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Cranks, no start


charliekwin

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Pretty sure it's the ground for the ignition module.  They even show the little eyelet.  From that point the path from the engine to the battery negative and alternator body needs to be good.  A resistive ground circuit will cause weak spark.  Always a good idea to measure ground circuit resistance when troubleshooting.  It's commonly overlooked.  

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

The other EFI bible checks were good, but that doesn't mean the ECU isn't bad

Can't remember if we talked about Pin 1 and the blue wire.  No blue wire pulse, no injection.

The first EFI book, 1975, even talks about pulling the ignition coil power wire several times, with the key on, and listening for the injectors on every third disconnection.  I don't know if the later book describes that.  It's a simple test of the Pin 1 blue/wire circuit and ECU function.  No whirring starter motors to try to hear over.

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Should be, right?! No new update yet. It's been raining here in Los Angeles and that's kept me from looking for the fuel pump leak but the weather finally cleared up last night. 

The ground wire that Zed marked is connected as well, but Pin 1 and the blue wire I hadn't heard about before. That''ll be on the list after fixing the pump. 

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3 hours ago, charliekwin said:

The ground wire that Zed marked is connected as well

You should still measure resistance back to the battery, at least.  I have a flashlight that only works if I unscrew the base slightly.  It looks like it should have a nice solid ground but the bulb won't light until I loosen the cap on the bottom.  Ironic.

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Well since this all started when you messed with the AAR, the logical conclusion is that the AAR work is related somehow. Of course, there's always the possibility of a completely spontaneous unrelated failure, but let's just mess with the idea of the AAR being involved somehow. I don't know what's going on, but I'm just gonna poke around a little.

At the beginning of the thread, you said you took the AAR off. What exactly did you do? You detached the electrical connector off the AAR and then what? I assume you loosened a couple hose clamps and took out the bolts that hold the AAR to the intake manifold and pulled the AAR off the manifold.

Did you cap the connections that used to go to the AAR (right way)? Or did you put in a piece of tube to connect the two ends where the AAR used to be (not the right way)?

Did you take off any other electrical connectors as part of the job? Cold start? Throttle position sensor?

At the beginning of the thread, you said you had spark. Are you sure?

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Here's a picture of the engine as it sits right now. I have the AAR heater plate there just for the vacuum line at the BPT, but removing it doesn't make a difference. Connecting or disconnecting the electrical connector for the AAR doesn't matter either. Last time it ran was Friday two weeks ago; other than having the coolant lines still connected to the heater plate, it was set up like this.

20190207_171012.jpg

FWIW, here's my AAR. It doesn't move. I've never had a fast idle since I bought the car, but the weather we have here in SoCal hasn't made that an issue.

20190207_171159.jpg

I also took a quick video before the pump leak appeared. Here is the car trying to turn over. If I let it sit for a day or two with the plugs removed, the first time cranking, it'll do this. Then nothing. It's done this fire-once-after-sitting-without-plugs-for-a-day thing three times, which at least is repeatable. Busy week, but hopefully should have some time Friday to get to the leak.

 

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As expected, I don't see an obvious smoking gun, but here's a couple things to think about and/or look into.

First, all that TVV thing does is block the vacuum to the EGR system until the engine warms up. It should be a closed valve until the engine warms up and this disables the entire EGR system. 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.

And as a caveat (1a) to the above... The vacuum source for the EGR system comes off a ported source from the throttle body that presents no vacuum at idle anyway, so that whole thing shouldn't be doing anything at all unless your foot is on the pedal. It's similar to the distributor advance vacuum... Nothing at idle, nothing at WOT, but highest at light cruise position.

Second, the simplest suggestion would be to try pushing down on the gas pedal a little bit while you try to start the car. Your AAR looks to be open a significant amount and once you took that off the car and blocked the holes, you have removed that amount of idle boost. Your car may simply be completely clamped shut now and can't get enough air to even idle. Try holding the pedal down a little and see if it'll run.

Third, I see the rubber stopper in the intake duct for one side of where the AAR used to connect, but  I'm not sure what you did with the other side over on the throttle body top. Looks like aluminum foil or something? The point is... The AAR connection side coming off the throttle body is the high vacuum side and needs to be sealed very well. Even more important than the side coming off the intake duct. They're both important, but because of the high vacuum on the intake manifold side, that side needs to be even better.

Fourth... All that wiring going to your potentiometer and the water temperature sensors in the thermostat housing? Ewwww.   LOL

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