# Bucking and jerking at low RPM



## screamn demon (Sep 6, 2010)

Alrite fellas im new to this site and nissans. Ive read a lot of posts on these HB nissans bucking, jerking, stalling, and surging but none seem to match exactly what my 93' 2.4 5 speed 4x4 is doing. Upon start up the truck will idle extemely ruff and very high at an unknown RPM because the tach doesnt work. The truck will continue to stay there unless I unplug the IACV. Upon take off the truck sputters and begins bucking like a bronco until i go above a certain RPM approx. mid pedal. When driving at any speed and gear when you take your foot off the pedal the truck immedaitly bogs down. When you get back on it there is a slight hesitation before it will pick back up. I can manually move the throttle lever and when at gets mid throttle the truck will start surging until i pass that certain spot. Ive replaced the plugs and wires so far and cleaned/ inspected the MAF. I believe its the IACV but I wanted yalls opinions first before I take it out. Thanks for any help in advance Brandon


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## GeoBMX4Life (Mar 25, 2010)

Have you read the codes?


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## screamn demon (Sep 6, 2010)

yeah i pulled the codes and it showed the MAF and temp gauge in Intake. I cleaned both and cleared codes. Now it shows nothing


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## GeoBMX4Life (Mar 25, 2010)

I would check for vacuum leaks next.


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## screamn demon (Sep 6, 2010)

i forgot to mention i did that to with carb cleaner and a vacuum test at my buddies shop. Only found one 3 inch long hose that was melted on the back side of the EGR valve.


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## GeoBMX4Life (Mar 25, 2010)

It sounds like the MAF, or TPS...you can take then MAF off, and physically see if the diodes are intact or not. I just went thru something similar to this, last spring, 1 of the 2 wires/diodes were broken, but sometimes making contact...so the codes came back clear...and when they weren't making contact, I was getting the MAF code.


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## screamn demon (Sep 6, 2010)

ok the diodes looked intact when i cleaned it but like you said they might not be making contact. i was extremely careful with them but i will take another look and post back. thanks


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## GeoBMX4Life (Mar 25, 2010)

Using a multi meter, you can check the continuity at the plug in.


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## screamn demon (Sep 6, 2010)

alrite i cleaned the MAF and the everything checked out with the multimeter. So then i the checked codes. In mode 3 i got MAF, TPS, and intake air temp sensor. So i cleared them out and drove it around and the only code i get now is 43 TPS circuit. I did the test for it in mode 4 by turning the key to start and pressing the gas. I was supposed to see the red LED come on but it didnt. Im guessing the TPS is the problem. How can i check for proper adjustment before i go by a new one thanks.


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## GeoBMX4Life (Mar 25, 2010)

Undo the side mount screws, and go up or down a little bit at a time on each side, you'll notice instantly when you start and idle the truck. If the TPS is shot, it won't make a diff when you move it. I'm sure that Zanegrey has these for sale...just PM him.


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## screamn demon (Sep 6, 2010)

ok thanks for the help


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