# 1986 nissan d21 runs fine but surges power at 2500 rpms or wen on a load. please help



## provalvemx45 (Jul 29, 2010)

i have a 1986 nissan pickup my motor blew on the original motor i had in it wich was a 720. now replaced it with a d21. everything runs fine until i go up a hill or mash the gas kinda hard. it starts to have this surging power all the way up the hills, but as soon as i get to the top of hills it just opens up and runs fine. ive replaced both coils, plugs, cap, rotor, wires, no vacuum leaks. just cant seem to figure it out. i do have a tiny little hole in my distributor cap. could this be the problem??? ive checked the timing also and it is right on point. could it be a tooth off that is causing this problem.
by the way its a 2.4l automatic.
any info would be much appreciated!!!!


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## zanegrey (Dec 5, 2005)

read the sticky and read the codes...


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## provalvemx45 (Jul 29, 2010)

dont mean to sound like a retard but wats the sticky? and i have no idea where to plug in the reader for the codes?


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## GeoBMX4Life (Mar 25, 2010)

*Sticky's are at the top of the HB Truck forum*



provalvemx45 said:


> dont mean to sound like a retard but wats the sticky? and i have no idea where to plug in the reader for the codes?


 Here's the link if you honestly can't find the sticky...and after you read it, you will learn that these trucks don't need a code reader.
http://www.nissanforums.com/hb-truck/140369-how-check-your-ecu-error-codes.html


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## GeoBMX4Life (Mar 25, 2010)

*Sticky's are at the top of the HB Truck forum*



provalvemx45 said:


> dont mean to sound like a retard but wats the sticky? and i have no idea where to plug in the reader for the codes?


 Here's the link if you honestly can't find the sticky...and after you read it, you will learn that these trucks don't need a code reader.
http://www.nissanforums.com/hb-truck/140369-how-check-your-ecu-error-codes.html


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## zanegrey (Dec 5, 2005)

WHAT DID THE ALIEN SAY TO THE NISSAN TRUCK ???


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## zanegrey (Dec 5, 2005)

TAKE ME TO YOUR READER.....


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## zanegrey (Dec 5, 2005)

I DON'T CARE WHO YOU ARE ...THAT WAS FUNNY...


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## GeoBMX4Life (Mar 25, 2010)

*LMFAO!!!!*



zanegrey said:


> WHAT DID THE ALIEN SAY TO THE NISSAN TRUCK ???


 Here are a few things...I can't read...please help.
I'm REALLY new at this
Please be patient with me!!!
I hope ZaneGrey doesn't read this...i'm sensitive!!!
LOL...give the kid a break ZG...I do however appreciate you humour and sarcasm...


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## provalvemx45 (Jul 29, 2010)

thank you!!


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## provalvemx45 (Jul 29, 2010)

didnt work. that sticky is for a pathfinder. my box under my seat doesnt have the screw to turn clockwise and wat not. gonna try and find the one for my year. and my bad i meant to say its an 1985.


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## zanegrey (Dec 5, 2005)

ok,
your truck is a 720 with a carb..

if you have an ecm then u can still check it.

with the key to the on position but the engine not running check the ecm lights to see if they are on.

then flip the switch to on.

when the lights blink they will blink 1 time then twice then three times then four times then 5 times..

those are the modes.

turn the switch off when it blinks three times..

three blinks ies the stored trouble codes..

then record the codes..

since you have a carb , check the vacumn to the choke and dizzy...


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## zanegrey (Dec 5, 2005)

check this site out as well ..

and talk to datzen mike...

720World


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## provalvemx45 (Jul 29, 2010)

alright cool im gonna give that a try right now. ya im on that website site as well ive been talking to datzen mike for a little while he has been pretty helpful. im also gonna change out the fuel pump cause i just took it apart and cleaned the filter inside it and i ran good for about five minutes then started doing the surging thing again. ill keep u updated on it though. and i really appreciate ur guys help its helped me out alot!!!!


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## provalvemx45 (Jul 29, 2010)

ok i tried that but i dont have a switch on my ecm. wen i turn the key to the on position the light just stays green doesnt flash at all. wen i start it it turns off???


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## zanegrey (Dec 5, 2005)

i do not remember if the 720 is readable..or if it has a switch . but the switch would be on the opposite side of the light..

did u chack the vacumn to the choke and dizzy ??


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## provalvemx45 (Jul 29, 2010)

yeah there both good.....


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## zanegrey (Dec 5, 2005)

check to make sure choke is opening fully...


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