obvious explanation is that you are flooding your engine by trying to start an engine that was working properly when there was a significant bypass around the throttle plate (the AAR). You removed that bypass and didn't add extra air from somewhere else, but you kept the fuel the same.

This does make the most sense.  I feel bad for getting distracted with the other stuff.

The assumption was that you removed a functioning AAR but if your AAR was stuck in that position, never fully closing like it's supposed to then the idle adjustment bypass would have been adjusted down to almost closed to make up for the AAR opening.  When it was removed you're left with no air with the throttle closed..

If you want to take CO's suggestion one step further just open up your idle speed screw, the screw with the big head and a spring under it.  Turn it counterclockwise a few turns.  Then you'll still be on the idle circuit of the TVS, but with more air.  You'll need to do that anyway, probably.  Hope that's it.  Now you are an EFI expert.

image.png

Edited by Zed Head

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1 hour ago, Captain Obvious said:

I still think the obvious explanation is that you are flooding your engine by trying to start an engine that was working properly when there was a significant bypass around the throttle plate (the AAR).

It might not even really be flooding, explaining the dry plugs.  It's more of a choking.  No air flow in to the cylinders to pull the CSV fuel.  Also explains the gas smell, the intake manifold is loaded up with CSV gasoline that never moved.

Edited by Zed Head

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I don't know if you guys are Simpsons fans, but there's an episode where a doctor tells Mr. Burns he's alive because all of his ailments are fighting each other and staying in balance. I think back on things done by POs that I've fixed in the past (throttle position switch, missing thermostat, bad coolant temp sensor) and it reminds me of that scene.

Sent from my SM-G950U1 using Tapatalk

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Well don't get all hopeful yet guys. It's just a theory. The simple (the Obvious) one to look into. Hopefully it's that easy, but it's still a potentially failed avenue.

However, in the end of all this, I do hope you completely clean up all the wiring going to the sensors in the throttle body. Clean, shiny, well packaged.

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10 hours ago, charliekwin said:

doctor tells Mr. Burns he's alive because all of his ailments are fighting each other and staying in balance.

Pretty much every Z I've messed with is in this category. AFM's adjusted to account for vacuum leaks. Idle speeds adjusted to account for BCDD leaks. Etc...

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Car runs!

I put the rail back on, opened up the idle screw one full turn and it fired right up.

Tried to turn it back a bit and it died. Looks like it had been turned in too far to compensate for the stuck AAR.

Air, fuel, spark. In retrospect, I got too hung up on it running once after removing the AAR. And took for granted that it was getting air.

On the plus side, I saved a trip on a tow truck with the burst hose. And it's idling better, so I'm ahead of where I was at the beginning. That's what got this started to begin with.

And yes Capt, that mess of wiring has been on my to-do list since forever. It keeps working and passing smog, so it never moves up.

Many thanks to all for their help.

Sent from my SM-G950U1 using Tapatalk

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17 hours ago, charliekwin said:

Car runs! I put the rail back on, opened up the idle screw one full turn and it fired right up.

Awesome! My kind of problem!! A non-problem!

So either it was just the wiener in the warp drive from taking off the AAR and starving the engine for air, or there's an electrical intermittent connection in your wiring tangles. You'll find out at the most in-opportune time.  LOL

But even if it isn't keeping you from passing smog, you might want to take some time off from other projects on the car and clean that stuff up. I've found a great sense of peace knowing that all my EFI connections are new, clean, and tight.

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