1986 nissanzx doesnt let me go over 3000rpm

[Steph]

my 1986 300zx starts fine but when i step on the gas pedal it goes up to about 3000 rmps and then drops againalwaysit makes the car jump when i start to drive itits an automatic...everything in the engine is fine...we changed the sparkwires and sparkplugs ...altenator works fine toowhat could it besomeone told me to check the air sensor or something but i dont know where that might beplease help as soon as possiblethanks Steph

[Und3rprshUr]

Its. your AFM mass air sensor. it is located on driver side fender follow the air filter till you see a big round sensor.with a plug going into it. where are you located. i have one for sale. (AFM)

[Steph]

thanks...gonna check that out on the weekend if it wasnt that maybe you could help me more thenim in new jersey but dont really need another one i still have my old one where i just get parts out of itbut thanks anywaySteph

[Steph]

i checked out the amf and changed it ...that wasnt the problem...even checked the timing...what else could it be...any kind of fuses or something...or relays?

[Und3rprshUr]

tps would be next.. but should have been the afm did you replace it with a new one or used.? i have replaced some with used but they were also bad.

tps could be bad.. try pulling the codes in the ecu.

[Steph]

ok i cant figure this thing out it has to be some kind of god damn computer...what is a tps and what do you mean by pulling the codes in the ecu...and what are the chances that its the intake manafold having a leak...i have a parts car for it so there is no problem getting things for it i just really need to know what it is that could be causing the problem...

[Und3rprshUr]

Tps sensor is on the right side of the throttle body. unplug it and see fi car acts diff . then let me knwo.

Do you have a Haynes manual for the car ?

[Steph]

i already changed that thing too but nothing is different....

[Und3rprshUr]

Do you have a aol screen name ? or msn ?

[Steph]

yeah message me at the1andonlyjmc or snuggle1410

[Steph]

whats your aol name???? i can message you

[U12 2NR]

if it's not the AFM then it's an air leak somewhere.

[Und3rprshUr]

ZUnd3rprshur my aohell name

[Steph]

alrightnow i adjusted the tps and erased the memory on the ecu ... nothing new happened besides that the ecu gives me the code 44 and that means that its working properly right?might there be something else wrong with my god damn carconnections to the amf are clean and why would the harness be damaged?well would check that out but dont know where that is and how to find itcould there be something wrong with the fuel pump or the fuel injectors or something?i really dont know what to look for anymore

[U12 2NR]

yes code 44 means everything is okay. What you should do is check the stock intake. Make sure all the vacuum lines (large and small) that run off the main intake tube are all in tact and not loose or anything. There's one big one that runs to the fuel rail that will cause the problem you described. There are vacuum lines hidden under the intake tube, so make sure you check it out thoroughly.

[Steph]

what exactly is the stock intake and where is itthat one big one that could cause the problem...where is that exactly?...i dont know where the fuel rail ismaybe if you have a picture of that ...that would helpthanksSteph

[Bizz]

Ok I am having the same problem on my 85 200sx turbo..... replaced the TPS to no avail. Checked the MAS and it's giving me the right Ohms resistance. I'm gonna check for vaccum leaks, but i already tried once with starting fluid and found none.

[Bizz]

more info on my problem (sorry for the thread jacking) I have to use starting fluid to get it to start about 75% of the time. Also if I let it warm up it won't start afterwards. Seems to act like it's running rich. Sputter sputter, smells rich and starting fluid kills it. Do you think it's the same problem steph is having? How did your problem start steph?

[Und3rprshUr]

o.k. boys after doing some research optical sensor LED ignition systems(LED crank angle sensor) used on many diffrent nissan models is extremly common for failure and cut out and or stop working when engine reches operating temp. Only cure woul;d be to purchase a new distributor or go to junk yard and rip one apart and get one it is in the distributor.

Hope this is your problems. Might not be

[Bizz]

Yeah I replaced that as well.

[Und3rprshUr]

BiZZ try Z31.com tons of info there and experienced ppl on the message board.. your motor is the same as in a Z31 (84-89-300zx)

[Bizz]

I actually have the turbo 4 (ca18et), but I do share a lot of components with the z's of the same generation.

[Steph]

i dont know how it started..i just go the car and it did itright now im just asking everybody if they could know what it is...i didnt check the ohms on the mas yet though...so maybe my problem is still that god damn thing...i replaced it thoughwill chek out the crank angle sensor and or distributor and see what happenes...thanksSteph