mbradburn1
New Member
Well,
If you want to see the diagrams below properly, send me an e-mail and I will send them in a text attachment.
Problem: hesitation/Bog at 4000 RPM when secondaries open up at WOT. Very intermittent...
The good news is my car is back to running normal. The bad news is the
only thing I did was remove the computer and LPM to attach a break out
box for some pin point testing and did a lot of probing.
Here is what I found...
1. Fuel pressure = 36 at idle, 41 at WOT, even with the car hesitating
and acting like it was running out of fuel or spark.
2. Cleaned the wires on the MAF. Did not help one bit, but they were
not dirty.
3. Added the break out box and probed all circuits with DVOM or
o-scope. Here is what I found normal..
ECT was normal
TPS
BAP
PST - Power steering Switch
Intake Air Temp
Knock sensor
O2's
CID
4. Here is what I am not sure if it is normal or not.
The PIP (CSP) (Pin 56) had some interesting results on the
o-scope. At idle, the voltage wave looked like this:
________
| |
| |
_______| |______
with the peak at around 12.5v or so. As the RPM's were raised, the top
of the PIP voltage was getting cut off, so at around 3500 RPM, the wave
looked like this...
__
| |_____
| |
_______| |______
The spike is the original 12.5 v or so and the flat part is around 9.9v.
At 4000 RPM the whole graph was at 9.9v or so. BTW, 4000 RPM is where
my stumble/hesitation occurs.
Is the PIP supposed to lose voltage like this at higher RPM's? This
looks very strange to me.
Also, the SPOUT has something that did not look very normal as well. At
idle, it has a little hic-up on it's wave like this:
________ ________
|_____ _| |____
| | |
| | |
|______| |
The hic-up I am concerned about is the one on the left hand of the second wave shown above. The shelf on the right is normal for Fords. The shelf
on the left is not there for all waves. I had to keep pausing the meter
to get a print out of this since it is intermittent.
At about 3500 RPM, the SPOUT looks very much like the PIP, but just
opposite like this:
__
_____| |
| |
_______| |______
None of these look normal and I was wondering if anyone has looked at
this before on our cars? I have these waves on print outs, so they can
be faxed if needed or if this e-mail does not get spaced properly.
The LPM is back in w/o any effects and all testing was done w/o it
installed.
Other things that we think my be causing the hesitation is a loose
baffle in the muffler causing the knock sensor to freak out. We do hear
a slight rattle in the exhaust but had not been able to pinpoint it yet.
Thanks ahead of time for any help.
Mike
[This message has been edited by mbradburn1 (edited 11-19-2001).]
[This message has been edited by mbradburn1 (edited 11-19-2001).]
[This message has been edited by mbradburn1 (edited 11-19-2001).]
If you want to see the diagrams below properly, send me an e-mail and I will send them in a text attachment.
Problem: hesitation/Bog at 4000 RPM when secondaries open up at WOT. Very intermittent...
The good news is my car is back to running normal. The bad news is the
only thing I did was remove the computer and LPM to attach a break out
box for some pin point testing and did a lot of probing.
Here is what I found...
1. Fuel pressure = 36 at idle, 41 at WOT, even with the car hesitating
and acting like it was running out of fuel or spark.
2. Cleaned the wires on the MAF. Did not help one bit, but they were
not dirty.
3. Added the break out box and probed all circuits with DVOM or
o-scope. Here is what I found normal..
ECT was normal
TPS
BAP
PST - Power steering Switch
Intake Air Temp
Knock sensor
O2's
CID
4. Here is what I am not sure if it is normal or not.
The PIP (CSP) (Pin 56) had some interesting results on the
o-scope. At idle, the voltage wave looked like this:
________
| |
| |
_______| |______
with the peak at around 12.5v or so. As the RPM's were raised, the top
of the PIP voltage was getting cut off, so at around 3500 RPM, the wave
looked like this...
__
| |_____
| |
_______| |______
The spike is the original 12.5 v or so and the flat part is around 9.9v.
At 4000 RPM the whole graph was at 9.9v or so. BTW, 4000 RPM is where
my stumble/hesitation occurs.
Is the PIP supposed to lose voltage like this at higher RPM's? This
looks very strange to me.
Also, the SPOUT has something that did not look very normal as well. At
idle, it has a little hic-up on it's wave like this:
________ ________
|_____ _| |____
| | |
| | |
|______| |
The hic-up I am concerned about is the one on the left hand of the second wave shown above. The shelf on the right is normal for Fords. The shelf
on the left is not there for all waves. I had to keep pausing the meter
to get a print out of this since it is intermittent.
At about 3500 RPM, the SPOUT looks very much like the PIP, but just
opposite like this:
__
_____| |
| |
_______| |______
None of these look normal and I was wondering if anyone has looked at
this before on our cars? I have these waves on print outs, so they can
be faxed if needed or if this e-mail does not get spaced properly.
The LPM is back in w/o any effects and all testing was done w/o it
installed.
Other things that we think my be causing the hesitation is a loose
baffle in the muffler causing the knock sensor to freak out. We do hear
a slight rattle in the exhaust but had not been able to pinpoint it yet.
Thanks ahead of time for any help.
Mike
[This message has been edited by mbradburn1 (edited 11-19-2001).]
[This message has been edited by mbradburn1 (edited 11-19-2001).]
[This message has been edited by mbradburn1 (edited 11-19-2001).]
