ECU for Jeep Cherokee
#51
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
reigelser did pass the time by typing:
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately. There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
What your describing may be a fuel delivery problem caused by either
the pressure regulator or check valve failing. Try this;
Turn the key on, but don't crank.
Turn the key off, wait a sec
Turn the key on, wait for the fuel pump to stop buzzing
Then try starting the engine.
If the engine fires up your problem is fuel pressure leaking
down. Diagnosing that further is slightly complicated but a cheap
fuel pressure gauge screwed into the fuel rail will indicate a leak
if it drops more than 5psi in an hour. The rail should hold pressure
for more than a day.
--
DougW
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately. There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
What your describing may be a fuel delivery problem caused by either
the pressure regulator or check valve failing. Try this;
Turn the key on, but don't crank.
Turn the key off, wait a sec
Turn the key on, wait for the fuel pump to stop buzzing
Then try starting the engine.
If the engine fires up your problem is fuel pressure leaking
down. Diagnosing that further is slightly complicated but a cheap
fuel pressure gauge screwed into the fuel rail will indicate a leak
if it drops more than 5psi in an hour. The rail should hold pressure
for more than a day.
--
DougW
#52
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
reigelser did pass the time by typing:
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately. There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
What your describing may be a fuel delivery problem caused by either
the pressure regulator or check valve failing. Try this;
Turn the key on, but don't crank.
Turn the key off, wait a sec
Turn the key on, wait for the fuel pump to stop buzzing
Then try starting the engine.
If the engine fires up your problem is fuel pressure leaking
down. Diagnosing that further is slightly complicated but a cheap
fuel pressure gauge screwed into the fuel rail will indicate a leak
if it drops more than 5psi in an hour. The rail should hold pressure
for more than a day.
--
DougW
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately. There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
What your describing may be a fuel delivery problem caused by either
the pressure regulator or check valve failing. Try this;
Turn the key on, but don't crank.
Turn the key off, wait a sec
Turn the key on, wait for the fuel pump to stop buzzing
Then try starting the engine.
If the engine fires up your problem is fuel pressure leaking
down. Diagnosing that further is slightly complicated but a cheap
fuel pressure gauge screwed into the fuel rail will indicate a leak
if it drops more than 5psi in an hour. The rail should hold pressure
for more than a day.
--
DougW
#53
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
reigelser did pass the time by typing:
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately. There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
What your describing may be a fuel delivery problem caused by either
the pressure regulator or check valve failing. Try this;
Turn the key on, but don't crank.
Turn the key off, wait a sec
Turn the key on, wait for the fuel pump to stop buzzing
Then try starting the engine.
If the engine fires up your problem is fuel pressure leaking
down. Diagnosing that further is slightly complicated but a cheap
fuel pressure gauge screwed into the fuel rail will indicate a leak
if it drops more than 5psi in an hour. The rail should hold pressure
for more than a day.
--
DougW
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately. There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
What your describing may be a fuel delivery problem caused by either
the pressure regulator or check valve failing. Try this;
Turn the key on, but don't crank.
Turn the key off, wait a sec
Turn the key on, wait for the fuel pump to stop buzzing
Then try starting the engine.
If the engine fires up your problem is fuel pressure leaking
down. Diagnosing that further is slightly complicated but a cheap
fuel pressure gauge screwed into the fuel rail will indicate a leak
if it drops more than 5psi in an hour. The rail should hold pressure
for more than a day.
--
DougW
#54
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
"reigelser" <reigelser@sbcglobal.net> wrote in message news:7%yre.858$aa2.546@newssvr17.news.prodigy.com. ..
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately.
You may have more than one problem... try this
sometime... turn on the key, let the thing sit for
ten seconds, then crank... should go vroom.
It this is what you're seeing, you have a fuel
pressure retention problem... either the back-
check valve, or a leaky injector.
> There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
I'm not that big of a believer in engine cleaning...
especially when trying to troubleshoot a problem.
Don't compound your problems right now.. sounds
to me like you've got more than one.
Is the big braided ground wire still connected
between the block and firewall? Look good?
Get some Caig ProGold contact cleaner (sold at Fry's)
and put some in the connector (both ends) for the
TPS... try again. I want to verify that you've cleared
the old ECU code, and it keeps popping a new one...
am I right? Does it pop immediately, or after normal
in-town driving, or only after exhibiting the symptoms
you describe at 60-70mph transition?
__
Steve
..
Lastly, you may have to go through several run/drive
cycles for the ECU to learn the curve of the new TPS...
#55
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
"reigelser" <reigelser@sbcglobal.net> wrote in message news:7%yre.858$aa2.546@newssvr17.news.prodigy.com. ..
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately.
You may have more than one problem... try this
sometime... turn on the key, let the thing sit for
ten seconds, then crank... should go vroom.
It this is what you're seeing, you have a fuel
pressure retention problem... either the back-
check valve, or a leaky injector.
> There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
I'm not that big of a believer in engine cleaning...
especially when trying to troubleshoot a problem.
Don't compound your problems right now.. sounds
to me like you've got more than one.
Is the big braided ground wire still connected
between the block and firewall? Look good?
Get some Caig ProGold contact cleaner (sold at Fry's)
and put some in the connector (both ends) for the
TPS... try again. I want to verify that you've cleared
the old ECU code, and it keeps popping a new one...
am I right? Does it pop immediately, or after normal
in-town driving, or only after exhibiting the symptoms
you describe at 60-70mph transition?
__
Steve
..
Lastly, you may have to go through several run/drive
cycles for the ECU to learn the curve of the new TPS...
#56
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
"reigelser" <reigelser@sbcglobal.net> wrote in message news:7%yre.858$aa2.546@newssvr17.news.prodigy.com. ..
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately.
You may have more than one problem... try this
sometime... turn on the key, let the thing sit for
ten seconds, then crank... should go vroom.
It this is what you're seeing, you have a fuel
pressure retention problem... either the back-
check valve, or a leaky injector.
> There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
I'm not that big of a believer in engine cleaning...
especially when trying to troubleshoot a problem.
Don't compound your problems right now.. sounds
to me like you've got more than one.
Is the big braided ground wire still connected
between the block and firewall? Look good?
Get some Caig ProGold contact cleaner (sold at Fry's)
and put some in the connector (both ends) for the
TPS... try again. I want to verify that you've cleared
the old ECU code, and it keeps popping a new one...
am I right? Does it pop immediately, or after normal
in-town driving, or only after exhibiting the symptoms
you describe at 60-70mph transition?
__
Steve
..
Lastly, you may have to go through several run/drive
cycles for the ECU to learn the curve of the new TPS...
#57
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
"reigelser" <reigelser@sbcglobal.net> wrote in message news:7%yre.858$aa2.546@newssvr17.news.prodigy.com. ..
> To start the car I have to crank it once for a short time. Even If I crank
> longer it won't start. Then I turn the ignition off completely and start
> again and runs immediately.
You may have more than one problem... try this
sometime... turn on the key, let the thing sit for
ten seconds, then crank... should go vroom.
It this is what you're seeing, you have a fuel
pressure retention problem... either the back-
check valve, or a leaky injector.
> There was no service done prior to the Check
> engine light coming on. The wiper voltage seems very smooth and stable. I
> haven't measured the supply voltage while having the engine running yet.
> Everything else seems to run good: idle speed, kick down response. So would
> you recommend an engine cleaning first (engine compartment wasn't cleaned in
> a loooong time) and then a rework of the connectors?
> Thanks for all of your advice.
I'm not that big of a believer in engine cleaning...
especially when trying to troubleshoot a problem.
Don't compound your problems right now.. sounds
to me like you've got more than one.
Is the big braided ground wire still connected
between the block and firewall? Look good?
Get some Caig ProGold contact cleaner (sold at Fry's)
and put some in the connector (both ends) for the
TPS... try again. I want to verify that you've cleared
the old ECU code, and it keeps popping a new one...
am I right? Does it pop immediately, or after normal
in-town driving, or only after exhibiting the symptoms
you describe at 60-70mph transition?
__
Steve
..
Lastly, you may have to go through several run/drive
cycles for the ECU to learn the curve of the new TPS...
#58
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
i have not seen in any posts giving a dtc for a tps issue
i have seen and replaced many a tps for a glitch in it's range causing all sorts of issues and some serious
testing with a drb and a dvom must take place
could be there is a couple of things going wrong though???
like the plug wires are shot. carbon on th valve thats causing a highway speed misfire and there was a tsb on
new valve springs for this issue and a weak battery
h
Stephen Cowell wrote:
> "reigelser" <reigelser@sbcglobal.net> wrote in message news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> > I need the ECU eventually because of a persistent TPS error. My mechanic
> > troubleshooted it and thinks its probably the ECU. But he thinks there has
> > to be some reprogramming to be done, because I tried one from the junk yard
> > before he looked into it and nothing changed (same TPS error, same mileage).
> > It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> > it is not very smooth if you want to accelerate from 65 to 75 without a
> > kickdown.
>
> So it only throws a 24 code? Do you have a manual
> or automatic transmission? Any aftermarket parts
> on the engine? It's never thrown a 15 (VSS)? That
> causes kickdown problems too...
>
> With the TPS, you can actually patch a digital
> voltmeter in and watch the voltage as you drive...
> won't hurt a thing. If the computer's bad, then
> you'd expect the +V to the TPS to fluctuate...
> if the TPS is bad, you'd expect the wiper return
> voltage to be wrong for the rpm, gear, etc.
> That's what I'd do next...
> __
> Steve
> .
i have seen and replaced many a tps for a glitch in it's range causing all sorts of issues and some serious
testing with a drb and a dvom must take place
could be there is a couple of things going wrong though???
like the plug wires are shot. carbon on th valve thats causing a highway speed misfire and there was a tsb on
new valve springs for this issue and a weak battery
h
Stephen Cowell wrote:
> "reigelser" <reigelser@sbcglobal.net> wrote in message news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> > I need the ECU eventually because of a persistent TPS error. My mechanic
> > troubleshooted it and thinks its probably the ECU. But he thinks there has
> > to be some reprogramming to be done, because I tried one from the junk yard
> > before he looked into it and nothing changed (same TPS error, same mileage).
> > It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> > it is not very smooth if you want to accelerate from 65 to 75 without a
> > kickdown.
>
> So it only throws a 24 code? Do you have a manual
> or automatic transmission? Any aftermarket parts
> on the engine? It's never thrown a 15 (VSS)? That
> causes kickdown problems too...
>
> With the TPS, you can actually patch a digital
> voltmeter in and watch the voltage as you drive...
> won't hurt a thing. If the computer's bad, then
> you'd expect the +V to the TPS to fluctuate...
> if the TPS is bad, you'd expect the wiper return
> voltage to be wrong for the rpm, gear, etc.
> That's what I'd do next...
> __
> Steve
> .
#59
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
i have not seen in any posts giving a dtc for a tps issue
i have seen and replaced many a tps for a glitch in it's range causing all sorts of issues and some serious
testing with a drb and a dvom must take place
could be there is a couple of things going wrong though???
like the plug wires are shot. carbon on th valve thats causing a highway speed misfire and there was a tsb on
new valve springs for this issue and a weak battery
h
Stephen Cowell wrote:
> "reigelser" <reigelser@sbcglobal.net> wrote in message news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> > I need the ECU eventually because of a persistent TPS error. My mechanic
> > troubleshooted it and thinks its probably the ECU. But he thinks there has
> > to be some reprogramming to be done, because I tried one from the junk yard
> > before he looked into it and nothing changed (same TPS error, same mileage).
> > It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> > it is not very smooth if you want to accelerate from 65 to 75 without a
> > kickdown.
>
> So it only throws a 24 code? Do you have a manual
> or automatic transmission? Any aftermarket parts
> on the engine? It's never thrown a 15 (VSS)? That
> causes kickdown problems too...
>
> With the TPS, you can actually patch a digital
> voltmeter in and watch the voltage as you drive...
> won't hurt a thing. If the computer's bad, then
> you'd expect the +V to the TPS to fluctuate...
> if the TPS is bad, you'd expect the wiper return
> voltage to be wrong for the rpm, gear, etc.
> That's what I'd do next...
> __
> Steve
> .
i have seen and replaced many a tps for a glitch in it's range causing all sorts of issues and some serious
testing with a drb and a dvom must take place
could be there is a couple of things going wrong though???
like the plug wires are shot. carbon on th valve thats causing a highway speed misfire and there was a tsb on
new valve springs for this issue and a weak battery
h
Stephen Cowell wrote:
> "reigelser" <reigelser@sbcglobal.net> wrote in message news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> > I need the ECU eventually because of a persistent TPS error. My mechanic
> > troubleshooted it and thinks its probably the ECU. But he thinks there has
> > to be some reprogramming to be done, because I tried one from the junk yard
> > before he looked into it and nothing changed (same TPS error, same mileage).
> > It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> > it is not very smooth if you want to accelerate from 65 to 75 without a
> > kickdown.
>
> So it only throws a 24 code? Do you have a manual
> or automatic transmission? Any aftermarket parts
> on the engine? It's never thrown a 15 (VSS)? That
> causes kickdown problems too...
>
> With the TPS, you can actually patch a digital
> voltmeter in and watch the voltage as you drive...
> won't hurt a thing. If the computer's bad, then
> you'd expect the +V to the TPS to fluctuate...
> if the TPS is bad, you'd expect the wiper return
> voltage to be wrong for the rpm, gear, etc.
> That's what I'd do next...
> __
> Steve
> .
#60
Guest
Posts: n/a
Re: ECU for Jeep Cherokee
i have not seen in any posts giving a dtc for a tps issue
i have seen and replaced many a tps for a glitch in it's range causing all sorts of issues and some serious
testing with a drb and a dvom must take place
could be there is a couple of things going wrong though???
like the plug wires are shot. carbon on th valve thats causing a highway speed misfire and there was a tsb on
new valve springs for this issue and a weak battery
h
Stephen Cowell wrote:
> "reigelser" <reigelser@sbcglobal.net> wrote in message news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> > I need the ECU eventually because of a persistent TPS error. My mechanic
> > troubleshooted it and thinks its probably the ECU. But he thinks there has
> > to be some reprogramming to be done, because I tried one from the junk yard
> > before he looked into it and nothing changed (same TPS error, same mileage).
> > It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> > it is not very smooth if you want to accelerate from 65 to 75 without a
> > kickdown.
>
> So it only throws a 24 code? Do you have a manual
> or automatic transmission? Any aftermarket parts
> on the engine? It's never thrown a 15 (VSS)? That
> causes kickdown problems too...
>
> With the TPS, you can actually patch a digital
> voltmeter in and watch the voltage as you drive...
> won't hurt a thing. If the computer's bad, then
> you'd expect the +V to the TPS to fluctuate...
> if the TPS is bad, you'd expect the wiper return
> voltage to be wrong for the rpm, gear, etc.
> That's what I'd do next...
> __
> Steve
> .
i have seen and replaced many a tps for a glitch in it's range causing all sorts of issues and some serious
testing with a drb and a dvom must take place
could be there is a couple of things going wrong though???
like the plug wires are shot. carbon on th valve thats causing a highway speed misfire and there was a tsb on
new valve springs for this issue and a weak battery
h
Stephen Cowell wrote:
> "reigelser" <reigelser@sbcglobal.net> wrote in message news:m7ore.757$aa2.19@newssvr17.news.prodigy.com.. .
> > I need the ECU eventually because of a persistent TPS error. My mechanic
> > troubleshooted it and thinks its probably the ECU. But he thinks there has
> > to be some reprogramming to be done, because I tried one from the junk yard
> > before he looked into it and nothing changed (same TPS error, same mileage).
> > It's a 97 inline 6 Cherokee. It works, but it doesn't start at first try and
> > it is not very smooth if you want to accelerate from 65 to 75 without a
> > kickdown.
>
> So it only throws a 24 code? Do you have a manual
> or automatic transmission? Any aftermarket parts
> on the engine? It's never thrown a 15 (VSS)? That
> causes kickdown problems too...
>
> With the TPS, you can actually patch a digital
> voltmeter in and watch the voltage as you drive...
> won't hurt a thing. If the computer's bad, then
> you'd expect the +V to the TPS to fluctuate...
> if the TPS is bad, you'd expect the wiper return
> voltage to be wrong for the rpm, gear, etc.
> That's what I'd do next...
> __
> Steve
> .