Hesitation during acceleration

[DC871F]

Testing TPS. Continuity checks good at the TPS, Idle and full throttle. but at the ECU plug test as set forth by AFM, I get nothing. PIN's are PIN's correct, I dont need a year specific test for the 82 do I?

Tried the clamp method on the return fuel line, no change.

Did notice if I moderate the gas pedal (wiggle my foot) up towards full throttle, it does "seem" like it wants to accelerate smooth, but it may be my imagination. This was done without the clamp.

All this done with the advance plugged.

[DC871F]

On 1/2/2018 at 7:54 PM, madkaw said:

might think about putting a fuel pressure gauge on there to see what’s going on . I had a zxt that was giving me a fits and it was a clogged return line. Showed almost 100 psi at one point - don’t know how things didn’t explode -

I went through fuel system, but it could be that something dislodged. Car sat for many years, and fuel system was completely taken apart. Only thing original are the fuel lines under the car, which I blew out pretty good with air and gas.

[DC871F]

On 12/28/2017 at 12:46 PM, siteunseen said:

The easy way to "kinda" test for lean I learned from a Nissan certified mechanic.  He put some taped up vise grips on the return line to build more pressure and my car ran better.  He didn't know about the "tweak" and said I needed a new FPR or pump or injectors...blah, blah, blah.

$5 dollars at Radio Shack and 30 minutes later it ran better than ever.

But I would think, just for smog test not everyday driving, you could lean one out the same as make one richer.  I know I played with mine for months while driving.  I could change the Temp, gas mileage and how it ran up top and from take off.  It was fun for awhile. 

Did the clamp trick, no change. I got the resister in from ZDepot, but will hold off an that until I do more testing.

[siteunseen]

Have you popped the black cover off the AFM to make the sweeper vane is free and the contact surface clean?  Just a thought.  You may not want to remove it, mine is held on with zip-ties.  One day I'll silicone back down.

Another question I thought about, sitting still will it rev up & down like normal?  Does it just hesitate under load?  If the AfFM vane is messy it won't rev up.

[DC871F]

32 minutes ago, siteunseen said:

Have you popped the black cover off the AFM to make the sweeper vane is free and the contact surface clean?  Just a thought.  You may not want to remove it, mine is held on with zip-ties.  One day I'll silicone back down.

Another question I thought about, sitting still will it rev up & down like normal?  Does it just hesitate under load?  If the AfFM vane is messy it won't rev up.

Only under load. 

I have not looked under the AFM cap, might go out now and do that. When I mentioned AFM before in my last post, I meant FSM. I use AFM at work, so I just flowed out.

The AFM is under constant motion right, always making corrections. I was thinking it was something that was consistent, no what I mean?

[DC871F]

Forgot to add, I couldnt get a the TPS insulator check to pass either out on the TPS sensor. So I guess the TPS is bad.

AFM is clean and shinny like its 1982.

[Zed Head]

2 hours ago, DC871F said:

Testing TPS. Continuity checks good at the TPS, Idle and full throttle. but at the ECU plug test as set forth by AFM, I get nothing. PIN's are PIN's correct, I dont need a year specific test for the 82 do I?

Here you said the TVS (not really TPS) is good.  Here's the 82 procedure.  It's on page 82.  Too.

[madkaw]

2 hours ago, DC871F said:

I went through fuel system, but it could be that something dislodged. Car sat for many years, and fuel system was completely taken apart. Only thing original are the fuel lines under the car, which I blew out pretty good with air and gas.

Without putting a gauge in there - you still are guessing . 

[DC871F]

2 hours ago, madkaw said:

Without putting a gauge in there - you still are guessing . 

Yes, have wait till I get a gauge, until then I'll look other places. Aftermarket pump installed with the rest of the fuel system components.

 

[DC871F]

2 hours ago, madkaw said:

Without putting a gauge in there - you still are guessing . 

 

2 hours ago, Zed Head said:

Here you said the TVS (not really TPS) is good.  Here's the 82 procedure.  It's on page 82.  Too.

Did the procedure on p.82. For some reason its not testing through the ECU plug. Testing the TVS directly I get continuity on the idle and full open throttle. I do not get a good test on the insulation test. When testing through the ECU plug, do you need a ground jumper?

Thanks.

[Zed Head]

If the ECU doesn't see it it doesn't count.  Trace the wires from the ECU to the TVS, it's easier than it seems. Most of the engine's electronic components are on sub-harnesses with bullet connectors tying in to the main harness to the ECU.  Maybe yours are disconnected.  "Full throttle" is actually about 75% throttle opening or something like that so it could be a factor.  The ECU adds a lot of extra fuel at "full" throttle.  " "  "  "  "

The ECU plug has its own grounds.  The FSM tests are explicit, nothing needs to be added.  Place the probes and read the meter.

Edited January 5, 2018 by Zed Head

[DC871F]

41 minutes ago, Zed Head said:

If the ECU doesn't see it it doesn't count.  Trace the wires from the ECU to the TVS, it's easier than it seems. Most of the engine's electronic components are on sub-harnesses with bullet connectors tying in to the main harness to the ECU.  Maybe yours are disconnected.  "Full throttle" is actually about 75% throttle opening or something like that so it could be a factor.  The ECU adds a lot of extra fuel at "full" throttle.  " "  "  "  "

The ECU plug has its own grounds.  The FSM tests are explicit, nothing needs to be added.  Place the probes and read the meter.

Yeah, disregard, had the TVS disconnected, so.......

Its 25 degrees tonight in N.FLA, been back and forth between fire place and garage, forgot to hook the TVS back up. So at least I dont have to chase wires tonight.

So if the TVS does not pass the insulation test, I'll at least need to replace. Would this cause my issue?