Snw's OFFICIAL 280Z turbo build thread - SMPYWD!
Thread Starter
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Joined: Sep 2005
Posts: 9,532
From: lemont, Illinois
A bit more progress made. Probably go for the first start up tomorrow. Maybe... if not, mid next week.
All buttoned up
Old and new... That block may be used for a who cares project lets see how high I can raise the compression ratio on an L28 motor and what sort of beast N/A power it can make. That may be an E85 runner to avoid detonation
Empty space, looking for something to fill that void.
and a picture of beauty.
Leaving the tranny in just with a jack stand under it to keep it pointing slightly upward and lowering the engine into it was actually INCREDIBLY easy. Easier than any other tranny/engine mating I have ever done actually.
Stay tuned, more good stuff to come.
All buttoned up
Old and new... That block may be used for a who cares project lets see how high I can raise the compression ratio on an L28 motor and what sort of beast N/A power it can make. That may be an E85 runner to avoid detonation
Empty space, looking for something to fill that void.
and a picture of beauty.
Leaving the tranny in just with a jack stand under it to keep it pointing slightly upward and lowering the engine into it was actually INCREDIBLY easy. Easier than any other tranny/engine mating I have ever done actually.
Stay tuned, more good stuff to come.
Thread Starter
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Joined: Sep 2005
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From: lemont, Illinois
Done. Finished it Sunday. Started it right up n drove it around tge block in tge typical fresh motor fashion.
Only problem I'm having is the car only when driving, Not free reving, loosed spark. At least that's my thoughts, because it just starts to randomly stall out bad and the tach jumps all over the place which to me signifies spark signal to the coil is being lost. Grrrrr.... No idea what could be causing this. Good news is though it no longer smokes. Any input?
Only problem I'm having is the car only when driving, Not free reving, loosed spark. At least that's my thoughts, because it just starts to randomly stall out bad and the tach jumps all over the place which to me signifies spark signal to the coil is being lost. Grrrrr.... No idea what could be causing this. Good news is though it no longer smokes. Any input?
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
If the coil loses power, the tach should drop to zero even if the engine is turning and in gear. If it jumps then I'm not sure what that means.
I guess you can just double-check all the power and ground at the coil.
Did you mess with the distributor or crank angle sensor at all or is it all stock?
I guess you can just double-check all the power and ground at the coil.
Did you mess with the distributor or crank angle sensor at all or is it all stock?
Thread Starter
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Joined: Sep 2005
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From: lemont, Illinois
All stock n it only jumps when accelerating when it losses power tge tach drops rapidly. Sorry for poor wording. Jeff wasn't all this stuff from you? You ever run the stuff? N would to large of gauge wire between the ecu n coil on one prong cause any issues?
I have a present for you...
Joined: Mar 2003
Posts: 1,699
From: dayton, nevada usa
Not 100% sure on this but the early tach used the positive pulse from the coil and there is a resistor in the dash to it. The part I'm not sure about is the S130 cars use a neg? pulse from the ecu. I don't think this is related to stalling but the tach won't work if I'm right.
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Joined: May 2010
Posts: 114
From: Orlando, FL
Yep all that came out of a running car that ran great.
U have access to the ECU when driving? I had a 280zxt that when u wiggle the wires on the ECU itself it came alive. It almost acted as if it wasn't running on all cylinders.
Try cleaning the ECU connectors.
U have access to the ECU when driving? I had a 280zxt that when u wiggle the wires on the ECU itself it came alive. It almost acted as if it wasn't running on all cylinders.
Try cleaning the ECU connectors.
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
Originally Posted by Datsun Z Garage
280Z/ZXTACH "JUMPS" OCCASIONALLY
I thought this was the coil but I think I found the real cause. Note that the only thing that makes the tach needle move at all is a pulse to the tach sensor wire. 280 tach sensors are connected directly to the negative terminal on the coil. So for the tach to jump, something has to be affecting this pulse.
On day my voltage regulator starting acting up and began putting out spikes of 17-19 volts. And when my voltage needle jumped, so did the tach. That's when I realized that any excess voltage in the tach sensor wire causes it to jump. I suspect these "jolts" you see are the regulator hiccupping if you have a 240Z. If you have a 280Z then it's likely the alternator which has the regulator built in
I thought this was the coil but I think I found the real cause. Note that the only thing that makes the tach needle move at all is a pulse to the tach sensor wire. 280 tach sensors are connected directly to the negative terminal on the coil. So for the tach to jump, something has to be affecting this pulse.
On day my voltage regulator starting acting up and began putting out spikes of 17-19 volts. And when my voltage needle jumped, so did the tach. That's when I realized that any excess voltage in the tach sensor wire causes it to jump. I suspect these "jolts" you see are the regulator hiccupping if you have a 240Z. If you have a 280Z then it's likely the alternator which has the regulator built in
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From: lemont, Illinois
I also remember one day having a hard time starting the car. The starter was acting up. It's a weird issue. After many attempts I noticed a little smoke cone from the ecu. I'll check the other stuff first. N yes the ecu is right by my feet. My 260z had the wiggle the ecu connections issue.
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I'd like you all to watch this video i took, change the view to 720p so you can see the fuel pressure gauge better. While idling that needle is just under 30psi on the gauge. soooooo, think we found the problem?
http://www.youtube.com/watch?v=RySnj...4aSBqQg4ir9Sko
and go full screen. that marking just above the needle is the 30psi mark. watch all 5 minutes of it so you can really gauge how bad this issue is.
http://www.youtube.com/watch?v=RySnj...4aSBqQg4ir9Sko
and go full screen. that marking just above the needle is the 30psi mark. watch all 5 minutes of it so you can really gauge how bad this issue is.
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here is the internal view i recorded at the same time as the above video.
http://www.youtube.com/watch?v=BLeZO...ature=youtu.be
http://www.youtube.com/watch?v=BLeZO...ature=youtu.be
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From: lemont, Illinois
changed the FPR still seems to be doing the same. sitting at 28psi and dropping during revs. also that mark is 40psi above the needle my bad, but is still idling under 30psi and if it ever raises its briefly and it never passes 35ish psi
Registered User
Joined: Dec 2011
Posts: 45
From: Puerto Rico
Timing on MARK?Checked all wiring connections? How about those pump relays? Not back firing right?Could be electrical... Get some multiple coils.Bigger injectors maybe...what fuel pump your using?Could be a number of things.On mine something similar happens...the cut off and it`s usually my fuel pump relay.Hope you find the problem.
Last edited by BOOSTINMYZ; Dec 28, 2011 at 06:23 PM.
Thread Starter
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From: lemont, Illinois
Highly doubt its electrical. maybe bad fuel pump even though its new. unplugged the fpr from the vaccination source and got a jump in pressure to 36 Psi. so Idk. thinking that might be the issue. fuel pump is running fine though so not suspecting the relay. any other opinions.
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Joined: May 2010
Posts: 114
From: Orlando, FL
Was it any better with the base pressure at 36? What is strange is the need really jumps. I have the same gauge on my stock NA 78 and it doesn't move like that when you rev it?
How is the tank and lines? Did you ever drop the tank and clean it out?
Take an extra fuel pump and from a gallon of gas hook directly to the fuel rail. Disconnet the retun line from the fuel rail and make it feed the one gallon you have. Completely eliminate the fuel system other that the one gallon.
How is the tank and lines? Did you ever drop the tank and clean it out?
Take an extra fuel pump and from a gallon of gas hook directly to the fuel rail. Disconnet the retun line from the fuel rail and make it feed the one gallon you have. Completely eliminate the fuel system other that the one gallon.
Thread Starter
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From: lemont, Illinois
Didn't drive it. just saw the base pressure hold. The tank was dropped and opened up. So it is clean in there. Cleaned the fuel lines. But I wonder if maybe the intake dump has damage and is sucking some air... Or a crap pump or just the fpr. Didn't get much time to play with it. Gonna have to try n do some work in the am. And yah that needle drops to 0 instantly when the car starts to stall. Craziness thing ive ever seen. Like once the duty cycle on the injectors kicks in there is just nothing behind em anymore.
