No Start After Doing Basic Maintenance

[kings1527]

Hi all,

Strange thing going on. After doing a VOD teardown and replacing plugs, wires, cap, rotor, and fuel injectors (all OEM stuff....Bosch, Bougicord, etc), I can't get it to start. I did a plug swap with the CSV and it'll start that way but not with everything plugged in where it should be. Looks like I've isolated it to fuel. Everything was working 100% prior to this job.

I'll also jump the RPM relay and confirm the pump is running, which is does (new integrated pump/sender) but it won't start with the RPM relay jumped. Prior to plug swap, I pulled a spark plug and confirmed spark. Tapped the distributor a few times with a dead blow mallet just in case the plunger got stuck but the car was only apart for a day.

Wondering if the new fuel injectors won't crack open? Is there a chance fuel injectors weren't a direct replacement and a different spec as to when they crack?

When I was jumping the RPM relay, one of the spades came into contact with a different terminal on the plug for a brief second. Could I have killed something that way? Trying to think of everything here.

What say you?

[DMC5180]

Sounds like the CSV circuit is suspect. Have you verified the TTS is plugged in and the grounds are all attached at the intake manifold near the ISM mounting bracket?

Btw, you didn’t mention if, once you get it started with the plug, does it stay running at normal idle once the Plug is removed from the CSV?


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[kings1527]

Sounds like the CSV circuit is suspect. Have you verified the TTS is plugged in and the grounds are all attached at the intake manifold near the ISM mounting bracket?

Btw, you didn’t mention if, once you get it started with the plug, does it stay running at normal idle once the Plug is removed from the CSV?


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Grounds are attached to the manifold by the ISM. I’ll double check the connection at the TTS.

I’ll troubleshoot the plug swap that you mentioned in about 30min.

Even if I’m forcing the pump to run by jumping the RPM relay, shouldn’t that cause everything to run by forcing fuel through the system?

[dn010]

Make sure you didn't bump the resistor connectors or that they're corroded.

[DMC5180]

It forces fuel to circulate from the pump to the FD back to the tank. You still need the air flap to move down enough to crack the plunger and flow fuel to the injectors.


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[Bitsyncmaster]

After all that work and new parts I bet you just need to adjust the mixture.

[DMC5180]

Make sure you didn't bump the resistor connectors or that they're corroded.

If he got the engine to run, it’s probably not the Resistor connections, but always good to verify anyway.


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[DMC5180]

After all that work and new parts I bet you just need to adjust the mixture.

Certainly possible, but it still should fire via the CSV fuel during cranking.


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[kings1527]

Oh boy. So....if I can ask everyone to put down the over-ripened tomatoes so they can't be thrown in my direction. But problem solved.

I was doing the plug swap again to check on Dennis' idea and when I did it and started the car, I was hearing a huge hiss that was an obvious vacuum leak. Turns out, the rubber elbow connecting the ISM to the pipe of agony had backed off and disconnected itself somehow. I connected that and after cranking for a bit, everything fired up and is running good.

Even though it did take 30-60 sec worth of cranking before it fired and ran, I surmised that that was due to all of my fuel lines being completely empty from installing all new injectors. Once they primed during the cranking process, all was well.

So, with the vacuum leak, I'm guessing this is what was happening?

1) The lack of vacuum in the mixture control unit effectively makes a higher pressure inside the control unit.
2) This higher pressure prevents the meter plate from being able to drop, which
3) Means that the plunger can't move and let fuel flow into the fuel lines and ultimately the injectors

Is all that right?


And again, thanks a bunch for the quick help. Sorry...I'm better than what I did today! :)




After all that work and new parts I bet you just need to adjust the mixture.

Definitely next on the list. Thanks Dave.

[DMC5180]

1,2,3 is a perfectly logical explanation.

congrats on the quick fix. Stuff happens [emoji6].

I inadvertently knocked the coil wire off the distributor cap while doing other stuff once. That was head scratcher initially, but was found quickly.


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[kings1527]

1,2,3 is a perfectly logical explanation.

congrats on the quick fix. Stuff happens [emoji6].

I inadvertently knocked the coil wire off the distributor cap while doing other stuff once. That was head scratcher initially, but was found quickly.


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Thanks again, Dennis! Hope you're well.

[DMC5180]

Thanks again, Dennis! Hope you're well.

I’m doing great, thanks [emoji106]

Happy new year [emoji324]


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[David T]

The large vacuum leak leaned the mixture out so much it would only run if you over-enrichened the fuel mixture with the CSV. When air leaks into the induction system after the metering unit it is called "False Air". Because it is not measured and accounted for the additional fuel is not metered in to it. Luckily it was a simple fix. Since you found that you should reexamine everything again just to make sure it is all proper. Then congratulate yourself for a big job well done.