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1983 turbo woes


1badeagle

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Ok guys so i got some issues with my car and i need some help. Mods are intake mods, no cat. Car has 240k on it and has been rebuilt

 

-When i start my car in the morning or after it has sat all day at work. It has to crank an excessive amount before starting.(5-7 seconds) Once it starts it idles funny for a few second then its ok. Any ideas?

 

-When i start my car and take off if i floor it within the first few minutes of starting, it spits and sputters and wont go anywhere and has no power at all.Any clues?

 

-When I get on the throttle hard it pulls ok up to about 4300 rpm then it wont gain anymore speed until i shift. Is it running out of fuel? Whats wrong here?

 

-Sometimes, more often than not, the motor wil tick. It will sometimes be louder than others and it will sometimes go away when the motor is reved up. It sounds like its coming from the front of the motor when i listen with a stethiscope. But i cant pinpoint it cause its coming from everypoint. Any ideas?

 

I never noticed these issues when i first got the car a few months ago. It seems as thought they progressively have gotten worse.

 

Thanks alot,

 

Dustin

Edited by 1badeagle
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dude why is everyone all of a sudden getting my same issue!!! Lets all try and figure this out!!

 

Mine dose the exact same thing. Even before my 300zxt ECU swap and still dose it to this day!

 

Im thinking TPS (throttle position sensor)

 

When I start in morning starts ok but boggs a bit gotta give it some gas to get her to idle.. then occasionally at start when I go to drive it boggs right out and puffs and sputters then all of a sudden VROOM takes off.. anyone else got Ideas! I guess I could find a temp sensor and replace my tps now that I have another 240sx throttle body....

 

I rewired everythign today soooooo still clueless...

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dude why is everyone all of a sudden getting my same issue!!! Lets all try and figure this out!!

 

Mine dose the exact same thing. Even before my 300zxt ECU swap and still dose it to this day!

 

Im thinking TPS (throttle position sensor)

 

When I start in morning starts ok but boggs a bit gotta give it some gas to get her to idle.. then occasionally at start when I go to drive it boggs right out and puffs and sputters then all of a sudden VROOM takes off.. anyone else got Ideas! I guess I could find a temp sensor and replace my tps now that I have another 240sx throttle body....

 

I rewired everythign today soooooo still clueless...

 

Well like i said before make sure about your connections and yes i would replace the water temp sensor. I had every problem 1badeagle described except for the power loss in my 280z, I cleaned ever connection and replaced the thermo time switch and water temp sensor and i never had a cold start problem again.

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Yeah I just put an entirely new 240sx throttle body on with another TPS reset ignition timing and checked all connections, Rewired anything that looked fishy, put in another O2 sensor and now am doing plugs and oil change.. then I guess its temp sensor time Cause after that i have replaced almost everything except that little round thing beside coil whats it calld again.. Stores charge or something? all I know is when its not grounded the car wont start lol. So other than the temp sensor and that thingy everythings replaced..

 

Even used the guts of a 300zx Distributor and inserted in my 280zxt SHell and that didnt cure it either!...

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Um, look at the FSM... Neither the water temp sensor nor the thermotime switch have anything to do with EFI on an L28ET. They don't connect to the ECU...

 

The water temp sensor (yellow) goes to the gauge in the cockpit. The thermotime switch just runs the injector fan (after the car stops running IF the water temp is over 2xx degrees (sorry, can't remember the exact temp))

 

The temp sensor connected to the ECU is the Cylinder Head Temperature Sensor on the oil filter side of the engine.

 

The TPS only shows "throttle closed" (no throttle) OR "throttle not closed" (you've stepped on the pedal). It doesn't show "amount of throttle" (the switch can't show 1/4 throttle, 1/2 throttle, etc...) or WOT (which it can... that function just isn't used by the L28ET ECU)

 

My bet would be: wiring, electrical connectors, vacuum (including VCM and/or the 2 things it controls: AAC and EGR)

 

(In a stock ZXT, the VCM is mounted opposite the AFM on the same bracket)

L28ET ECCS_thumb.jpg

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ok heres my build.

 

Thing is... I have it down to a Coil/Distribution of Spark problem. or if the Cylinder Head temp sensor if it would cause Bogging at stoplight Acceleration or half throttle area (maybe most engine vibration)

 

its very strange because...

 

I have eliminated all AAC/EGR ect ect my intake is as follows.

 

Filter on end of MAF ---> Turbo ---> intercooler (just over the weekend) ---> Throttle Body (240sx) ---> intake plenum ----> combustion chamber ----> Exhaust (O2)......

 

So what are your thoguhts..

 

ECU (swapped to 300zxt 1987)

MAF (maxima 1992)

TB (240sx 60mm)

Stock 280zxt injection

Stock sensors

TPS 1990 Maxima

Converted to Cable throttle

Ported head intake to 32.55mm (from I think stock was 28.5mm) so to *gasket match*

1987 300zxt turbo mated to 280ZXT wastegate and downpipe

280zxt Wastegate actuator (1981.5 stock)

Swapped in and out MFPR and Stock FPR no change

tried different fuel ranging PSI from 32psi to 50Psi

Switched out distrubutor internals with 300zx and same symptoms

Soooo

 

this problem was happening before my swap to ECU Z31T so I was hoping the change would cure it with better mapping ect ect but to no avail.

 

its almost like I have an injector stuck open but when I check plugs they are all slightly blackend with soot so its as if its misfiring on all cylinders intermitantly or just over fueling every so often...

 

any ideas greatly appreciated.. I should test the Head temp sensor I guess.. Anyone know resistance values or I guess I can look it up on ALLDATA.

 

after that if that is all good. then I guess im looking to buy a New Cap and or Coil assembly

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Ok guys, i pulled the valve cover off to check the valves and noticed that on the drivers side of the timing chain it is incredibly loose. Is this normal? I see a rebuild by me in the future. Also is it me or do you need some kind of special tool to run the valves on this thing?

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  • 4 weeks later...

 

-When i start my car and take off if i floor it within the first few minutes of starting, it spits and sputters and wont go anywhere and has no power at all.Any clues?

 

 

I have this same issue in my 83 ZXT w/160k (has not been rebuilt), and the bogging problem does seem to disappear when the engine reaches full operating temp. Did notice this problem after I ran Seafoam in the car (crankcase, gas tank, and intake), I thought my fuel filter was clogged from the Seafoam in the tank and replaced it but the problem remains and it only occurs while cold. Im thinking maybe a clogged Cat, because the spark plugs are oily (prob worn piston rings), and the car is misfiring sometimes, which could cause unburnt fuel to enter the cat and melt the components. I guess is: 1. Clogged cat (goes away when car warms up and cat heats up) 2. Engine Temp Sensor. 3. Clogged Fuel Injectors

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Sounds like a vacum leak. When I bought my car, it did all the same things. I changed the plugs, wires and distributor cap and changed all the vacum hoses 1 at a time until the problem went away.

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