Troubleshooting ECU code 45 from 93 Nissan Altima

Hi. I'm having a hard time troubleshooting code 45 from my ECU. I got
the code using a custom board I bought on ebay with the conzult
freeware version.

The idle has been running very rough. I've been running the STP gas
treatment every tankful, and that has helped a little bit. More on the
problem:

* erratic idle, sometimes stalling when go from high RPM's to slowing
to stop idle.
* erratic idle when warmed up, when the fan clicks off and the RPM's
drop, sometimes it drops to the stalling point. Lately, it's been
better since I've been using the cleaner to cleanout some of the carbon
deposits. Some info on the car.

* '93 Altima with 153k miles on it
* Distributor, plugs, wires, cap, O2 sensor all 1 year old.
* Engine definitely running rich - strong smell with 10% drop in
mileage
* No noticable problems at highway speeds

So if any tech or anybody knows what would be the cause of this code, I
would really appreciate the help. Thanks, Bill

willydog wrote:

Hi. I'm having a hard time troubleshooting code 45 from my ECU. I got
the code using a custom board I bought on ebay with the conzult
freeware version.

The idle has been running very rough. I've been running the STP gas
treatment every tankful, and that has helped a little bit. More on the
problem:

* erratic idle, sometimes stalling when go from high RPM's to slowing
to stop idle.
* erratic idle when warmed up, when the fan clicks off and the RPM's
drop, sometimes it drops to the stalling point. Lately, it's been
better since I've been using the cleaner to cleanout some of the carbon
deposits. Some info on the car.

* '93 Altima with 153k miles on it
* Distributor, plugs, wires, cap, O2 sensor all 1 year old.
* Engine definitely running rich - strong smell with 10% drop in
mileage
* No noticable problems at highway speeds

So if any tech or anybody knows what would be the cause of this code, I
would really appreciate the help. Thanks, Bill

willydog,

I looked in my 1992 Pathy manual for EC 45. I am assuming it has very
similar ECU firmware as your Altima. It seems to be leaky fuel
injector/s.Your symptoms are indicative of fuel injector problem. Do you
have access to a fuel pressure gage? You could put on the fuel rail and
see if the system holds pressure after cycling power to the fuel pump. I
think it should hold within about 5 psi for 2 minutes. As far as
tracking down the offending injector if the fuel pressure test fails you
could let the engine cool after a warm up then turn on the ignition to
get the fuel pump to cycle and crank the engine with the coil wire
disconnected and grounded to the engine. Also you need to disable the
fuel pump during cranking. The idea is to get the leaky injector/s to
release gas into the cylinder and then see the gas on the spark plug.
This sounds complicated and I would invite someone else to pitch in on a
better way finding the leaker.

Good Luck
Sparky

willydog wrote:

Hi. I'm having a hard time troubleshooting code 45 from my ECU. I got
the code using a custom board I bought on ebay with the conzult
freeware version.

The idle has been running very rough. I've been running the STP gas
treatment every tankful, and that has helped a little bit. More on the
problem:

* erratic idle, sometimes stalling when go from high RPM's to slowing
to stop idle.
* erratic idle when warmed up, when the fan clicks off and the RPM's
drop, sometimes it drops to the stalling point. Lately, it's been
better since I've been using the cleaner to cleanout some of the carbon
deposits. Some info on the car.

* '93 Altima with 153k miles on it
* Distributor, plugs, wires, cap, O2 sensor all 1 year old.
* Engine definitely running rich - strong smell with 10% drop in
mileage
* No noticable problems at highway speeds

So if any tech or anybody knows what would be the cause of this code, I
would really appreciate the help. Thanks, Bill

I don't know about the code, but seen something very similar happen
with a Mass Air Flow (MAF) sensor on a friend's car.

Remco

Thanks guys - from what I've read, you can use a listening device to
listen for a bad injector - if that happens, then the problem is (at
least partially) identified.

The car is running rich - but I should correct that it's not a strong
smell from the engine compartment - the exhaust definitely smells rich
though. It looks like my gas mileage is somewhere around 10% off too.
Some other symptoms:

* If I cluch in at very low RPM's, the idle remains fairly strong.

* The idle has hunted in th past all the way from close to 0 to 900
RPM. After using 5 gas cleaners over the last 6 weeks, it seems pretty
solid at around 600-900 RPM.

Does anyone know if things like the IACV/AAC and the EGR can be
component tested thorugh software? I'm using the freeware version of
conzult, with a board I bought off ebay. If there is anyway I can do
some tests with software, that would be ideal. It's getting cold up
here, and I don't have access to a warm garage to do some component
testing with the volt meter. I checked the EGR, but I believe it all
needs to be taken apart and cleaned, and I would prefer to isolate the
failing component first.

Thanks in advance for your courteous replies. Bill

check for an excessive voltage drop on the ground wire at the air flow
meter.

The above described condition can cause the injector leak code to be stored

if the drop is in excess of .020 volts or more you have a problem


"willydog" <vette98dude (AT) yahoo (DOT) com> wrote

Hi. I'm having a hard time troubleshooting code 45 from my ECU. I got
the code using a custom board I bought on ebay with the conzult
freeware version.

The idle has been running very rough. I've been running the STP gas
treatment every tankful, and that has helped a little bit. More on the
problem:

* erratic idle, sometimes stalling when go from high RPM's to slowing
to stop idle.
* erratic idle when warmed up, when the fan clicks off and the RPM's
drop, sometimes it drops to the stalling point. Lately, it's been
better since I've been using the cleaner to cleanout some of the carbon
deposits. Some info on the car.

* '93 Altima with 153k miles on it
* Distributor, plugs, wires, cap, O2 sensor all 1 year old.
* Engine definitely running rich - strong smell with 10% drop in
mileage
* No noticable problems at highway speeds

So if any tech or anybody knows what would be the cause of this code, I
would really appreciate the help. Thanks, Bill

it is saying the condition is rich and cant be resolved. are your
sparkplugs wet with fuel? leaking injectors. anything that would make
the mix rich.

willydog wrote:

Hi. I'm having a hard time troubleshooting code 45 from my ECU. I got
the code using a custom board I bought on ebay with the conzult
freeware version.

The idle has been running very rough. I've been running the STP gas
treatment every tankful, and that has helped a little bit. More on the
problem:

* erratic idle, sometimes stalling when go from high RPM's to slowing
to stop idle.
* erratic idle when warmed up, when the fan clicks off and the RPM's
drop, sometimes it drops to the stalling point. Lately, it's been
better since I've been using the cleaner to cleanout some of the carbon
deposits. Some info on the car.

* '93 Altima with 153k miles on it
* Distributor, plugs, wires, cap, O2 sensor all 1 year old.
* Engine definitely running rich - strong smell with 10% drop in
mileage
* No noticable problems at highway speeds

So if any tech or anybody knows what would be the cause of this code, I
would really appreciate the help. Thanks, Bill

Gentlemen - all good things. I know, I know. This is so old school, I
really need an ODBII vehicle, but they aren't "all that" either
probably.


I think the IACV is definitely sticking though too.. As a test - when I
turn the AC on, the idle goes up slightly - as expected. However, when
the compressor shuts off and the idle drops - it drops all the way to
zero and stalls. Am I smoking crack, or is this classic symptoms of
sticky valve? Based on experience - does anyone know what code ECU
throw with the classic "sticky valve" problem ?

Interestingly, I took the car out on a good 200 mile ride at between
80-85 MPH solid the whole way, so those injectors got a good nice
scrubbing. Now the car seems to be running *very well*, which is
interesting. I weened it off the cheapola gas treatements I bought in
bulk from SamsClub for $.75/ea. running 5 back to back before I noticed
a changable difference. It still idles high - like at 880 RPM, but it
does hold a good steady idle without hunting too badly. I can even
shift again into neutral without having it stall out. If I goose the
throttle, I hear what sounds almost like a sputter/backfire coming from
the engine area. (fuel injector?). I don't smell gas... so anyway I
don't goose the throttle anymore and am just hoping it's something
else.

I just want this car to get me another couple years. I've changed the
O2, distributor (twice - once including the aftermarket fiasco), plugs,
wires, cap, distributor, fuel filter, air filter. The only things that
I know of that need to be cleaned are:

* EGR (cleaned and replaced?)
* IACV - cleaned up and verified functional
* PCV valve (?)

Does the ground to the MAF problem just all the sudden start happening
like that? I've been reading other's symptoms and they don't sound like
mine.

On 12/30/06 8:05 PM, in article
1167530720.691340.163570 (AT) n51g20...oglegroups.com, "willydog"
<vette98dude (AT) yahoo (DOT) com> wrote:

Gentlemen - all good things. I know, I know. This is so old school, I
really need an ODBII vehicle, but they aren't "all that" either
probably.


I think the IACV is definitely sticking though too.. As a test - when I
turn the AC on, the idle goes up slightly - as expected. However, when
the compressor shuts off and the idle drops - it drops all the way to
zero and stalls. Am I smoking crack, or is this classic symptoms of
sticky valve? Based on experience - does anyone know what code ECU
throw with the classic "sticky valve" problem ?

Interestingly, I took the car out on a good 200 mile ride at between
80-85 MPH solid the whole way, so those injectors got a good nice
scrubbing. Now the car seems to be running *very well*, which is
interesting. I weened it off the cheapola gas treatements I bought in
bulk from SamsClub for $.75/ea. running 5 back to back before I noticed
a changable difference. It still idles high - like at 880 RPM, but it
does hold a good steady idle without hunting too badly. I can even
shift again into neutral without having it stall out. If I goose the
throttle, I hear what sounds almost like a sputter/backfire coming from
the engine area. (fuel injector?). I don't smell gas... so anyway I
don't goose the throttle anymore and am just hoping it's something
else.

I just want this car to get me another couple years. I've changed the
O2, distributor (twice - once including the aftermarket fiasco), plugs,
wires, cap, distributor, fuel filter, air filter. The only things that
I know of that need to be cleaned are:

* EGR (cleaned and replaced?)
* IACV - cleaned up and verified functional
* PCV valve (?)

Add cleaning the throttle body to your list.

Does the ground to the MAF problem just all the sudden start happening
like that? I've been reading other's symptoms and they don't sound like
mine.

Thanks. The throttle body was cleaned last year, but I'll have it done
again. I've got enough money sunk into this car that if I can drop
another $200 for another two years, that would be awesome. I mean I
baby this car. It still has the original rear drums, and the engine is
in mint condition from the engine degreasings I used to do in "the day"
with this vehicle.

If I bring it to my mechanic, what do you think is a reasonable quote
for the following work:

* dismantle and clean IACV, veryify correct behavior via component test
* check EGR valve - component test and clean/replace
* clean throttle body
* diagnose wet spark plugs and noisy injector.

I'll even let him use my consult card to pull codes. Most mechanics are
capable of using it, and the freeware software is very nice. I just
ordered a 10" cable for the laptop. If he would be receptive. I'm
thinking about 2 to 2.5 hours labor for the above work? (around
$150-$200 here). Am I going down the wrong path with this? Thanks.

be sure to let us know when the code pops again.

all the crap you mentioned ain't gunna fix it, I've seen this code more
times than I can count and I know what will fix it.


"willydog" <vette98dude (AT) yahoo (DOT) com> wrote

Thanks. The throttle body was cleaned last year, but I'll have it done
again. I've got enough money sunk into this car that if I can drop
another $200 for another two years, that would be awesome. I mean I
baby this car. It still has the original rear drums, and the engine is
in mint condition from the engine degreasings I used to do in "the day"
with this vehicle.

If I bring it to my mechanic, what do you think is a reasonable quote
for the following work:

* dismantle and clean IACV, veryify correct behavior via component test
* check EGR valve - component test and clean/replace
* clean throttle body
* diagnose wet spark plugs and noisy injector.

I'll even let him use my consult card to pull codes. Most mechanics are
capable of using it, and the freeware software is very nice. I just
ordered a 10" cable for the laptop. If he would be receptive. I'm
thinking about 2 to 2.5 hours labor for the above work? (around
$150-$200 here). Am I going down the wrong path with this? Thanks.