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[Dave Moore]

92 Nissan PU 2.4 Litre/146 cubic inch OHC , 4 cyl , Elect Multi-PT fuel injection
feedback fuel system, catalytic converter


Crikey,
My mechanics have changed out the computer module,
the throttle sensor and also some kind of air sensor
all supposedly related to a fuel injection problem

They also, replaced the timing chain, worn but not
totally kaput yet. ( approx 110,000 miles )


My wife say's it lugs down at high speeds when
you hit the accelerator

I noticed while it's idling, when I advance
the accelerator ( in neutral ) at some point
the engine seems to throttle excessively.

In other words, the acceleration of the motor doesn't seem
to track the gas pedals position linearly, but maybe this is
normal for an unloaded engine,, dunno.

I guess it should be mentioned that the mechanics put
in "used" parts salvaged off of another truck which had
been rear ended. We don't use this truck nearly as much as
a lot of people might, so I am thinking, perhaps the parts
they put in might be as worn out or even worse than the
originals.

I guess the question is,,, does this seem like a familiar problem?

If so, rather than trouble someone to re-post old news,
what then might be good keywords to use in a google search
of the archives of this newgroup for previous discussions
about this problem?

PS. another question. I have a degree in electronics and
am experienced in componentl level debugging of microprocessor
based systems. So, I'm not intimidated by the electronics of the
fuel injection system, however, as knowledgeable as one might
be in this field, troubleshooting such circuits are a major ordeal
unless decent service literature can be obtained

So, the last question is,, what kind of service literature can I expect
to find in this regard? I'm guessing that the microprocessor module
is going to be treated pretty much as a "black box" with little or no
information as to what's inside it,, right?

Thanks very much
But even more, thanks from my wife
who is at wits end needing her truck.

--Dave--

[Al's]

could it perhaps be the in gas tank fuel pump. I had similar problems with a
vehicle once and that's how it acted prior to failure. Also have a good look
at the neutral safety switch. if its failing it maybe messing up the torque
converter. I am no mechanic but those are the things I would check other
then the fuel pump pressure and filter ( the one on the bottom of the fuel
pump, not the one in the gas line) not used much so perhaps it also could be
dirt/ water in the gas tank
Hope it works out for you
Al
"Dave Moore" <novalves@NOT*ED*.bellsouth.net> wrote in message
news:UjAjd.37552$Om6.25238@bignews5.bellsouth.net...

[Meat Plow]

On Sun, 07 Nov 2004 19:33:49 -0600, Dave Moore wrote:

[doS]

Did ya bother to have the fuel injectors cleaned?

"Dave Moore" <novalves@NOT*ED*.bellsouth.net> wrote in message
news:UjAjd.37552$Om6.25238@bignews5.bellsouth.net...

[Steve T]

Dave Moore wrote:

[Dave Moore]

thanks,
I'll check into those things


"Al's" <allanromansnospamplease@accesswave.ca> wrote in message news:maJjd.126495$df2.72792@edtnps89...
: could it perhaps be the in gas tank fuel pump. I had similar problems with a
: vehicle once and that's how it acted prior to failure. Also have a good look
: at the neutral safety switch. if its failing it maybe messing up the torque
: converter. I am no mechanic but those are the things I would check other
: then the fuel pump pressure and filter ( the one on the bottom of the fuel
: pump, not the one in the gas line) not used much so perhaps it also could be
: dirt/ water in the gas tank
: Hope it works out for you
: Al
: "Dave Moore" <novalves@NOT*ED*.bellsouth.net> wrote in message
: news:UjAjd.37552$Om6.25238@bignews5.bellsouth.net...
: > 92 Nissan PU 2.4 Litre/146 cubic inch OHC , 4 cyl , Elect Multi-PT fuel
: injection
: > feedback fuel system, catalytic converter
: >
: >
: > Crikey,
: > My mechanics have changed out the computer module,
: > the throttle sensor and also some kind of air sensor
: > all supposedly related to a fuel injection problem
: >
: > They also, replaced the timing chain, worn but not
: > totally kaput yet. ( approx 110,000 miles )
: >
: >
: > My wife say's it lugs down at high speeds when
: > you hit the accelerator
: >
: > I noticed while it's idling, when I advance
: > the accelerator ( in neutral ) at some point
: > the engine seems to throttle excessively.
: >
: > In other words, the acceleration of the motor doesn't seem
: > to track the gas pedals position linearly, but maybe this is
: > normal for an unloaded engine,, dunno.
: >
: > I guess it should be mentioned that the mechanics put
: > in "used" parts salvaged off of another truck which had
: > been rear ended. We don't use this truck nearly as much as
: > a lot of people might, so I am thinking, perhaps the parts
: > they put in might be as worn out or even worse than the
: > originals.
: >
: > I guess the question is,,, does this seem like a familiar problem?
: >
: > If so, rather than trouble someone to re-post old news,
: > what then might be good keywords to use in a google search
: > of the archives of this newgroup for previous discussions
: > about this problem?
: >
: > PS. another question. I have a degree in electronics and
: > am experienced in componentl level debugging of microprocessor
: > based systems. So, I'm not intimidated by the electronics of the
: > fuel injection system, however, as knowledgeable as one might
: > be in this field, troubleshooting such circuits are a major ordeal
: > unless decent service literature can be obtained
: >
: > So, the last question is,, what kind of service literature can I
: expect
: > to find in this regard? I'm guessing that the microprocessor
: module
: > is going to be treated pretty much as a "black box" with little
: or no
: > information as to what's inside it,, right?
: >
: > Thanks very much
: > But even more, thanks from my wife
: > who is at wits end needing her truck.
: >
: > --Dave--
: >
: >
:
:

[Dave Moore]

Not sure, I'll ask the mechanics whether they did that.
thanks

"doS" <kobo65@notSOHOTmail.com> wrote in message news:10ovvrdbihni1f@corp.supernews.com...
: Did ya bother to have the fuel injectors cleaned?
:
: "Dave Moore" <novalves@NOT*ED*.bellsouth.net> wrote in message
: news:UjAjd.37552$Om6.25238@bignews5.bellsouth.net...
: > 92 Nissan PU 2.4 Litre/146 cubic inch OHC , 4 cyl , Elect Multi-PT fuel
: injection
: > feedback fuel system, catalytic converter
: >
: >
: > Crikey,
: > My mechanics have changed out the computer module,
: > the throttle sensor and also some kind of air sensor
: > all supposedly related to a fuel injection problem
: >
: > They also, replaced the timing chain, worn but not
: > totally kaput yet. ( approx 110,000 miles )
: >
: >
: > My wife say's it lugs down at high speeds when
: > you hit the accelerator
: >
: > I noticed while it's idling, when I advance
: > the accelerator ( in neutral ) at some point
: > the engine seems to throttle excessively.
: >
: > In other words, the acceleration of the motor doesn't seem
: > to track the gas pedals position linearly, but maybe this is
: > normal for an unloaded engine,, dunno.
: >
: > I guess it should be mentioned that the mechanics put
: > in "used" parts salvaged off of another truck which had
: > been rear ended. We don't use this truck nearly as much as
: > a lot of people might, so I am thinking, perhaps the parts
: > they put in might be as worn out or even worse than the
: > originals.
: >
: > I guess the question is,,, does this seem like a familiar problem?
: >
: > If so, rather than trouble someone to re-post old news,
: > what then might be good keywords to use in a google search
: > of the archives of this newgroup for previous discussions
: > about this problem?
: >
: > PS. another question. I have a degree in electronics and
: > am experienced in componentl level debugging of microprocessor
: > based systems. So, I'm not intimidated by the electronics of the
: > fuel injection system, however, as knowledgeable as one might
: > be in this field, troubleshooting such circuits are a major ordeal
: > unless decent service literature can be obtained
: >
: > So, the last question is,, what kind of service literature can I
: expect
: > to find in this regard? I'm guessing that the microprocessor
: module
: > is going to be treated pretty much as a "black box" with little
: or no
: > information as to what's inside it,, right?
: >
: > Thanks very much
: > But even more, thanks from my wife
: > who is at wits end needing her truck.
: >
: > --Dave--
: >
: >
:
:

[Dave Moore]

"Steve T" <fotocord@yahoo.com> wrote in message news:2vau9nF2ifdfeU1@uni-berlin.de...
: Dave Moore wrote:
:
:
: >
: > I guess it should be mentioned that the mechanics put
: > in "used" parts salvaged off of another truck which had
: > been rear ended. We don't use this truck nearly as much as
: > a lot of people might, so I am thinking, perhaps the parts
: > they put in might be as worn out or even worse than the
: > originals.
:
: Bingo.
:
:
: >
: > PS. another question. I have a degree in electronics and
: > am experienced in componentl level debugging of microprocessor
: > based systems. So, I'm not intimidated by the electronics of the
: > fuel injection system, however, as knowledgeable as one might
: > be in this field, troubleshooting such circuits are a major ordeal
: > unless decent service literature can be obtained
: >
: > So, the last question is,, what kind of service literature can I
: > expect
: > to find in this regard?
:
: Zero.
:
: > I'm guessing that the microprocessor
: > module is going to be treated pretty much as a "black box" with
: > little or no
: > information as to what's inside it,, right?
:
: Exactly. There are stand alone EFI systems that allow the user to program
: the fuel curves etc (we install these systems on -hot rod- cars) but for
: the OE electronics, they don't supply any info on the core programing.


)`:



: BTW this sounds like a "hot wire" air sensor problem to me. Someone with
: some sense might be able to clean it and fix the problem.

There's a gizmo ma-bob that they gave me that he said was some kind
of air sensor, and he said, "see how that dirt dauber ate through the side
of it" because the edge of it was chewed off and there was a dirt dauber
mud nest on it also.
However, I think it got chewed by a small rat or mouse that was living
in the truck until it got gutted by the fan belt or something one day.

Sometimes when we'd back the truck out, the little guy would bail
and head back for the garage. I tried to catch the little bugger, but
he out maneuvered me :-) So the next plan was have one of our better
mouser cats ready to do the honors, but twice when I had the cat
on standby, the little guy was nowhere to be found. Then after that,
his luck turned sour anyway.

So, I have the gizmo ma-bob that is supposed to be an air sensor
and looking inside you can see some kind of gold plated structures
in it. I''ll drag it in tomorrow and have a better look.

Something should probably should be mentioned. When the motor
is started cold, it starts ok, but after it has run awhile and is at a stable
operating temperature, it has trouble starting.

So this would seem to jive possibly with what you said about the
hot air sensor maybe?

However, when it has trouble starting, it acts like the starter motor
is too weak to crank the motor, like the battery is weak or there's too
much voltage drop to starter motor. But I still am scratching my
head as to why any of those things would be worse when warm.

I mean, even if you were to remove all gas and fire from a motor,
the starter motor should still crank the engine at least 10 or more
revolutions I would think, but when it's warm, you better hope the fire
and gas kick in after a few revolutions or you're out of luck.

So I believe that the starting problem is probably a separate problem
from the other high speed lugging problem
IOW, a problem with the battery, solenoid or starter motor.
Unless the friction of the motor is simply becoming atrocious when it's hot.

I'm not too worried about the sarting system problem, I can certainly
diagnose that myself, but the high speed lugging problem is a bit beyond
my scope of knowledge, which ends at standard old time carburetion

: Has anyone
: checked the fuel pressure when the problem occures?

The mechanics supposedly originally fixed a problem with the
fuel pressure being too high. Unfortunately, I haven't gotten them
to relate specifically what was causing that problem and just exactly
what they replaced or did to recitify it.


:Another question, are
: you using bosch platium spark plugs? I've seen these cause all kinds of
: starnge problems like this.

It's quite possible I am. I recall buying some at one time. But though
I do remember putting them in my 82 Corolla wagon, I can't recall if
I put any in the truck.


Anyway, the trucks back with the mechanics and one guy said that
perhaps it needs a bit of tweaking after the new micro-module self
adjusts itself, or after the other parts seat or break in some.

I should have some word soon, and if they nail it, I'll certainly
report the results. If not, I'll just jump off the nearest bridge :-)

Thanks a lot for the advice
--dave--



:
: --
:
: Steve
:
: http://www.atlantaracing.com

[Dave Moore]

"Meat Plow" <meat@insurgent.orq> wrote in message news:pan.2004.11.08.13.38.56.562481@insurgent.orq...
: On Sun, 07 Nov 2004 19:33:49 -0600, Dave Moore wrote:
:
: > 92 Nissan PU 2.4 Litre/146 cubic inch OHC , 4 cyl , Elect Multi-PT fuel
: > injection feedback fuel system, catalytic converter
: >
: >
: > Crikey,
: > My mechanics have changed out the computer module, the throttle sensor and
: > also some kind of air sensor all supposedly related to a fuel injection
: > problem
: >
: > They also, replaced the timing chain, worn but not
: > totally kaput yet. ( approx 110,000 miles )
:
: TPS ?


I give up, what does 'TPS" mean ?

[willshak]

Dave Moore wrote:

[Dave Moore]

"willshak" <willshak@hvc.rr.com> wrote in message news:10p3tftqpaqub53@news.supernews.com...
: Dave Moore wrote:
:
: >"Meat Plow" <meat@insurgent.orq> wrote in message news:pan.2004.11.08.13.38.56.562481@insurgent.orq...
: >: On Sun, 07 Nov 2004 19:33:49 -0600, Dave Moore wrote:
: >:
: >: > 92 Nissan PU 2.4 Litre/146 cubic inch OHC , 4 cyl , Elect Multi-PT fuel
: >: > injection feedback fuel system, catalytic converter
: >: >
: >: >
: >: > Crikey,
: >: > My mechanics have changed out the computer module, the throttle sensor and
: >: > also some kind of air sensor all supposedly related to a fuel injection
: >: > problem
: >: >
: >: > They also, replaced the timing chain, worn but not
: >: > totally kaput yet. ( approx 110,000 miles )
: >:
: >: TPS ?
: >
: >
: > I give up, what does 'TPS" mean ?
: >
: Throttle Position Sensor

Oh, that's all ? Thanks.
There's some guy in another newsgroup whose
handle is "TPS", so I thought maybe it had some
kind of esoteric meaning or something :-)

They did change out the TPS, only they got it from another truck in
a wrecking yard which might even have more wear on it, who knows.

I did some measurements on the original one and the resistance is
very solid without any bad spots, except near the beginning of it's travel
there are some inconsistancies.
( assuming that "the beginning of it's travel" is at
the position where the internal spring returns it to)

Considering that the problems seemed to occur around the
midpoint of the accelerator, I guess any inconsistancies at either end
of the TPS probably wouldn't account for the problem.