Near Catastrophic Engine Failure
Near Catastrophic Engine Failure
This was a very close call.
Since putting about 1000km on my new motor ive been starting to get heavier
with my throttle application and when I reached 1100km I decided to give it
some in a straight line. I went to a private bit of road and pointed my car
down the straight. I revved it up a bit and took off in first, revved it all the
way out and shifted into second, rev it out and shifted into third but as soon
as I did that the check engine light came on the power started dropping so I
pulled over where the car stalled on the side of the road... At this point
I was sh*ting myself. When I tried to start the car again the revs would
move up around 2000rpm and then drop to above idle and jump up and down
sounding like a rotary. I plugged in my laptop to see what the engine was
doing and it was reading different parameters seemingly all over the shop. The
warning lights were on and there was nothing I could do there so I left the
car there and went home.
When I got home I read through the workshop manual and printed out the
procedure for manually retrieving the OBD codes, grabbed a watch with a second
hand and went back to the car. The process for getting the codes out manually
is very specific and has to be timed to the second or it wont work. Turn the
ignition to on, wait three seconds then push the throttle all the way open
then shut 5 times in 5 seconds, then of for 7 seconds then on for 10 seconds,
then off etc. After countless attempts of trying to get this to work using the
second hand on a tiny watch it finally worked and the codes 1121 and 1122 came
out. With the workshop manual I was able to figure out these are related to
the DBW actuator / DBW system. When I read this I thought great, there is a
UTEC firmware upgrade for the DBW processor in the UTEC as some people were
having issues with the car going into limp mode, which sounded like what I was
experiencing. So I downloaded the latest DBW software and ripped apart the
dash so I could get to the UTEC. With the dash apart I grounded myself,
flicked the correct switches, hooked up the laptop and reflashed the firmware.
When that was done I cleared the codes from the ECU and tried starting her up,
straight away the same issue. After that I thought I need to work out if it is
a UTEC issue or something else, so I disconnected the battery, grounded myself
and pulled more of the car apart to get the stock ECU and UTEC out. I
disconnected the UTEC, reconnected the stock ECU, reconnected the battery,
cleared the codes and tried again... the same issue. So I now knew the problem
was not UTEC related, but could now be a myriad of other things to do the
stock ecu, electrical or mechanic systems.
The 1121 and 1122 codes have a number of pages and things you can do if you
have a Nissan Consult, which I did not so I decided to check the mechanical
systems involved. I checked all the vacuum connection points on and around the
intake manifold, then the intake system apart to get to the throttle
body. As soon as I had the intake piping off I could see the throttle body and
thought what the f!@k is that. There was a large dark piece of rubber right
across the throttle body half on the engine side and half on the intake side.
I pushed the butterfly and pulled this piece of plastic out. When I had it in
my hand I knew straight away what it was and I couldn't believe that it was
there. If it had gone into my engine that would have been it for my new motor
and we would have been questioning what caused it to go, assembly, parts,
tuning, etc.
After removing it and assembling everything the car ran great.
$2 for the person who can tell me what it is...
Since putting about 1000km on my new motor ive been starting to get heavier
with my throttle application and when I reached 1100km I decided to give it
some in a straight line. I went to a private bit of road and pointed my car
down the straight. I revved it up a bit and took off in first, revved it all the
way out and shifted into second, rev it out and shifted into third but as soon
as I did that the check engine light came on the power started dropping so I
pulled over where the car stalled on the side of the road... At this point
I was sh*ting myself. When I tried to start the car again the revs would
move up around 2000rpm and then drop to above idle and jump up and down
sounding like a rotary. I plugged in my laptop to see what the engine was
doing and it was reading different parameters seemingly all over the shop. The
warning lights were on and there was nothing I could do there so I left the
car there and went home.
When I got home I read through the workshop manual and printed out the
procedure for manually retrieving the OBD codes, grabbed a watch with a second
hand and went back to the car. The process for getting the codes out manually
is very specific and has to be timed to the second or it wont work. Turn the
ignition to on, wait three seconds then push the throttle all the way open
then shut 5 times in 5 seconds, then of for 7 seconds then on for 10 seconds,
then off etc. After countless attempts of trying to get this to work using the
second hand on a tiny watch it finally worked and the codes 1121 and 1122 came
out. With the workshop manual I was able to figure out these are related to
the DBW actuator / DBW system. When I read this I thought great, there is a
UTEC firmware upgrade for the DBW processor in the UTEC as some people were
having issues with the car going into limp mode, which sounded like what I was
experiencing. So I downloaded the latest DBW software and ripped apart the
dash so I could get to the UTEC. With the dash apart I grounded myself,
flicked the correct switches, hooked up the laptop and reflashed the firmware.
When that was done I cleared the codes from the ECU and tried starting her up,
straight away the same issue. After that I thought I need to work out if it is
a UTEC issue or something else, so I disconnected the battery, grounded myself
and pulled more of the car apart to get the stock ECU and UTEC out. I
disconnected the UTEC, reconnected the stock ECU, reconnected the battery,
cleared the codes and tried again... the same issue. So I now knew the problem
was not UTEC related, but could now be a myriad of other things to do the
stock ecu, electrical or mechanic systems.
The 1121 and 1122 codes have a number of pages and things you can do if you
have a Nissan Consult, which I did not so I decided to check the mechanical
systems involved. I checked all the vacuum connection points on and around the
intake manifold, then the intake system apart to get to the throttle
body. As soon as I had the intake piping off I could see the throttle body and
thought what the f!@k is that. There was a large dark piece of rubber right
across the throttle body half on the engine side and half on the intake side.
I pushed the butterfly and pulled this piece of plastic out. When I had it in
my hand I knew straight away what it was and I couldn't believe that it was
there. If it had gone into my engine that would have been it for my new motor
and we would have been questioning what caused it to go, assembly, parts,
tuning, etc.
After removing it and assembling everything the car ran great.
$2 for the person who can tell me what it is...
Bingo, there are two rubber pieces in the stock air box. I ripped the other one out when I found the one around my throttle body. I would recommend people check theirs to make sure they arent coming off as they will blow your motor if it goes in.
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