99 T5 idles roughly, won't rev Topic is solved

[j-dawg]

99 T5, finished changing out the valve stem seals/cam seals/every other seal and gasket en route. The car's been sitting for the last few weeks because I haven't been motivated to figure it out, but I'm selling my Mercedes and want to get the Volvo healthy again so I have something to drive besides my Fiesta.

The car idles roughly (pap pap pap pap rather than brrrrrr, engine bouncing around on its mounts), steadily holding around 1000rpm but will rev only to about 2900. ETS light on, no OBD codes. My boost gauge shows me that the car is pulling only ~10 in Hg at that idle, compared to 20 when everything was running right.

ETM has a Sacer TPS, installed by ARD a year and a half ago, and got a fresh gasket when I put it all back together. I've smoked a couple of cigars into the intake manifold, sprayed ether at various potential leak points, disconnected each hose on the intake manifold and plugged it with my thumb. Can't find any more vacuum leaks. Compression is 170 +/- 5 cold on all five. Unplugged MAF, the thing doesn't even run. Timing sprockets and crank pulley line up correctly. VVT hub is at the end of its travel with the cams straight.

I noticed that when I go up and down the line unplugging injectors, the engine idle doesn't change on some of them, and when I put a screwdriver against them and press the other end to my ear, I don't hear a distinct click on each one. It's inconsistent which cylinders seem to "work".

If "G" is a good injector (strong click, unplugging changes idle speed) and "N" is a not-good injector (less-distinct click if any, unplugging does nothing to idle), here's what I got the first time I checked them as described above, from cylinders 1-5:
G N G N N

So I swapped injectors 1/2 and 3/4, but this time I got:
N G N G G

which is just the inverse of the original. A few more tries yielded similar results.

I bought five injectors and a fresh fuel filter. Swapped them in with the same G N G N N results. I haven't tried it again since last night, but it seems like there are two groups of cylinders (1+3, 2+4+5), and only one of them is firing each time I start the car, and it's not consistent which one. Does this sound familiar to anyone? I notice that that's the firing order of the engine, but I don't know what to make of that.

[wizechatmgr]

Sounds like the first time you swapped them the problem followed the injector. Now it sounds like it isn't the case.

If it were me I'd check all of the injection harness connectors with either a noid light or an oscilloscope to verify they're getting signal. Also double check the injectors with a multi-meter to verify the coil is good in each of them. Also test the ones you pulled off... This will tell you the electrical end is okay on the injectors - it doesn't rule them out entirely as they could be clogged or mechanically have issues...

Have you checked the ignition end of this?

[abscate]

Pull the plugs to evaluate the injectors. It's better to do this before swapping them.

I think I read from jimmy that limp mode involves disabling injectors so if your ETS light is in you need to deal with that first.

[j-dawg]

Sounds like the first time you swapped them the problem followed the injector. Now it sounds like it isn't the case.

If it were me I'd check all of the injection harness connectors with either a noid light or an oscilloscope to verify they're getting signal.

Neat idea! I'd never heard of a noid light before today. I got one from Autozone and tried it out. The car seems really set on running on three cylinders - if I pull the cable off an injector that's working, the car will find another to keep itself running. The exception was cylinder 2 - I never once saw the light flash on cyl 2. I also am not sure I saw it flash on 5, but I don't specifically remember it not flashing on 5. (I didn't take good notes.)

Also double check the injectors with a multi-meter to verify the coil is good in each of them. Also test the ones you pulled off... This will tell you the electrical end is okay on the injectors - it doesn't rule them out entirely as they could be clogged or mechanically have issues...

Plausible, and I'll check them, but given that I swapped all five and got exactly the same results, I don't think the injectors are the problem.

Have you checked the ignition end of this?

Swapped coils around, no change. There doesn't seem to be a correlation between specific ignition coils and a cylinder firing or not.

Pull the plugs to evaluate the injectors. It's better to do this before swapping them.

That's how I decided to swap them in the first place. Some weren't firing, but the noid light testing suggests that the ECU is not sending them a signal.

I think I read from jimmy that limp mode involves disabling injectors so if your ETS light is in you need to deal with that first.

This is interesting. My ETM has the Sacer TPS installed and showed no signs of a flaw before I took everything apart for the valve seals, so I don't think the unit itself is faulty. What else can trigger an ETS light?

[abscate]

The injectors get 12 volts constant, the ECU fires them by grounding. I'm not sure if a noid detects current flow or voltage?

[j-dawg]

The noid is just a bulb that turns on when it receives 12 volts.

[abscate]

Ah, so no good for testing injectors.

[j-dawg]

Nope. But with the testing I've done, I've concluded that the injectors are not likely to be my problem.

Does anyone know of a list of all the things that will trigger an ETS light? Obviously a broken ETM, I think a vacuum leak too, etc.

I did some more noid light testing yesterday. I plugged the light into an injector harness connector and started the car, unplugged the light, and then plugged the injector itself back in, observing results all the way:

- On cylinders 1, 2, and 4, the noid light blinked, and the car barely ran. Upon unplugging the light, the car began to run a little better. Plugging the injector itself back in made no difference.
- On cylinders 3 and 5, the car still ran like trash, but the light did not blink. Unplugging the light made no difference. Plugging the injector back in does not seem to have mattered either.

So injector 2 is on board now, and the car seems to arbitrarily select which cylinders it's not using. If I repeat the exact same procedure today I'm sure I'll get the same results but distributed across different cylinders. I'm getting no codes for cam or crank sensors, and upon inspecting the cam sensor, which I'd taken apart for the valve work, nothing looked too goofy.

[abscate]

Only one thing turns on the ETS light...the ECU

Ok, that was less than helpful.

Any fault condition in ETB software gets communicated to thenECU which trips a CEL or a ETS light accordingly. I don't think you get an ETS without a CEL normally. I have never seen details of the ETS software though. That would be a great find.

There are some VIDA descriptions of fault testing on the webs

[j-dawg]

I am such an idiot. About two years ago my ETM died, resulting in this thread. Replacement of the ETM was followed by a no-start which turned out - I only found after much struggle - to have been caused by an unplugged connector.

Tonight I had pulled the intake manifold back off and was poking at the ETM when I had a brain wave. Reached down to that same area and jostled a few connectors, looking for any that were unplugged. Squeezed one suspicious-looking connector and it clicked - it was apparently not plugged in the whole way. I immediately heard the whine of the ETM, which I realized only at that moment that I had not been hearing before.

Ugh. I put it all back together, started it up, and it ran perfectly. I looked for this one loose connector for literally months. Can't say if it was exactly the same one as had been loose last time, but knowing my life, it would be.