# 1996 HB Cutting in & Out



## WACKYDAC (Nov 9, 2014)

My 1996 HB is cutting in & Out but only at a particular position on pedal travel. Lets say you hold it at 20mph in 2nd gear. The truck will just cut in and out. Hold it at 15mph and it will run all day. It accelerates fine it's only when you get back to that 1/8 travel on the pedal that it cuts out.
Engine code reads problem with TPS System. Replaced TPS problem still the same. This truck was in the shop in June 2013 had new TPS,IAC,& MAF
$ 1000.00. Ran fine till Sept. 2014. It has only been driven less than a thousand miles since being worked on. I put the old TPS back on and truck does same thing. It did not go to shop for this problem in 2013 it was a totally different problem. It was intermittent and had to be taken back three times and had to be doing it's thing at the time of reading. It turned out to be the MAF.


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## smj999smj (Jan 1, 2006)

Since it threw the TPS code, did anyone bother to do the diagnostic per the service manual for the code, such as checking the wiring circuit, or did they just throw the part in? Trouble codes aren't intended to tell what the bad part is, they are intended to give a direction to diagnose the problem. It's the service manual diagnostic procedure for that particular code that is intended to isolate the exact cause of the problem that caused the code to set.


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## WACKYDAC (Nov 9, 2014)

A new part was not thrown in. A new TPS was installed in June 2013 along with a new IAC and a new MAF. It was all diagnosed at the shop. At that time it was a different problem and a bad MAF was diagnosed. I had them put in a new TPS and a new IAC also. It was all set up to specs and the truck ran fine until Sept 2014 when it put out the TPS code.
I had the old TPS so I installed it to see if it made a difference. It still did the same thing. I'm going to put the new one back on and take it to the shop. I'm just trying to pick a brain because it took three times to the shop last time and each time I took it in the truck wouldn't mess up so they couldn't diagnose it until it did it and I pulled it in with no appointment. They ran out hooked up and found the MAF problem.


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## jp2code (Jun 2, 2011)

Sounds like a bad electrical connection to one of those sensors.

That could be from corrosion (you'll get a lot of it after 20 years), wires that have frayed, or grounds that are not making good contact.

Difficult for a shop to troubleshoot, because they are just geared towards replacing parts.


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## WACKYDAC (Nov 9, 2014)

Thanks JP. I'm thinking in the same direction. The last time I visited at least five shops and told them the problem most of them wouldn't even take the job. It's a desert truck so very little to no corrosion. Even the muffler bolts just come right out. One of the advantages of bearing with 110 degree summers. I do think it's in the wiring though.
Since on board computers you can hardly touch anything without a $4000 piece of equipment. I'm about to take it to the shop. I put the new TPS back on. I'm hoping they can find it with one shot.
THANKS FOR YOUR POST.


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## jp2code (Jun 2, 2011)

You've got the free service manuals, right?

They have steps to follow with pictures in the EL section.

It is a lot to repost, and difficult to understand without the pics.

If you can find a guy who used to work at Nissan, that's the one to visit. He'll be used to searching these things by the manual. Craigslist sometimes has local mechanics who post that they worked for Nissan.


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## smj999smj (Jan 1, 2006)

If you can duplicate the problem, grab the engine harness near where it runs from the firewall and along the intake manifold side of the valve cover and move it around to see if it corrects the problem or makes it run differently. I've never seen it occur on a 96/97 model, but I have seen it occur on several 95 KA24E Hardbodies, where the wiring splice crimps can loosen and create a poor connection. One of those crimps is a ground wire splice for several engine management components including the MAS and TPS (I can't remember if the IAC was one of them, but might be). The fix was to cut open the engine wiring harness conduit and electrical tape holding the wires together in the area from the rear of the valve cover to about half-way forward. You'll see several splice connections of black wires that have a small piece of electrical tape around them. Remove the tape and clean the splice crimp connection with some brake cleaner or electrical cleaner to get the adhesive from the tape off. With a solder gun and some resin-core solder, solder all of the crimp splice connections. Wrap them with a small piece of electrical tape and re-wrap the harness and conduit. There was a bulletin put out in 95 or 96 that described the procedure and condition, but I can't find it. It sounds like it may be what's going on.


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## WACKYDAC (Nov 9, 2014)

*!996 HB*

Thanks SMJ:
I'm thinking in that direction also that's why I'm putting off the shop. I just don't think they will take the time.
I cheeked the volts per specs from the power wire to the TPS and it's not right. I can't get any more than two and moving the TPS from left to right does not change it like it's supposed to. I'm going to check those wires and the connector.
Thanks for the help.
Wackydac.


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## Shook (Nov 17, 2018)

*1992 HB cuts out at 2k rpm*

I realize that this is a 4 year old thread, but my 92 HB is doing the exact same thing to the T. I purchased the truck with a rough idle, threw some parts at it with no positive result. Pulled the throttle body off of my running 95 HD and bolted right on to the ‘92. And that is when I encountered the exact problem that WACKYDAC has described. The only difference bewtween the two throttle body’s is that the TPS has a slight redesign. Same connector though. So I then put the ECU from the ‘95 onto the ‘92. No change. Both ECU’s show the throttle sensor circuit to be the issue. Code 43 if you are counting the blinking lights. I was about to check the wiring from the TPS harness back to the ECU when I happened across this thread. Has anyone pin pointed the cause of this issue? By the way, the ‘92 HB is a 82k mile survivor, while the ‘95 is going strong at 289k. Hopefully someone will see this thread ?


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## jp2code (Jun 2, 2011)

My guess is the TPS on WACKYDAC's throttle body was either messed up or some of the wiring going to the TPS was having a grounding issue.

[VIDEO] Checking Error Codes - Infamous Nissan - Hardbody / Frontier Forums

43 Throttle Position Sensor Circuit (Check Engine Light item)

Throttle sensor circuit is open or short (output voltage is too high or too low).

EF & EC-280: 

Turn ignition switch "ON". Voltage between TPS terminal C and Ground should be 5V.
Turn ignition switch "OFF". Continuity should exist between TPS terminal A and Ground.
Disconnect ECU harness, verify continuity exists between ECU terminal 20 and TPS terminal B.

Repair anything that isn't right.

Check Throttle Sensor, EF & EC-316:


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## rogoman (Dec 16, 2004)

Here's something that relates to SMJ's previous posting:

FIX: erratic idle, low speed driveability, possibly more - Infamous Nissan - Hardbody / Frontier Forums


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## 1997pickup (Mar 20, 2019)

check EGR ports and ERG valve and ERG bypass valve
only 15 years late


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## rogoman (Dec 16, 2004)

Why bother replying this late. You're just taking up useless space on the forum. Stick with new threads to reply to. He probably either fixed it or sold it.


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