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Turbo spools, car doesnt go.

980 Views 26 Replies 12 Participants Last post by  zxreg
I have a 1983 280zxt.

Engine is a rebuilt factory block with a p79 head.

Turbo was checked upon engine rebuilding and is 'free moving'.

Spooling sounds just fine, will boost all the way.

When the turbo does kick in the car doesnt go anywhere, driving w/o spooling the turbo the car does just fine as if a normal n/a.

Any suggestions on what I should look at?

Is it a vacume problem?

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Ok just to make sure I looked at the right parts, I don't have a manual here so I'm going from what I know..

The POV is ontop of the intake manifold? Its near the back next to the ERG Valve? Its top 'moves' to release the pressure, that unit is secure and not leaking any air.

Wastegate I have no real idea where it is.. I thought it was the pipe exiting the turbo to the rest of the exhaust? Thats secure, no leaks there.

it's the gold thing mounted on the intake side of the turbo with the shaft goin to the exhaust side.
he said it boosts all the way......are you talking about the gauge?? it goes all the way??
verify the ignition timing
Wastegate looks fine, no leaks, all seals are tight.

The gauge shows full boost, turbo whine sounds good, sounds like the turbo is doing its job but the rest of the car isnt?

Ive checked the timing already and have been adjusting it to see if any changes are made, none that I can see.

Anything else?

could it be possible that the wastegate is stuck open?
How could I tell if its stuck open? I'll go examin it more.
If the wastegate was stuck open would the turbo even spool up? It sounds to me like you have a problem with the EFI. Clean all of your electrical connections, especially those at the ECM. My other thought is that with that cylinder head your are getting detonation and the ECM is retarding your timing, resulting in low power. Give us some more details on what exactly the car is doing. Where is the P90 head that originally came on that motor and what compression ratio are you running? That P79 head was for a n/a motor.
I don't know the answer to that aas a fact, but it should still spool as all it does is bleed off excess pressure, and if it stuck open at the stock boost level, it should still spool up.
take the clip off of the end the rod and see if you can move the rod towards front of car and to the rear..... does it move easily are take some muscle to move the rod... the rod is suppose to be ...at regular position back inside the wastegate and move back towards the end of the car to open the door lever on the turbine side. if the door lever is at the open position when your car is running, then that means the door is always open....no power
The turbo spools guys.... the gauge wouldnt move if it didnt...it runs just fine like a non turbo right?????

My 83 was like that when i got it....if you spooled it...then let off the gas then slowly put your foot in it...it would take off...it turned out to be ignition problems, Im pretty sure it was the crack angle sensor in the distributor, I replaced alot of parts but im almost sure thats what it was..

Does it run fine??? or does it make noises or miss or anything....if not....then its prolly not fuel...good luck
Yes it runs like a n/a..

When I start driving it drives fine, turbo beings to spool and as long as im 'boosting' there is no 'go' to the car, once I let off the gas and the boost drops back to 0 or below the car goes [as no turbo is there].

Once the turbo kicks in it doesnt move, if I mash the gas it goes, full 8psi of boost [did it once or twice, dont want to do it again] .

I dont think its fuel at all, atleast gas getting to the engine.

Not sure if you can see if the crank angle sensor is bad or not, I took the distributer off today to put on a exhaust manifold nut, everything looked fine, I think it was replaced with the new engine, I have one from a n/a but that wont work ;)

I took the rod off the wastegate, very very hard to move front/back, I could move it maybe 1/4 of an inch. It took some force to get it back on the 'pin' as well.

Can I drive with the lever off and some how lock the wastegate closed? Atleast to see if that will fix it? Or is that a bad idea..

About the p90 head, I do not have it, the p79 was put on from the rebuild shop? I think.. Is this a bad thing to have the p79 head? Is the p90 going to be better?

Thanks for the responce guys :) I owned a 280zx n/a about 4 years ago, did a ton of work to it then someone crashed into it and got it totaled, I gave up instead of fixing it.. Now im back in action with a Black 83 280zxt t-top, very very happy.. Just want to get the car in good running condition before I park it for the winter while I rebuild the whole thing :)

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Can this be related to the vacume hoses at all? I ask since they may not be hooked up correctly [tho I think they are].. I'm going to take a picture and post it after I run to the store.
did you check your ecu connections? i know from experience that dirty ecu connections will give the same problems that you are having.
Not the greatest picture but the only one that came out decent.. I shake to much.


Post Edited (Nov 11, 10:03pm)
< http://gamecp.com/carphotos/DSCF0050.JPG >, without the spaces makes for
Sounds to me like you have a problem with your timing vac advance
the turbo efi doesnt have a vaccum advance
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