Bleach

I'm starting a new thread for my turbo problem instead of continuing on the turbo swap thread...

I installed the fuel pressure guage. I get 36psi of fuel at -18 psi at idle.
With the hose off (no vaccum) the fuel pressure goes to 46psi.

The FSM says vaccum should be -30 at idle and only 30psi of of fuel pressure.

Those of you with vaccum gauges; what is your pressure at? And your fuel pressure?

if my vaccum is too low, then I probably still have a leak. The car idles great though and I've sprayed that carb cleaner all over with no change in idle speed. I even rechecked the manifold bolts.

NismoPick

My vac at idle is about 18mmHg. I have an adjustable FPR & have my fuel pressure set to 40psi.

KTM200-280zxt

am I missing something why is this in the S30 forums?

NismoPick

yeah... dunno... Bleach is Bleach!

Bleach

oh my, I first posted this under the Suspension/Wheels in the 280ZX section and then moved it... but accidently moved it to the S30 forum! oops!

ok, moved again...

Bleach

so you set your idle fuel pressure to 40? that's 10psi over what the factory manual says it should be. I would think that runs fairly rich at cruise.

NismoPick

It runs QUITE well actually... Remember tho, I now have a larger turbo & the Z31T ecu.

When your fuel pressure goes to 46psi, does it run better?

Bleach

no, because when I floor the pedal that brings the vaccum to zero.... and it starts to buck at about 3 or 4 psi. This is the same FPR that has been installed all along. so I'm starting to think my fuel pressure is not the problem.

Are you guys sure the fuel pressure isn't going to raise if I put some positive pressure on the FPR? I could try it and see what happens. There isn't much on how this thing opperates in the FSM. It goes over the non-turbo setup and doesn't really say anything for the turbo so I assume it is supposed to opperate at the same psi out of boost as an NA engine.

I could crush this FPR a little to raise the pressure... and maybe that'll fix the problem at boost but with my stock ECU I'll be running a bit rich at idle and cruise. I don't want a 18 mpg turbo Z.

...I totaly forgot to swap out for the extra AFM in Dicesetter's parts car just to see if that fixes the problem! duh

veyenyl

Are you running the N/A or turbo FPR? I believe the turbo FPR is 1:1 rising rate under boost.

In my old stock setup, whenever it would buck it was the connector at the AFM or the ECU connectors. After I would clean both the bucking would go away.

Did you check the AFM resistance values against the FSM?

thxone

Check this first!!! My Turbo Ranger would buck and pop and fall on its face when it started to make boost. I forgot to tighten down the clamps on the intake tubes after the turbo. So when it pressurized it came off the T/B and would not run well at all. Also at like 3 psi of boost.

nismo619

on my 82 280zxt on the JSK FUEL RIAL it idels at 32 psi fuel when i rev it up high to about 5,000 38 to 40 psi.. ive never had ap roblem with my 82 thou... check your ACC valve to see if its sticking ? it might have somthing to do with a valve on your intake manafold.. just a thought... no body bag on me please lol

Bleach

Yes, it is the turbo FPR. Everything is turbo. It is a complete turbo engine (stock) from a turbo parts car.
also, I noticed the return pipe on the turbo FPR is slightly different angle than the NA. I have two other turbo FPR (stock) and they are all the same way. My two NA's are different so I'm pretty confident this is not an NA regulator. I realize previous owners can swap out parts when they're cheap and don't want to do things right.

I'll check that J-pipe connection again. I got it nice and tight when the engine was out of the car but have not checked it since. I did re-check and made the clamp tighter around the throttle body part.

AAC valve is gone and blocked off with a plate. I checked the nuts that hold it down and sprayed carb cleaner around that plate and the EGR blockoff plate while the engine was idling. All appears well there. The AAC unit below the engine is still plugged into the wiring harness as NismoPick suggested.

I've reconnected and cleaned the ECU and AFM connections a few times in the past couple weeks. I even opened up the AFM and did the quick fix that J posted about rebuilding the AFM. This one actually looked very good. hardly any mark on the carbon line and the insides look new.

I did not know about checking the resistance on the AFM. I'll look that up and try it. thanks..

veyenyl

Also double check the connection from the AFM to the turbo. I had a cheap acordian type hose on my car when I first bought it. It eventually tore and it would sometimes buck under low boost.

81 Black L28E

bleach ...trush me ..you need a fpr like mine and nismos! you cant put a bigger rail on there and have it run right with out it !!....i run at 35 psi and iam not running rich at all in fact i could turn it up to just about 40psi and it pulls a little harder ..i have it turned to 35psi to save alittle gas l ..if there isnt the right mount of fuel going though the rail back into the tank then your injectors will run lean ..if there is to much they will run rich ...i found this out buy checking my plugs every other day... when i frist check them they where white ...after turning up my fpr to 35 psi insteed of 30psi stock ..my plugs changed color to a browner looking color .i could tell right way that my car was better from doing this ..the rails tubbing is bigger witch means more fuel needs to flow though the rail back to the tank ...right now i have no black smoke awsome idle and a great deep tone when reved .... if i step down on her and watch the air fuel gauge the bar will jump and stay at the frist rich bar untell i let off the gas ..then it goes back to cycling like always ... if i turn up my fpr it will read one more bar on the gauge ..i have never gotten to the last bar only the frist two .. but i think i could with out it being rich ..As my gauge cycles durning normal driving i goes from lean to ideal ..only when i step it to the floor does the gauge jump to the rich zone if i let off it goes right back to the cycles.
when i was running 30 psi with jsk rail i couldnt hear my injector with the hood off now that i run 35psi i can hear them ticking away ..if i run it at 40psi they sound strong and it pulls really hard ...if i turn up the fpr my idle goes up so you have to turn down the trottle body screw or turn the diss down a little ..i did both untell i found the spot that sounded right for my z ...my time slips from the drag race showed me i was right ..each time i did a run i ajusted things and did another run ..i could see my car get faster mhp each time ..along with my air gauge showing me that everything was a ok ....
TRUST ME ORDER A FPR AND TURN IT UP TO 37PSI .WHEN REVED IT WILL REV TO 42PSI OR PUT YOUR STOCK RAIL ON AND RUN THAT CRAPY BLUE REGULATOR ..

to much air not the right mount of fuel you need more fuel and less air !

UNLESS YOU MESSed UP ON WIRING THAT BEAST OFF THE GET GO !
but i dont think that is the case .
the reson that there isnt much in the books about the turbo's on these cars is because there isnt much to it ...plug and play for back in the day !..all they had to do was change the compression ratio .

jfairladyz

Have you checked timing under boost??? What grade of fuel are you running??? Whats your base timing at???

81 Black L28E

i just have to say Bleach you can do it dont give up .....


ALSO TO ANYONE THAT ONLY HAS 500 OR LESS POSTS DONT POST HERE ...
BLEACH KNOWS ALL THE STUPIED THINGS AND NEEDs THE HELP OF SOMEONE THAT KNOWS WHAT IS GOING ON ie someone with 1000 posts or more
If this is not U THEN dont post on this tread ...NOT BEING RUDE TO YOU AS NEW MEMBERS but WE OLDER MEMBERS KNOW THAT BLEACH KNOWS ABOUT BOOST LEAKS AND HOW TO CLEAN A CONNECTION ...IT JUST GETS OLD FOR US , WHEN FOOLS WITH KNOW CLUE WHAT THE REAL PROBLEMS ARE KEEP POSTING STUPIED THINGS BEFOR YOU POST READ AND MAKE SURE YOU ARE GIVING THE RIGHT ADVICE ...THANKS

jfairladyz

come on now thats a little on the ignorant side. There are people that have been on here for years that have very little posts. A post count is no testament to ones knoweledge or how often they frequent the forum. All's it says is that a person likes to post. Pooflinginmonkey is seems to be VERY knowledgable when it comes to these cars but he has very little posts. Are you saying his input is less valuable then yours because you have over 1000 posts???

And checking connections is not stupid ****. It's the simple things that often get overlooked. How many of us have worked ourselves into a frenzy only to find out we forgot to plug something back in or it came down to a fuse that was overlooked. Stupid things are usually the cause of the problem.

And as far as "fools with no clue what the real problems are": that must be ALL of us. Otherwise Bleach would have this problem fixed already

I'm not attacking you Black... I just think that post was a little harsh. I know what you're trying to get at as we have our fair share of those who like to contribute pointless information (but dont we all )... but I just think that was a little rash.

Skully

bleach do me a favor...make something like this and pop it on the intake and put in about 5-7psi of air...seems like you still have not tested for leaks like i told you to...this way you will know FOR SURE and not have to guess....
this is what I made for my brothers car. read the instructions on what to do too it helps....just do it, dont **** me off.
http://www.boostpro.net/prodtester.html

81 Black L28E

NO it wont ...my air fuel gauges cycle shows me that the euc ajust the flow of the injector pulse for lots of things ..
the ecu will ajust the injector pulse to more or less depending on how much fuel is flowing though the rail ..if less is flowing though then i read leaner if more is going though then i read richer .
if iam driving at 55 the gauge cycles from lean to just about ideal on the gauge ..if i stomp it she will jump right to the frist rich bar AND STAY THERE UNTELL I LET IT OFF .
if i let the gas off to 1/3 of the way then she starts cycling again in the upper ideal bar ..
if its cold it will read less of every thing 55mph will read one ideal bar ..if warm she runs about three bars ...cold or hot out the ecu is alway checking and changing the air mix thats is its job ajusting for the curve..
if i turn up the psi to 35 i get one green rich bar BUT ONLY WHEN REVED OUT HARD ...
the cycle alway stays ideal when running at lower trottle speeds...showing that the ecu knows whats going on and ajust the fuel curve to whats needed..i think your does to but there isnt eff fuel there to do it with ..

J this post has been going on for so long that all of the things posted have realy been done ..and it just getts old when people post the same **** that bleach already tryed ..as for having more or less posts is more of me saying if you realy dont know that the f!@#! your talking about then dont post ...
READ FRIST..

this is a fuel problem he is running lean almost on the edge of being to lean ...it runs fine at idle but when he trys to step on it she cuts out ..ie shes sucking to much air and not putting in the right mount of fuel to it when reved...my car can get away running lean because there is no boost ie extar air being pushed into it .
a turbo can run lean at lower trottle becuase it isnt pushing the air in yet ..as you push more air in it . you need more fuel if there isnt eff flowing though the rail then your not going to push eff though the injectors..beach turn up the fuel psi !STOCK PSI SETTINGS ARE FOR STOCK RAILS ..BIGGER RAIL HOLE MEANS MORE PSI NEEDED ; )

jfairladyz

The problem is that he is clearly getting enough pressure. He's running higher then stock. On stock pressure I could boost to almost 10psi without an intercooler without it cutting out. Above that and I'd run out of fuel. He's got more then enough pressure and can't get past 4 psi. I dont think the problem lies in the "wet" portion of the fuel system. Either he's having timing issues or something is signaling that ecu to run lean. -18 is a little (numerically) low on the vacuum side... but it's not enough to cause issues. If the car will idle then I dont think a vacuum leak is the problem. A vacuum leak is more likely to cause a rich condition (on boost) in a turbo car due to the positive pressure being forced OUT of the engine by the turbo. The engine is not going to be sucking in air via vacuum leak when the engine is on boost. At idle is where a vacuum leak makes itself most evident cause the engine is sucking in extra air while its in it's vacuum state which will make it run lean. Raising Fuel pressure at this point is just a poor excuse for a bandaid and does not address the cause of the problem. And lets not forget that a car can and will stumble with too much fuel as well.

Is the BOV installed bleach??? 4 psi doesn't sound like a lot but its enough to blow out of a weak seal. That wouldn't be evident as a vacuum leak cause it's a pressure leak. Also, does it do this full time or only when the car is being driven?

jfairladyz

There in lies the problem with starting a new post on a problem thats already being addressed. I'd love to help but I'm not really going to feel like searching back through the other posts on this subject so that I can come back to this thread and then try to help. I'm going to make my responses based on what I read in THIS thread. And I've been here through the duration of this problem. There are too many people having problems here to try to remember everything that has already been recommended or tried collectively through 2-3 threads.

veyenyl

That's a pretty ignorant thing to say. If Bleach doesn't want to take someones advice he doesn't have to take it but when trying to troubleshoot a problem it helps to have other people brainstorming with you.

As far as a bigger rail needing a more psi thats not really true. If his fuel pressure gauge is reading 35psi, thats whats the injectors are seeing regardless if he's running stock or a JSK rail.

Maybe you should take you own advice and read first. He's at 35psi which is exactly what you are running.

silvrhand

Oh god..

Please go away with that, first off turn off the caps, sit down and relax. Everyone is here to help, and sometimes the simple things you forget to check. Don't get all snippity just cause you have xxx amount of posts, there are people here that don't know jack and have more posts.

Skully

all i want...is for him...to do ..that leak test....thats all...and if he does...i wont post here anymore...just please....please....do it....for the love of god...do it.

81 Black L28E

YOU SHOULD F#$% OFF YOUR SO WRONG . .do you have a jsk rail ? HAVE YOU EVER OWNED ONE .DO YOU EVEN KNOW WHAT RICH OR LEAN MEANS .DO YOU KNOW ANYTHING ABOUT THESE CARS NEWBE ..YA I DIDNT THINK SO .**** OFF


I WILL BETT $100 DOLLARS IF YOU PUT MY FPR ON YOUR MOTOR BLEACH AND THEN TURN IT UP TO 37PSI SO THAT WHEN REVED I HITS ABOUT THE 42PSI MARK THEN TAKE IT FOR A RUN ALL OF THE PROBLEMS WILL BE GONE !!

j REMBER WHEN MY CAR WOULDNT RUN ..I LEARNED ALL ABOUT FUELING THESE CARS..
TRUST OLD BLACK ..I AM RIGHT !