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[new title] 77 280z w/ l28et regeneration


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#41 brapattack

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Posted 11 January 2017 - 03:57 PM

I put in one of the aeromotive FPRs with a vac line when i put in the fuel rail i made.  So I can see that the fuel pressure isn't dropping when I rev and release the throttle.

 

I am thinking it could have to do with the AFM adjustment, a vac leak somewhere or electrical connection.  The idle also sometimes hangs up at 2k when I release the throttle.  It will sit there for a second or two then drop.  When this happens I can see that the AFM arm sits at a spot before dropping down...Not sure if this causing the hang-up or just an effect.

 

 There are just a handful of janky areas from previous owners so its taking me a while to figure out what each component is supposed to looks like when adjusted correctly.



#42 Bleach

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Posted 13 January 2017 - 10:05 PM

I think the AFM arm is holding open due to the rpm of the engine. The air passing by is what keeps the AFM arm up. (that's its function)

 

My guess would be a vac line somewhere. I had modified some of the emissions lines on both turbo L28s, so I blamed myself.


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#43 brapattack

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Posted 14 January 2017 - 08:17 AM

I made a possible breakthrough. I was trying to set the TPS again and was getting strange continuity readings so I took it off to take a look. The black plastic case was broken off a 1/4 of it so I could watch the mechanism inside.

Some of the plastic parts were worn so when the throttle opened, the pieces would only occasionally catch and move as they were supposed to. This led to it being stuck in one position or another, rather than responding to the throttle position.

Unfortunately these parts are hard to find in the z stores, had to cough up way too much $$ on the eBay. Hoping it's a leap forward though.

#44 Slowpoke

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Posted 14 January 2017 - 08:34 AM

Nice job and good find on the tps! If you still have the pop off valve on there check it for vac leaks. You can plug it with a pipe end cap. Also replace any vac hose that seems dubious.



#45 CGraves

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Posted 14 January 2017 - 11:32 AM

Is the TPS the same on a regular L28 as a turbo? I have an L28 on a stand with the Fuel Injected parts which I don't plan on using. Lemme know if you want me to take a look.

 

 

Edit:Nevermind I'm stupid and can't read. You already bought one on ebay.



#46 brapattack

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Posted 14 January 2017 - 04:45 PM

Hey Cgraves, thanks, I think they are the same unit but the turbo only uses two wires rather than 3.  If i hadn't already bought the ebay one id throw you some $$ for yours!

 

Slowpoke, I still have the BOV, was going to remove it but wasn't sure what to plug it with yet.  Looks like a big hole, any idea what the threads are?



#47 brapattack

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Posted 22 January 2017 - 07:49 AM

Okay, got the new TPS in and it really helped with the idle.  Now the car doesn't turn off when rolling to a stop!  

 

The throttle response is still weird if you just stomp on the pedal.  Just bogs to nothing until you let off and let it slowly rev up.  Not sure if this is an AFM adjustment or what but at least its drivable.

 

I ordered some of the Konig rewind wheels.  I was trying to decide between 15 or 16" for a while but since i'm not going for a real performance oriented setup, I decided to go with 15" and will use a little taller tire to nicely fill the wheel well and provide a little more comfort.  I figure these old suspensions weren't designed for the real short sidewalls that are popular on modern cars.



#48 Slowpoke

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Posted 24 January 2017 - 06:16 AM

I would keep checking for vac leaks, I has about a hundred when i did my swap. Did the ol cigar smoke test, helped me find a couple of them. For the pop off valve, i just took it off and brought it with me to he hardware store. BTW the pop off vale and the blow off valve are different parts. L28et's have both. I think you have the correct part though. The pop off valve is located on top of the intake manifold toward the firewall.



#49 Bleach

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Posted 24 January 2017 - 09:50 AM

One spot that I had vacuum leaks on was at the injectors. Right around the holders themselves. Had to add gasket dressing to the rubber rings themselves to fix it.

I also was noticing boost leak and it was at the injectors of course. Took me forever to find that one!


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#50 brapattack

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Posted 10 April 2017 - 07:26 PM

hey its been a while, I have been away from home on a job for the last couple months.  Here is my 280z as it wis with its new wheels and louvers.  I also put in new lower rear control arms because I found that the driver side had soem crazy toe-in and the stock arms had no adjustment.

 

It looks like I am going to be off of work for about a month so I am going to go on a roadtrip in this thing.  Its definitely got some weakpoints but I will just see how far I get and what I can fix myself along the way.

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#51 Slowpoke

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Posted 14 April 2017 - 04:25 AM

Oh yeah, Try doing a smoke test for vac leaks. That one helped me find a few. Block the AFM inlet with something (plastic wrap and a rubber band), then use a cigar to blow smoke in a vac line. See if the smoke leaks from anywhere.



#52 brapattack

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Posted 22 April 2017 - 07:51 PM

Yeah I should probably do the smoke trick.  Currently trying to get the stock pop off valve off so I can block that hole.  Its hard to get my boost up and to stay up.

 

Got a 240z front bumper mounted. 

 

My heater core valves were leaking and getting "new" ones or rebuilt ones is expensive so I am putting in a 3 way ball valve with some hoses to basically have an open to shut to the heater core system.  Trying to figure out with of the little vaccuum hoses in there go where so I can actually select which vents vs defrost might be tricky as the three i found weren't attached to anything.



#53 brapattack

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Posted 01 May 2017 - 07:31 AM

I'm a couple days into the road trip in the 280z and I've found that my mileage when I cruise around ~75 is 18.5 but if I cruise above 80 it drops way down to the 14s. I think I must still be running rich or something cause it should be better. Slowly dialing down the Afm and fuel pressure to see if that helps.

Car is running plenty cool and oil pressure has been good. I am losing brake fluid from the front brakes system. There are no leaks at the wheels and the master cylinder is also new and showing no leaks. Trying to find where in the hardline must be seeping.

Oh I should take a picture of my heater hack and will upload some photos when I have computer/wifi.

#54 brapattack

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Posted 02 May 2017 - 05:02 PM

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#55 datzenmike

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Posted 03 May 2017 - 05:28 AM

I'm a couple days into the road trip in the 280z and I've found that my mileage when I cruise around ~75 is 18.5 but if I cruise above 80 it drops way down to the 14s. I think I must still be running rich or something cause it should be better. Slowly dialing down the Afm and fuel pressure to see if that helps.

Car is running plenty cool and oil pressure has been good. I am losing brake fluid from the front brakes system. There are no leaks at the wheels and the master cylinder is also new and showing no leaks. Trying to find where in the hardline must be seeping.

Oh I should take a picture of my heater hack and will upload some photos when I have computer/wifi.

 

Probably normal mileage. Wind resistance goes up 4 times when you double the speed. Wind resistance at 80 is four times what it is at 40. Adds up fast.


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#56 Bleach

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Posted 04 May 2017 - 08:45 AM

I never had an S30 long enough to do a fuel economy test. My 280ZXs with a 5-speed were getting around 26-29 on the highway. Generally I was at 65-70mph. Stock 3.9 rear gear.

Now I briefly had the non-turbo engine with tall 5-speed and 3.54 rear, lowered car. I got over 30mpg on the highway. After the turbo swap I never saw those high numbers again.

 

My guess is that you should be in the low 20's or better if things are running correctly.


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#57 brapattack

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Posted 22 May 2017 - 10:13 AM

Okay, been doing lots of driving.  Currently about 4500 miles on the trip so far and going pretty smooth.  I replaced my fan clutch in southern california cause it had seized but hadn't thrown the fan to pieces yet.  Only other thing is I have to keep topping off the disc brake master cylinder, going to put in a couple new hardlines while I am here in CO.

 

After fixing my timing and adjusting the AFM/fuel pressure a bit my MPG seems to hover around 20-22.

 

IMG_6837_zps9doaiovo.jpgIMG_7014_zpsfs6ptwjc.jpgIMG_7068_zpsmrvaj62m.jpg



#58 Bleach

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Posted 24 May 2017 - 07:35 AM

Wild and free!


Thank you Ted!
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