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L28ET swapped 72 240z idling funky & lack of power


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Hey Guys, well, i've reached a point in my project where i just had no clue what to do to get it running right other than to take it to a shop. Long story short.... The car has idling problems/ boost leak problems?e Car turns on and runs and can be driven. But the car definitely has a major lack of power as boost gets nowhere near stock psi. i checked for major leaks with a home made boost leak compressor based gadget to test leaks on piping from turbo running through inter-cooler all the way to intake plenum.  gauge on tester goes down very very slowly but Not sure whether or not that should cause such significant lack of power. Car when driven barely gets to spool much boost, let alone set off the greddy type S BOV.  there is fuel, there is spark. Timing i can't even get done accurately since the car idles and runs, spits, like crazy . seems like it the problem is aiming toward a boost leak problem; however, this project having been done from ground up by me and being my first swap, the margin of error remains.... electrical wiring schematics were gathered from intel from this site based on previous wiring diagrams from L28et to 240z swaps. 

I took it to a Datsun specialist shop here in (SAN DIEGO, CA 91911 )nearby that has remarkable yelp feedback and honest to god the owner of the shop seemed like a knowledgeable  great guy and interested to fix on it.... but after 3 months of waiting i was dissapointed to hear he was unable to get positive results as (and i quote) " specialize in N/A for the most part" which would've been nice to know prior to wasting my 3 months -_- ANYWAY! 

Does anybody know of a good shop here in SAN DIEGO, CA area that does honest and good work on 240z's in a timely manner for a decent price? or anybody who could take a look at it and figure out what needs to be addressed. the wrenching i can do. but with the TIME i have free it's just not feasible for me to LOOK or TROUBLESHOOT. i need someone to say " THIS, THIS, and THAT. i can get it fixed for _____and running right,  otherwise its ____ for the diagnosis and have a nice day. 

HELP!

 

Here's a link to a youtube Video of the car when i took it for a short ride to the end of the block, as you will notice, the car had issues staying on when cold. hopefully by hearing it maybe some of you could throw some educated guess/recommendation

 

http://www.youtube.com/edit?ns=1&video_id=y79Rjd1uI60

 

Some pics. 

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I'd check compression(and leak down) of cylinders, fuel pressure, tps, chts, afm, and shaft play on turbo.

 

I'd also try an ecu you know has 0 problems just to rule that out.

Also, have you pulled the spark plugs? How do they look?

 

A boost leak wouldn't cause idle problems unless it was huge, it just wouldn't build boost that fast if at all.

Edited by Milenko2121
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I'd check compression(and leak down) of cylinders, fuel pressure, tps, chts, afm, and shaft play on turbo.

 

I'd also try an ecu you know has 0 problems just to rule that out.

Also, have you pulled the spark plugs? How do they look?

 

A boost leak wouldn't cause idle problems unless it was huge, it just wouldn't build boost that fast if at all.

I totally agree with you i doubt the boost leak us huge IF there is one. The mechanic i took it too did tell me he did a compression and leak down and everything came out fine; however, i am not sure or have any proof whether the guy even bother to touch the car at all while he had it at the shop. I did a shaft play test and moved it around to check the condition of the shaft while the engine was in the hoist and no shaft play at all was noticed. Fuel Pressure was something il take a look at next since it should be inexpensive. AFM should be fine. I have two more spares laying around but ill switch them around and see if anything changes performance wise. Wish i had a spare ECU to be honest, at this point i wouldn't be surprised if that was the problem "maybe". Sparkplugs last i checked were moist with gas so an abundance of gas is definitely being sprayed, which is what brought me to the assumption of boost/ vacuum leak, causing the engine to acomodate by spraying more fuel ? 

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"Timing i can't even get done accurately since the car idles and runs, spits, like crazy . seems like it the problem is aiming toward a boost leak problem; however,"

 

A boost leak is not the cause of a car spitting at idle.

 

You even said it yourself, after using a leak tester you found there to be no leak.

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Ok, the spark plugs are wet with gas, possible sign of running too rich which I'd suspect the AFM or fuel pressure regulator, most likely the afm though, to be the problem.

What color are they? Black, White, Brown?

Do they have any oil on the tip?

 

Check your AFM wheel and see if the old glue has been removed and someone turned the wheel to run richer. If they didn't I'd break the glue and play with it.

 

Here's a guide for tuning it. It's very simple.

http://atlanticz.ca/zclub/techtips/afm/

Edited by Milenko2121
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"Timing i can't even get done accurately since the car idles and runs, spits, like crazy . seems like it the problem is aiming toward a boost leak problem; however,"

 

A boost leak is not the cause of a car spitting at idle.

 

You even said it yourself, after using a leak tester you found there to be no leak.

Correct, it seems i'm going to have to time the car correctly first as i just found out on another forum that it seems my dist shaft tooth needs to be adjusted one tooth over? or the timing chain needs to be adjusted one tooth over? the sparkplugs are grayish/ black moist with fuel, which i believe the car is running too retarded?  

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So i bought a timing gun. and went through some forums with timing problems and adjustment posts for timing. I proceeded to get new plugs, i gapped them to specs according to haynes. i installed new cap and rotor. (new MSD Blaster 2 coil and Magnecore wires ordered ). Plug connection, and finally disconnected the + battery terminal and brushed the ECU pins and plugs. i reconnected everything, i removed the sparkplugs as indicated, i placed cyl 1 in what appears to be TDC and took some pictures. 
 
Based on these pictures, is everything where it supposed to be? because when i put the timing light on the area to adjust (even with white out on the crank pulley timing mark) the mark was nowhere to be seen. 
 
I figured i would start with getting the timing done right and get the ignition based margin of error out of the way

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if you can't see your timing mark, it's possible the harmonic balancer seperated from the pulley. I've had that happen before. good way to test it is to make a new mark, and see if it moves. Mine would slowly spin all the way around and come back.

 

Your shaft looks correct though.

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if you can't see your timing mark, it's possible the harmonic balancer seperated from the pulley. I've had that happen before. good way to test it is to make a new mark, and see if it moves. Mine would slowly spin all the way around and come back.

 

Your shaft looks correct though.

questions might seem dumb but ive been curious for a while., but is "normal" for the crank pulley to wobble a little? 

and hmm.. i had a feeling timing couldn't be WAY too far off that badly, the car wouldn't even start or stay on from what ive read on L28ET timing related threads. 

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  • 2 weeks later...
~UPDATE~ 

 

So today i decided to go all out in making sure the timing on the car was not the problem with the performance of the car. So i proceeded to take the radiator/ fans off etc and take better pictures so i can get some feedback. I refered to other sites and information gathering such as:



 

And i came to the following images upon tempering with my crank pulley. I noticed that the shiny link lines up in the middle of dot 3 on the cam gear. Also i was for some reason after continuous checking and crank pulley turning. and lighting with a flashlight, i was unable to find the "groove" on the back of the cam pulley through the holes. I located the stationary mark on the cam retaining plate, but saw or found none on the actual cam sprocket;therefore i was unable to align or check for that.After refering to Website #1 im thinking either the chain must have been replaced, the head must have been redone, or the engine rebuilt....or ? 

FEEDBACK Please? 

 

IMAG0559.jpg

 

IMAG0561.jpg

 

IMAG0563.jpg

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And i came to the following images upon tempering with my crank pulley. I noticed that the shiny link lines up in the middle of dot 3 on the cam gear. Also i was for some reason after continuous checking and crank pulley turning. and lighting with a flashlight, i was unable to find the "groove" on the back of the cam pulley through the holes. I located the stationary mark on the cam retaining plate, but saw or found none on the actual cam sprocket;therefore i was unable to align or check for that.After refering to Website #1 im thinking either the chain must have been replaced, the head must have been redone, or the engine rebuilt....or ? 
FEEDBACK Please? 

I've noticed the same about the sprocket on my F54/P79 engine.  The V notch described in the early FSM's (visible on my N42/N42 engine) isn't visible.  But if you look through one of those holes and down at the back of the sprocket I think you'll find a square cut notch that should line up with the mark on the retaining plate.  It did on my engine.  Seems like Nissan went to a different sprocket design and stopped recommending the V-notch check for timing chain stretch with the F54/P79/P90 engines (can't find it described in the ZX FSM's).

 

I don't think the position of the shiny link matters once you spin the engine a few times.

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