DTC 1128 and 1130

[slotsmd]

2002 Boxster S, 90K miles, 6 speed. History over last year included an IMS bearing failure and subsequent engine rebuild.

Symptoms: Car started throwing codes 1128 and 1130 a few weeks ago. Starting has always been very easy on this car, but along with the codes it became very labored- starts to crank very slowly for several turns then fires up. Idle seems slightly rough on occasion. I've also noticed an odd smell when I climb out after driving; hard to locate but most prominent in rear of vehicle and suggests something hot or burning.

So far: Cleared the codes the first time it happened, and they reappeared around a hundred miles later. Cleared them again, same result. Did some research which suggested MAF sensor might be at fault; replaced that and symptoms reappeared again. I've since cleared the codes again, and once again they've returned.

I've done a bit of research and it generally suggests MAF or an air leak into the oil system. Cap is on tight and AOS was replaced a bit over a year ago; I do seem to have a hard time getting the dipstick to seat properly and stay seated, but the last time I got the codes, I checked and it was down in it's receptacle with the O-ring in the neck where it belongs.

Does anyone have suggestions where to go with this next? I've searched this and other boards and coming up blank.

Thanks in advance.

John

[JFP in PA]

2002 Boxster S, 90K miles, 6 speed. History over last year included an IMS bearing failure and subsequent engine rebuild.

Symptoms: Car started throwing codes 1128 and 1130 a few weeks ago. Starting has always been very easy on this car, but along with the codes it became very labored- starts to crank very slowly for several turns then fires up. Idle seems slightly rough on occasion. I've also noticed an odd smell when I climb out after driving; hard to locate but most prominent in rear of vehicle and suggests something hot or burning.

So far: Cleared the codes the first time it happened, and they reappeared around a hundred miles later. Cleared them again, same result. Did some research which suggested MAF sensor might be at fault; replaced that and symptoms reappeared again. I've since cleared the codes again, and once again they've returned.

I've done a bit of research and it generally suggests MAF or an air leak into the oil system. Cap is on tight and AOS was replaced a bit over a year ago; I do seem to have a hard time getting the dipstick to seat properly and stay seated, but the last time I got the codes, I checked and it was down in it's receptacle with the O-ring in the neck where it belongs.

Does anyone have suggestions where to go with this next? I've searched this and other boards and coming up blank.

Thanks in advance.

John

While some have had success swapping out the MAF when they got these codes, normally they are related to either an intake/exhaust air leak or fuel starvation (low fuel pressure or delivery volume). I would very carefully examine intake system and all its hose connections (including the EVAP system) for possible leak points, and I would also look at the exhaust system ahead of the O2 sensors for leaks as well (air intrusion into the exhaust looks just like an intake air leak to the sensors). I would also run a fuel system pressure and delivery test to make sure the fuel pump is working correctly.

[flyingpenguin]

2002 Boxster S, 90K miles, 6 speed. History over last year included an IMS bearing failure and subsequent engine rebuild.

Symptoms: Car started throwing codes 1128 and 1130 a few weeks ago. Starting has always been very easy on this car, but along with the codes it became very labored- starts to crank very slowly for several turns then fires up. Idle seems slightly rough on occasion. I've also noticed an odd smell when I climb out after driving; hard to locate but most prominent in rear of vehicle and suggests something hot or burning.

So far: Cleared the codes the first time it happened, and they reappeared around a hundred miles later. Cleared them again, same result. Did some research which suggested MAF sensor might be at fault; replaced that and symptoms reappeared again. I've since cleared the codes again, and once again they've returned.

I've done a bit of research and it generally suggests MAF or an air leak into the oil system. Cap is on tight and AOS was replaced a bit over a year ago; I do seem to have a hard time getting the dipstick to seat properly and stay seated, but the last time I got the codes, I checked and it was down in it's receptacle with the O-ring in the neck where it belongs.

Does anyone have suggestions where to go with this next? I've searched this and other boards and coming up blank.

Thanks in advance.

John

While some have had success swapping out the MAF when they got these codes, normally they are related to either an intake/exhaust air leak or fuel starvation (low fuel pressure or delivery volume). I would very carefully examine intake system and all its hose connections (including the EVAP system) for possible leak points, and I would also look at the exhaust system ahead of the O2 sensors for leaks as well (air intrusion into the exhaust looks just like an intake air leak to the sensors). I would also run a fuel system pressure and delivery test to make sure the fuel pump is working correctly.

+1 on JFP's comments re. air leak. Hard starts are usually related to a bad crank position sensor and will hardly ever throw a code. I recently found a cheap BOSCH CPS on amazon.com (Bosch 0261210204 Reference Mark Sensor ). That fixed the hard starts, especially when warm.

Edited January 14, 2014 by flyingpenguin

[san rensho]

I just had a similar problem and it was a vacuum leak from the evap system. Theres a hose that connects to the throttle body that goes under the left hand intake manifold and connects to a solenoid valve. Pinch off that hose, if the problem goes away, then the problem is the valve.

[slotsmd]

I tried swapping the CPS with no improvement in starting performance. So far, the car has always started but I'm a bit leery of driving it anywhere for fear of winding up stranded. Is there a chance the hard starting is related to the codes? I haven't had the chance to chase the leaks yet due to other projects on the list at home, but I hope to try to go after it this weekend. I'll check the vac hose as you suggest, San Rensho, to get started.

[JFP in PA]

I tried swapping the CPS with no improvement in starting performance. So far, the car has always started but I'm a bit leery of driving it anywhere for fear of winding up stranded. Is there a chance the hard starting is related to the codes? I haven't had the chance to chase the leaks yet due to other projects on the list at home, but I hope to try to go after it this weekend. I'll check the vac hose as you suggest, San Rensho, to get started.

Have you checked your fuel delivery and pressure as I mentioned in my earlier post? Those codes are often related to fuel delivery problems, which would obviously cause hard starting.............

[san rensho]

I tried swapping the CPS with no improvement in starting performance. So far, the car has always started but I'm a bit leery of driving it anywhere for fear of winding up stranded. Is there a chance the hard starting is related to the codes? I haven't had the chance to chase the leaks yet due to other projects on the list at home, but I hope to try to go after it this weekend. I'll check the vac hose as you suggest, San Rensho, to get started.

Check the MAF values. If the MAF values are low, it's definitely a vacuum leak and i would suspect the evap valve under left hand intake. If the MAF values are up to spec, then look at the fuel delivery and pressure.

[slotsmd]

I haven't done these sorts of checks before. How do I go about checking MAF values and fuel delivery/pressure? I understand that looking for air leaks is a matter of methodically going over all the vacuum lines, and I've read up on various ways to look around, like using an unlit propane torch or the like. A professional would have a smoke device I gather, but that's too pricey for a one-time fix.

Thanks for any suggestions/guidance!

[JFP in PA]

I haven't done these sorts of checks before. How do I go about checking MAF values and fuel delivery/pressure? I understand that looking for air leaks is a matter of methodically going over all the vacuum lines, and I've read up on various ways to look around, like using an unlit propane torch or the like. A professional would have a smoke device I gather, but that's too pricey for a one-time fix.

Thanks for any suggestions/guidance!

The MAF values can be read by the Durametric software, PST II, or PIWIS. There may also be some aftermarket scanners that can see the MAF values as well (under PID values), but that varies by product. Fuel pressure and delivery are measured by connecting a fuel pressure test gauge to the Schrader valve test port on the fuel rail:

[slotsmd]

Finally getting a break from the honey do list and opened up my Bentley manual to see how to check fuel pressure. It says 2002 and later have a non return system that needs a special tester. Is that right?

[JFP in PA]

Finally getting a break from the honey do list and opened up my Bentley manual to see how to check fuel pressure. It says 2002 and later have a non return system that needs a special tester. Is that right?

Several companies, including Actron who made the unit pictured above, have adaptors that will fit the car. Cost is going to be in the $45-60 area at retail.

[slotsmd]

So the fuel pressure is fine and I have MAF reading of 3.5 or 3.75 with the engine idling (nicely l might add) at around 700 RPM. Problem is I can't track down a range of good values. Can you help?

[JFP in PA]

So the fuel pressure is fine and I have MAF reading of 3.5 or 3.75 with the engine idling (nicely l might add) at around 700 RPM. Problem is I can't track down a range of good values. Can you help?

What fuel pressure and delivery rates are you seeing? The MAF should be ~12-24kg/hr @idle and ~50-80kg/hr @3000 rpm.

[slotsmd]

Getting 13.5 kg/hr @ idle, 56 @ 3000 rpm. Fuel pressure@idle around 60 psi.

[JFP in PA]

Getting 13.5 kg/hr @ idle, 56 @ 3000 rpm. Fuel pressure@idle around 60 psi.

Did you conduct a fuel delivery rate test?

[slotsmd]

How do do that? Sorry a bit new to this type work.

[JFP in PA]

How do do that? Sorry a bit new to this type work.

Because of the severe fire hazard, you need to do this test carefully. It also helps to have someone help you while doing this test. Disconnect the fuel line at the fuel rail, and place the end into a measuring container. Switch the fuel pump on for 30 seconds, then turn it off. Minimum acceptable delivery volume is 850 mL or 0.9 US quart in 30 seconds. Be sure to properly reconnect the fuel line and test it for leaks after running this test.

[slotsmd]

Thanks again - and that will be this weekend's project. I've reset the CEL and will also see if I get a relight this week.

[slotsmd]

Back at it. My Bentley manual shows how to disconnect fuel lines from the rails but uses photos from a pre 2002, presumably 2.7l engine. It states procedure is similar for later models, but I'm not seeing the fuel line connection at the right rear as in the photo. Where would I look on my car? Do I just need to disconnect one rail?

[slotsmd]

It appears there is a single connection at each rail, but that these are just push on type. I'm worried about damaging those lines while pulling one off. They meet up at a single fitting from which a line (presumably fuel from the pump) leads forward under the passenger compartment,

[JFP in PA]

It appears there is a single connection at each rail, but that these are just push on type. I'm worried about damaging those lines while pulling one off. They meet up at a single fitting from which a line (presumably fuel from the pump) leads forward under the passenger compartment,

The cross over line from rail to rail should not be disconnected as it is a single use item. If you look at this diagram:

You want to disconnect line #8 either at the rail or beneath the car.

[slotsmd]

So... as you can see in the attached picture my engine is set up a bit differently. the part I described as a manifold can be seen, with a hose running to the left rail, and the end of the hose that runs to the right rail as well. The third line parallel to the one going to the left rail drops down and corresponds to 8 in the diagram you provided. So in order to avoid disconnedting the push on type hoses at the rails, I'll have to get under the car, remove the covers, and disconnect the line down there. Am I right to be concerned about detaching the hose from the rail?

[JFP in PA]

So... as you can see in the attached picture my engine is set up a bit differently. the part I described as a manifold can be seen, with a hose running to the left rail, and the end of the hose that runs to the right rail as well. The third line parallel to the one going to the left rail drops down and corresponds to 8 in the diagram you provided. So in order to avoid disconnedting the push on type hoses at the rails, I'll have to get under the car, remove the covers, and disconnect the line down there. Am I right to be concerned about detaching the hose from the rail?

The hose connection at the rail is a push on, single use barbed fitting that requires cutting and shortening the line to reuse it. Often, there simply is not enough line to accommodate this. So it looks like you need to go under the car.

[slotsmd]

Will, I won't be able to lift it for a couple weekends when I can get access to a friend's lift. In the meantime, I've broken down and got Durametric software. More info than my generic OBD II reader gave,

P 0410 Porsche fault code 80- Secondary air injection system cylinder 1-3

P 1411 Porsche fault code 208- Secondary air injection system cylinder 4-6

P 1128 Porsche fault code 360- Oxygen sensing adaptation idle range bank 1

P 1130 Porsche fault code 361- Oxygen sensing adaptation idle range bank 2

P 0507 Porsche fault code 32- Idle air control system exceeds limit value

Does any of this shed any more light?

[Ahsai]

Will, I won't be able to lift it for a couple weekends when I can get access to a friend's lift. In the meantime, I've broken down and got Durametric software. More info than my generic OBD II reader gave,

P 0410 Porsche fault code 80- Secondary air injection system cylinder 1-3

P 1411 Porsche fault code 208- Secondary air injection system cylinder 4-6

P 1128 Porsche fault code 360- Oxygen sensing adaptation idle range bank 1

P 1130 Porsche fault code 361- Oxygen sensing adaptation idle range bank 2

P 0507 Porsche fault code 32- Idle air control system exceeds limit value

Does any of this shed any more light?

All those codes point to vacuum leak. Maybe difficult without a smoke machine to pinpoint unless it's obvious.