Chevrolet Colorado & GMC Canyon Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
New member. And so far the advice I've followed from this forum has been very helpful.

2007 isuzu i290 w/ inline 4 cylinder 225000 miles

Problem
Rough Idle. engine Surge when breaking


Things I've replaced
Replaced fuel injectors. I replaced all 4 with refurbished cleaned injectors. This had a significant improvement but it's still struggles

intake manifold gaskets
Cleaned the smudge from the intake.1mm of heavy oil caked to the inside.
cleaned throttle body. Caked
New Air filter... I found the air filter off the mount... Could this be the root cause after driving for a few hundred miles??


Spark plugs - 3&4 looked dirty but not terrible.

Fuel pump ( I started here unfortunately due to the past two vehicles having an issue here and learning the fuel filter is in the pump. I dumped $400 into a part that didn't help the problem but I have a cool picture of me using the crane at work to remove the bed provided access to the pump from the top side.)

Did a propane check for vacuum leaks and inspected hoses.


Before I keep throwing money at parts I wanted to ask for some help.
I'm a little bit concerned about the amount of oil it's burning,then again the aire filter was off and that may so be the problem. my next move would be ... Ignition Coil. O2 censor
 

·
Premium Member
Joined
·
3,995 Posts
New member. And so far the advice I've followed from this forum has been very helpful.

2007 isuzu i290 w/ inline 4 cylinder 225000 miles

Problem
Rough Idle. engine Surge when breaking


Things I've replaced
Replaced fuel injectors. I replaced all 4 with refurbished cleaned injectors. This had a significant improvement but it's still struggles

intake manifold gaskets
Cleaned the smudge from the intake.1mm of heavy oil caked to the inside.
cleaned throttle body. Caked
New Air filter... I found the air filter off the mount... Could this be the root cause after driving for a few hundred miles??


Spark plugs - 3&4 looked dirty but not terrible.

Fuel pump ( I started here unfortunately due to the past two vehicles having an issue here and learning the fuel filter is in the pump. I dumped $400 into a part that didn't help the problem but I have a cool picture of me using the crane at work to remove the bed provided access to the pump from the top side.)

Did a propane check for vacuum leaks and inspected hoses.


Before I keep throwing money at parts I wanted to ask for some help.
I'm a little bit concerned about the amount of oil it's burning,then again the aire filter was off and that may so be the problem. my next move would be ... Ignition Coil. O2 censor
When were the O2 sensors last replaced? Recommended interval is 100,000 mi. Deteriorated sensors can cause problems without setting the CEL. Defective coils usually cause misfires that will light the CEL. Having a scan tool that can read live data would be a huge help. Not sure what "off the mount' means regarding the air filter, but if it was allowing air into the intake, downstream of the MAF sensor, it could cause issues with the air/fuel mixture.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #3 ·
CEL is on

Not sure when the last maintenance was done to the 02 sensors, Ive owned the vehicle for 5 months .

I did an AutoZone scan and it said a misfire P009/ and replace spark plugs.

By off the mount. I mean the air filter, when I opened the compartment was not mounted so unfiltered air was being pulled into the motor. Probably adding to the build up I covered or worse.
 

·
Premium Member
Joined
·
3,995 Posts
I have a friend with a scan tool I'll need to enlist and I'll update once I get more info
Not sure what the code 'P009/' means. Haven't seen that before with a misfire. If the truck was driven in dusty conditions or for an extended period of time with the filter not connected it certainly could cause a number of issues, including internal wear.

If you get a scan, note the fuel trim numbers, both long term and short term. Get the readings at idle and at 1000-1500 rpm.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #6 ·
Sorry for the extended delay, I came down with a lil Covid but amd back in action, had the codes readand its not great

P0017
P1133
P0300
P0133

The idle issue is really bad at times
then it corrects and runs.. sometimes it stalls.

When I start and just it idle it will sputter out an stall.

Will replacing sensors be a possible way to resolve this?
 

·
Premium Member
Joined
·
3,995 Posts
The two DTCs (P1133 and P0133) are both for problems with the upstream O2 sensor. That's the sensor in the exhaust manifold. The PCM uses the signals from that sensor to control the engine operation. That could cause the symptoms that you have. Considering that you have no history for the truck, we can probably safely assume that neither of the sensors have ever been replaced. If they are both that old you should consider replacing them both. The two sensors work together and a new one upstream and an old one downstream could set some codes.

Yes, the upstream sensor appears defective and should be replaced. Suggestion, don't cheap out on these sensors. Either get OEM ACDelco sensors or some reliable aftermarket ones from Denso or Bosch.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #8 ·
Thanks for getting back to me again. I woke up with some hope that it may be the solution so I replaced both 02 sensors this morning.

It made some difference and there is a noticable improvement. It's still surging while breaking and switches into a rough idle. The rpms fluctuate when breaking and idle dipping from 1000 rpm to 500 rpm.

Are there any other sensors that could be the culprit?
 

·
Premium Member
Joined
·
3,995 Posts
You mentioned, several times, that the problem occurs while braking. Is this when the problem always happens or it just get worse when braking? What does the engine do when the truck is stopped at idle and you step on the brake pedal? If the problem then gets worse you could have a leaking vacuum diaphram in the brake booster. To check for that you could disconnect the vacuum tube going from the engine to the booster and plug the engine side. Don't drive the truck that way.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #10 ·
I checked the brake booster but it didnt effect the idle issue
For context issue with the braking was it would run fine while accelerating but when breaking it would surge and the idle speed would bounce up and down making it very uncomfortable.

I did some more digging on n p017 and P300 code symptoms and changed out the VVT solenoid along with an oil change . Idle problem solved

CEL is still on but I'm I haven't reset the battery.

In the meantime it's running so much better, pretty much everything that was replaced needed to be done and I'm very relieved thankyou for your help.
 
1 - 11 of 11 Posts
Top