Engine or electrical problem with a 1998 Plymouth Grand Voyager

I have been having a problem for several months now with my 98 Voyager:
it will shudder for a second or two and then the gas pedal will stop
responding. If I am going at a high enough speed (55-60 mph) when I
floor the pedal, it will all of a sudden, respond, with the rpms
shooting up from a start-point of 2000 to potentially as high as 5500.
My speed, however, will only increase about 4 or 5 mph. As I do this,
the transmission sounds as if it's shifting at the last possible
moment. When it finally shifts, there is a steady decrease in speed
until the van finally responds to the gas pedal being depressed and
then there's the rapid increase of rpms as I described before.
If I am going at slower speeds, it is much more difficult to keep it at
a constant speed. As I was trying to keep it at 35 yesterday, there
was none of the rapid rpm increases; although I had my foot on the gas,
most of the time the van would just very slowly coast and occasionally
speed up a bit, but my speed was normally somewhere between 10 and 20
mph. Also, it started to make a popping sound and I could feel
something popping underneath the van on the driver's side. I noticed
there is something hanging down the I know I have a broken CV boot,
and maybe that's it? But there was a time about a month ago that the
same popping occurred and I didn't notice anything hanging down then.
Also yesterday as I tried to make it through a series of stoplights, I
could hardly get the van to respond at all--it would barely go when I
accelerated and the transmission was shifting in a funny way.
When the van is acting up like this, most of the times all I have to do
is pull by the side of the road and let it idle for a minute or two and
then it's fine--I've even driven it 45 miles without it acting up
afterward. I have on two occasions smelled some burning smell after
prolonged driving while it is acting up, but I have not smelled it if
the van's been driving fine. The problem has occured several times as
I tried to drive up a large hill.
This problem does not occur every time we drive the van, nor does the
engine die--the accelerator just does not respond. We have replaced the
spark plugs and distributor cap, the fuel filters have been replaced as
has the fuel pump and although we are unsure as to whether or not the
mechanic cleaned out the fuel tank after he replaced the fuel pump,
nearly everything else about the fuel system has been cleaned out.
Two other pieces to the puzzle: my cruise control may or may not work
during the same period of driving, and although the battery and
alternator are fine, the van tested before as having an electrical
output of 1.5 volts.
The theory about my van is that it has some electrical problem which is
causing the transmission to act up, and the problem is not with the
transmission itself. The transmission has been replaced on this van,
although the engine has not.
We have let four different mechanics look at it, and none have been
able to fix it. We are desperately in need of some help! If you have
any ideas as to what is wrong, please let us know!

Also, I failed to include that when the van acts up, the gas pedal has
to be nearly pressed to the floor to get it to respond, if it will.

"Yebba Enna" > wrote in message
oups.com...
> I have been having a problem for several months now with my 98 Voyager:
> it will shudder for a second or two and then the gas pedal will stop
> responding. If I am going at a high enough speed (55-60 mph) when I

TPS sensor?

You really need to take this in and have them run a full set of electrical
diagnostics on it with a scan tool.

Ted

any fault codes???

Yebba Enna wrote:

> I have been having a problem for several months now with my 98 Voyager:
> it will shudder for a second or two and then the gas pedal will stop
> responding. If I am going at a high enough speed (55-60 mph) when I
> floor the pedal, it will all of a sudden, respond, with the rpms
> shooting up from a start-point of 2000 to potentially as high as 5500.
> My speed, however, will only increase about 4 or 5 mph. As I do this,
> the transmission sounds as if it's shifting at the last possible
> moment. When it finally shifts, there is a steady decrease in speed
> until the van finally responds to the gas pedal being depressed and
> then there's the rapid increase of rpms as I described before.
> If I am going at slower speeds, it is much more difficult to keep it at
> a constant speed. As I was trying to keep it at 35 yesterday, there
> was none of the rapid rpm increases; although I had my foot on the gas,
> most of the time the van would just very slowly coast and occasionally
> speed up a bit, but my speed was normally somewhere between 10 and 20
> mph. Also, it started to make a popping sound and I could feel
> something popping underneath the van on the driver's side. I noticed
> there is something hanging down the I know I have a broken CV boot,
> and maybe that's it? But there was a time about a month ago that the
> same popping occurred and I didn't notice anything hanging down then.
> Also yesterday as I tried to make it through a series of stoplights, I
> could hardly get the van to respond at all--it would barely go when I
> accelerated and the transmission was shifting in a funny way.
> When the van is acting up like this, most of the times all I have to do
> is pull by the side of the road and let it idle for a minute or two and
> then it's fine--I've even driven it 45 miles without it acting up
> afterward. I have on two occasions smelled some burning smell after
> prolonged driving while it is acting up, but I have not smelled it if
> the van's been driving fine. The problem has occured several times as
> I tried to drive up a large hill.
> This problem does not occur every time we drive the van, nor does the
> engine die--the accelerator just does not respond. We have replaced the
> spark plugs and distributor cap, the fuel filters have been replaced as
> has the fuel pump and although we are unsure as to whether or not the
> mechanic cleaned out the fuel tank after he replaced the fuel pump,
> nearly everything else about the fuel system has been cleaned out.
> Two other pieces to the puzzle: my cruise control may or may not work
> during the same period of driving, and although the battery and
> alternator are fine, the van tested before as having an electrical
> output of 1.5 volts.
> The theory about my van is that it has some electrical problem which is
> causing the transmission to act up, and the problem is not with the
> transmission itself. The transmission has been replaced on this van,
> although the engine has not.
> We have let four different mechanics look at it, and none have been
> able to fix it. We are desperately in need of some help! If you have
> any ideas as to what is wrong, please let us know!

My understanding is that if the TPS sensor were failing, it would have
a fast idle. If this is the case, then the TPS sensor is not it. The
problem is that the van has been scanned, but no codes come up.

No codes.

"Yebba Enna" > wrote in message
oups.com...
> My understanding is that if the TPS sensor were failing, it would have
> a fast idle.

No, not exactly true. The TPS is basically a variable resistor/rehostat.
Because the wiper spends most of it's time down at the slow speed end of the
rehostat, that is the part that wears the most and so a change in idle is a
more common symptom, but that is not the only way they fail.

But, as I said, you really need a full set of electrical diagnostics. A
scan tool
does more than just read codes.

Ted

Ah, I see. I had assumed that code-reading and electrical diagnostics
were one and the same. Thanks.