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Mobious5

shaved intake 280zx, now won't start

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0331091730.jpg

 

hey guys i need some help. basicly somewhere down the line i got the crazy idea to shave an n47 intake and slap it on my p79 head with no cold start, i dle control, pcv, nothing leading in or out the top side of the throttle body. the results... drum roll please......

the car wont start.... or it will, only after holding the gass down and after getting it to start continously tapping the gas to keep it going....

 

here are some pics of my setup..

 

looks ok, but isnt

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blocked egr

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block off plates on the intake and throttle body,

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blocked off hose coming from the coolent housing

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kept the breather from the block and left the inlet under the throttle body open (should probly go the something)

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like i said nothing hooked up on top of the tbody

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nothing hooked up to the cold start.

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blocked off egr on the exhaust manifold

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left this metal pipe open, i dont no if i should block it off or hook it up to something.

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my gay welder and paintin stuff

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here are some vids, check em out

th_VE_0331091722_01.jpg

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sooo basicly i need help with this hole thing because spring break is coming up in one week and the ladies love 280's.!

thanks guys

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1st off, in the second pic to the right of the yellow tape, that ground is for your fuel injectors. It closes the loop, if it's not hooked up, your injectors will stay wide open. Next, you need to check all of your open piping off the TB for vacuum leaks. Then disconnect and remove the AAC valve ( the silver thing next to where the cold start injector was). It is OK to leave the AAC and cold start unplugged. If I think of anything else, I'll let you know.

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Good grief... faint.gif Where to start... scratch.gif

 

This hose outlined in "MAGENTA" is going to cause a VERY high Idle speed once it does get running. Either cap it at the manifold and boot or plumb the Air Flow Regulator into it.

 

WOW.jpg

 

 

.... Uh... well... I have to run now... yeah.. go pick up Melanie from school..

 

BRAAP... OUT!

 

:burnout:

 

:burnout:

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Good grief... faint.gif Where to start... scratch.gif

 

This hose outlined in "MAGENTA" is going to cause a VERY high Idle speed once it does get running. Either cap it at the manifold and boot or plumb the Air Flow Regulator into it.

 

WOW.jpg

 

 

.... Uh... well... I have to run now... yeah.. go pick up Melanie from school..

 

BRAAP... OUT!

 

:burnout:

 

:burnout:

 

Good catch! Missed that one! I'm still trying to find some more things that are wrong with this!

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Oh man I feel for you. I have dug myself into some holes but you got yourself a lulu.

 

I was under the impression that the magenta hose goes from the manifold to the carbon cannister.

 

I am pretty sure a PCV valve is necessary for operation but I could be wrong.

 

Your air hose schematic just looks...wrong.

 

Maybe drop $50.00 on a service manual specific to your vehicles year and start from scratch.

 

Good luck...

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Yes Service manual. And looks like some grounds arent connected. Hosing dosent look right. hmmmm you didnt leave anythign in the intake right hehe just asking .. it happens. ummm Wires all right order? also Try adjusting the TPS or AFM check plugs what do they look like.. soiled? black? SO many things man... and that tube on bottom of manifold is open if I heared you correct if you have open airflow past the TB and the AFM then its gonna totally read the wrong airflow cause it will be sucking in air from any open holes and bringing to much air in thinking its running fine lol.. ooh wait I looked again I thinkg thats the Block tube.. not sure try to keep pics on same angle.. my neck hurts lol.. also is that hose coming from the fuel pressure regulator hooked up? looks to be just hanging down to no where...

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I guess Ill ask here since I asked in your other thread and it went to the tool shed...

 

What is wrinkling on the manifold? Did you just use normal paint rather then high temp paint? Or is it something else?

 

 

The wrinkling paint came from alittle fuel that dripped down. after i bolted everything back up... i probly could of avioded that. i did although use high temp paint.

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Yes Service manual. And looks like some grounds arent connected. Hosing dosent look right. hmmmm you didnt leave anythign in the intake right hehe just asking .. it happens. ummm Wires all right order? also Try adjusting the TPS or AFM check plugs what do they look like.. soiled? black? SO many things man... and that tube on bottom of manifold is open if I heared you correct if you have open airflow past the TB and the AFM then its gonna totally read the wrong airflow cause it will be sucking in air from any open holes and bringing to much air in thinking its running fine lol.. ooh wait I looked again I thinkg thats the Block tube.. not sure try to keep pics on same angle.. my neck hurts lol.. also is that hose coming from the fuel pressure regulator hooked up? looks to be just hanging down to no where...

 

yea, ive dug myself a pretty deep one. I noticed that i didnt properly ground everthying. and im pretty sure your right, the hoseing is way off. to be honest i thought i could re route some of the lines back into the intake without caping off some of them. esp because i didnt hook up the idle controls. hopeing that the car would just idle normaly without all that other stuff.

lol my fault about the angle, and the preasure regulator is hooked into the intake between the 3rd and 4th ports

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1st off, in the second pic to the right of the yellow tape, that ground is for your fuel injectors. It closes the loop, if it's not hooked up, your injectors will stay wide open. Next, you need to check all of your open piping off the TB for vacuum leaks. Then disconnect and remove the AAC valve ( the silver thing next to where the cold start injector was). It is OK to leave the AAC and cold start unplugged. If I think of anything else, I'll let you know.

 

your right i forgot about those grounds, so its ok to not even have the AAC valve? nothing running through it and unplugged?

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Hello Mobious.

 

When you run a shaved manifold and do not use an Idle Air Control, the car will not idle or idle really really low at colder temperatures. I ran a shaved manifold for a while in Baton Rouge but didn't realise it affected startup until I moved up here to Arkansas and experienced really cold weather.

 

Everything else held constant, and you don't have any other issues [grounds and other things listed above] than you can do a couple of things.

 

You can adjust your throttle body plate stop so more air will get through, but this will make your car idle really high when it warms up [i prefer a 700-800 RPM idle when warm]. I have come up with a really ghetto solution for this but do not want to post my shame here on hybrid. I have told someone else what I did through PMs if you care to know. It involves vacuum lines, not a big deal.

 

Good luck, enjoy your Spring Break!

 

*EDIT* Alright, honestly I didn't see all the pictures before I posted. You have the IAC sitting on top of your shaved manifold, not hooked up to anything but the EV connector. Whats the point of a shaved manifold, brotha? This is my current set up on my old motor:

http://s254.photobucket.com/albums/hh81/flatblack280/Shaved%20Intake/?action=view&current=100_2475.jpg

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Mobius5,

Here is an intake swap with a 60mm TB conversion I just completed yesterday for a local customer. Some of the details may be of help in your project. Local customer located a non-EGR N-42 intake, 60mm TB, Pallnet fuel rail and TB spacer kit then dropped the car off and wanted it installed and tidied up similar to what we have done for many others, including rerouting the EFI harness along the firewall and under the fuel rail instead of over the middle of the plenum. Fired the car up yesterday, runs great, just as it did when it came in, other than the deleted air flow regulator as described below, other than that, no differnet! :2thumbs:

 

This is a bone stock L-28 EFI.

 

Items deleted;

1) EGR, (This is a ’75 car registered outside of CA)

2) Air Flow Regulator (for a cold idle speed that the engine will idle on its own without holding the gas pedal, a "warm" idle speed has to be approx 1000-1200 RPM on a properly tuned L-28. If a warm idle speed of 650-800 is desired, then you’ll have to hold the gas pedal to keep the car running when cold till the car warms up, or reinstall the Air Flow Regulator.)

3) Coolant by pass that ran under the Air Flow Regulator.

4) Cold start injector and Thermo time switch. Tapped the cold start injector hole for 1/8" NPT, brass pipe plug installed. (left the Thermo-time switch in the thermostat housing, just deleted the wiring.)

5) A/C equipment in the engine bay.

 

Items rearranged; but still functioning as OE!

1) Carbon Canister vacuum line has new port drilled and tapped into the back of the plenum and vacuum line rerouted along passenger frame rail and across the lower firewall.

2) Fuel Pressure regulator relocated to the firewall, fuel rail plumbed in a pseudo dead head style arrangement, (before anyone jumps on the “dead end EFI fuel systems cant be done” bandwagon, SEARCH! It can, has, and is still being successfully done, by the OE and tuners such as myself with NO ill effects NO vapor lock etc). Vacuum port of the FPR also has its own new dedicated vacuum port added to the back of the plenum next to the canister port.

3) PCV is now drawing fresh air, K&N filter on valve cover. (This caused the engine to ingest "false air" as the air being drawn in through the PCV system is no longer being measured by the AFM, yet the engine is breathing that air, i.e. “false air”), as such I will be fine tuning the part throttle tune with a combination of the water temp resistance and AFM adjustments, todays project. For those new to the stock EFI or EFI in general, just leave the valve cover breather plumbed to any port between the Throttle body-butterfly and the AFM and you’ll be just fine!

4) Removed the EFI harness and removed the outer sheathing from the harness that resides in the engine bay. Deleted the Thermo-time switching wiring back to the splice, also deleted the cold start injector wiring. (Just leave the wires cut, but protected from grounding/shorting. The computer doesn’t know the difference nor does the engine.) Separated the injector wires and the water temp sensor wires of the AFM and TPS wires into two separate runs. Retaped those as 2 runs. Reinstalled harness, routed the injector and water temp wires along firewall and then under the fuel rail, (can’t even really see them in this photo below, but they are there) and routed the AFM and TPS wires back in the stock location.

 

Customer wasn’t ready to for a shaved intake, so this one was just painted and installed. Original fuel pressure regulator port plugged as well as a couple other deleted vacuum ports.

 

Here is the picture, below that is a diagram of the dead-head fuel rail system.

 

Boot between TB and AFM is not secured in picture, it needs to be secured!

Running.jpg

 

Returnless.jpg

 

 

 

Hope this helps,

Paul

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Thank You brapp from me as well! I must have 20+ bookmarks on this process alone and you summarized it quite nicely.

 

Wow, thats great information brapp! That will definitely help me and many other when it comes to the point of adressing the engine. :)

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Hey guys i lost my key so i ended up getting a new ignition switch before i could start the car again.. After i poped that in i made a couple corrections. i grounded everything...

 

 

0419091137b.jpg

 

 

then i plugged the two holes on top of the afm-tb connecting tube.

 

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Then i attempted to start the car and it did the same thing, it wouldnt stay on un less i held the gas.

 

while doing this i heard a whistleing sound. it turnd out the be the pipe on the bottom of the TB thats supposed to go into the idle control valve. this

 

0419091001.jpg

 

now ive tried serveral things like plugging it, running it back into the intake,leaving it open... etc nothing works. but this is why i think this is my problem is because when i hook this up...

 

0419091000.jpg

 

this is the only way i can get it to idle, and at that, it on idles at 300 rmp just bearly on...

 

how do i control the idle or am i missing something, because the car will start but it wont hold unless im on the gas.

 

thanks hybrid

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yea i tried that but cant get it to idle anywhere above 500. and it only raise that high when i put thumbs over the ends and barely let air through.

it seems as if everyone who does this has done it with 240 TB's.

 

If i've done this right should there be ANY vacume lines leading into the throttle body???

thanks

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Mobious how cold is it over there? Im telling you without the IAC it is going to idle really low until the motor warms up. When it is warm its not much of a problem but will still idle a bit low at start up. If you adjust the idle screw its going to run at higher RPMS at normal running temperature.

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To get my car to idel properly it was a fun game of adjusting the afm, that idel screw, and timing.

Without proper tools I have her running very good! I'm na so not toooooo worryed about detenation.

 

A dyno party is coming up, so I will get to see how badly I suck, or.........

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