78 280z flooding when starting

[siteunseen]

It's like a treasure hunt.  Sounds like you are getting close.  Let us know when you find it, maybe we all can learn something for the future. 8^)

[Zed Head]

2 hours ago, Dogariffic said:

After stopping she would turn over but no spark.

You have the correlation or cause-effect conundrum.  The loose wire might have been significant but not the cause of the problem.  Intermittent problems are the hardest to solve, you have to be ready to test and diagnose right when they happen.

When you say "spark" do you mean that you actually removed a plug wire and checked for spark?  Or that the engine wouldn't fire?  No spark could be the fairly common ignition module problem, no-fire could be wet plugs.

[Dogariffic]

When I say no spark what I mean is that the engine would turn over but it was not trying to catch.....like there was no fire.  At the time I did not remove the plugs to look at them. I foolishly did not have my tools with me.

[Dave WM]

15 minutes ago, Dogariffic said:

When I say no spark what I mean is that the engine would turn over but it was not trying to catch.....like there was no fire.  At the time I did not remove the plugs to look at them. I foolishly did not have my tools with me.

could be no fuel as well. Carry a spare plug with you, next time this happens disconnect the center wire from the distributer and attach to the spare plug, lay it on the strut tower screws and see if there is a spark while trying to start. You need to eliminate the variables when dealing with intermittent issues.

Edited June 23, 2017 by Dave WM

[Zed Head]

Oops.  Stepped on Dave's lines...

You can get spark testers also.  I've never tried one but they make sense.  Hard to see the spark sometimes if it's bright out.

Edited June 23, 2017 by Zed Head

[EuroDat]

Here is the leak test procedure I did on mine a couple of years back.

It's good to eliminate possible causes. I know you replaced a lot of items, but some of the parts these days are "remanufactured" items and the quality is sometimes lacking.

Btw: You can not remanufacture 280Z injectors. All you can do is change external stuff like the inlet filter and hose, and run them on a test unit with special cleaner. Not all aftermarket parts are new parts...

Instruction - Fuel Pressure Test 280Z RevB.pdf

[Dave WM]

video of check for spark

of course this only goes as far as the lead from the coil, does not check the function of the distributer to the plugs.

I have confirmed good battery voltage while under load of cranking (over 11v) and have gone thru all the normal stuff like cleaning all the connectors and grounds. Some times it just takes a little longer to start. This is NOT the hot restart issue. I am hoping this video helps you think thru the diagnosis of your issue.

Edited June 24, 2017 by Dave WM

[Dogariffic]

ok.

Beginning a few tests.

The goal is to determine my over fueling issues and the reason the Z has begun to simply cut off.

To catch you up.....I started the car yesterday and let it idle for about 15 minutes then pulled the plugs.  It hesitated ever so briefly before firing off and idling smoothly.  The plugs were dry but covered in black soot.  Not a surprise after the car cutting itself off the previous day.

I pulled the plugs cold this morning and there was no change.  No additional wetness etc.

I then started the car and again it briefly hesitated before firing off an idling smoothly.  I then checked the AMF and manipulated it a bit at idle and 3,000 RPM. It ran slightly better moving it only a mm or 2 clockwise at idle to lean it up.  Manipulating it counter clockwise made the engine run rough at idle.  I did not notice a difference at 3,000 RPM when manipulating it clockwise but it ran rough counterclockwise....... I have the glue on my AMF by the way.  It has never been adjusted.

I then decided to take my tools and take the car around the block.  She ran like a champ.  After 5 minutes I turned back toward the house ...not wanting to challenge the Z gods. About 100 yards from the driveway she cut off.  No heads up. No miss-fire. The Tach went to 0. I was able to coast back to the garage and immediately gave thanks I was not stuck on the freeway again.

I then pulled the plugs.   Photo attached.  If I had run it longer more of the soot would have burned off in my opinion, but the tip was hot and clean. So I am determining that I don't really have a fuel issue that is leading to flooding and the car simply cutting off.  

I will now move to searching for an electrical gremlin.

I believe I will begin with the ignition module buy will also check connections in the ECU.

Thoughts? 

 

 

Edited June 24, 2017 by Dogariffic

[Zed Head]

12 minutes ago, Dogariffic said:

she cut off.  No heads up. No miss-fire. The Tach went to 0.

Was the transmission still in gear and the engine still turning over while the tach was at zero?  Could be that you have an ignition module problem.

[Dogariffic]

2 hours ago, Dave WM said:

video of check for spark

of course this only goes as far as the lead from the coil, does not check the function of the distributer to the plugs.

I have confirmed good battery voltage while under load of cranking (over 11v) and have gone thru all the normal stuff like cleaning all the connectors and grounds. Some times it just takes a little longer to start. This is NOT the hot restart issue. I am hoping this video helps you think thru the diagnosis of your issue.

Thanks Dave.

I jumped on this just before doing the other tests I mentioned and saw no spark from that lead....

Edited to add...I do have spark. I did not have the lead close enough to the shock mount for it to jump....Edited again to add...I have spark sometimes and sometimes not...

Edited June 24, 2017 by Dogariffic

[Dogariffic]

2 minutes ago, Zed Head said:

Was the transmission still in gear and the engine still turning over while the tach was at zero?  Could be that you have an ignition module problem.

The transmission was in gear, but I put the clutch in so I could coast.....but the clutch was out and engaged in second gear when it popped off.

[EuroDat]

50 minutes ago, Dogariffic said:

I then started the car and again it briefly hesitated before firing off an idling smoothly.  I then checked the AMF and manipulated it a bit at idle and 3,000 RPM. It ran slightly better moving it only a mm or 2 clockwise at idle to lean it up.  Manipulating it counter clockwise made the engine run rough at idle.  I did not notice a difference at 3,000 RPM when manipulating it clockwise but it ran rough counterclockwise....... I have the glue on my AMF by the way.  It has never been adjusted.

I then decided to take my tools and take the car around the block.  She ran like a champ.  After 5 minutes I turned back toward the house ...not wanting to challenge the Z gods. About 100 yards from the driveway she cut off.  No heads up. No miss-fire. The Tach went to 0. I was able to coast back to the garage and immediately gave thanks I was not stuck on the freeway again.

I then pulled the plugs.   Photo attached.  If I had run it longer more of the soot would have burned off in my opinion, but the tip was hot and clean. So I am determining that I don't really have a fuel issue that is leading to flooding and the car simply cutting off.  

I will now move to searching for an electrical gremlin.

I believe I will begin with the ignition module buy will also check connections in the ECU.

Thoughts? 

If someone played with the adjustment of the AFM, you can calibrate it by using the coke can method. Here is a link to the Atlanticz website: http://atlanticz.ca/zclub/techtips/afm/calibration/index.html 

I had problems with my TIU and ended up changing it to a 4-pin HEI module. It use to work perfectly and once it warmed up, say after ten to twenty minutes, it would start playing up fierce and left my parked on the side of the road. I sprayed it with a can of contact cleaner to cool it down and the problem would go away for ten minutes or so.

This thread explains what I went through and it's also in the download section of this site.

Section 9 in the download file has some tests you can do. It wont find a problem that happens at random, unless it's happening while you are testing. Goodluck searching. 

Edited June 24, 2017 by EuroDat