half running engine.
 

My efi engine (3.3 with Carrera intake) seems to be running on one side only. Exhaust pipes are warm not hot where they are hot on the other. Engine runs rough obviously. It won't respond well and doesn't want to rev beyond 4500-5000 in neutral. This is all in the garage not driving. It could be bad o2, I did clean the newer spark plugs and do valve adjustment at same time as leak down on all cylinders. Run better directly following that. But it's back to running rough again. Does it seem like a fouling issue?
I did verify that injectors are working and ignition as well. Ideas?

Quattro, I forget, what ECU are you running? Are you running stock dist, coil packs, or CoP?

If your ECU has this function, test each injector (my Link G4+ has an individual injector test function, as well as an individual ignition channel test). I would start there... test the individual cylinder on the three that are not firing (both coil/ignition channel and then individual injector).

That should at least rule out fuel and spark.

Just read that you verified both spark and injectors.

Hmm, a bad O2 sensor would screw things up across the board, not just on three cylinders.
Have you checked your fuel pressure? Could be a regulator is going out (digging for stones here)...

Ecu is elecrromotive gt200. The gt 200 was the latest before they quit I believe. I could be wrong. but I don’t suspect that. I do suspect fuel. My regulator might be bad. Is that common?

I am not sure if it is common or not, but they do go bad... I am just thinking out of the box. I would get a guage on your fuel rail (if you do not have a fuel pressor sensor already installed) and check on fuel pressure while it is running.

If it is fuel related it could be lack of pressure ( bad FPR, pump going out, or a clogged fuel filter) or could even be trash that ended up clogging 3 injectors... I have seen injectors get clogged before) fuel filter should be filtering at the 10 -20 micron level nothing bigger.

Also, if it is fuel pressure related or clogged injectors, you should see that show up in your wideband as a lean condition during the time while it is breaking up

Here is a bit more info, car sat 6 years. I have cleaned the injectors but haven't thought about the filter. I have been wondering about the pump.
I think I'll swap out the filter and see if that helps first. Thanks!

On the subject of fuel filters... this right here is, absolutely without a doubt the BEST filter you can buy today! This is on a whole nother level of filtering (if you ever need to go this route) or for anyone else reading this and needs to get a better fuel filter. Let us know if the filter improves things :)

ID F750 Fuel Filter | Injector Dynamics

That's impressive

If it were me, I'd be going back to basics first, before assuming some electronic component mysteriously gave up the ghost.

How exactly did you test the injectors and ignition?

When you say one side is not running, you mean not at all? Like it's stone cold? I'm actually surprised the car would start or idle at all if that's the case. If it's "slightly" running as opposed to not running at all that implies a different set of potential problems.

With your EFI setup, how is ignition driven? Is it possible timing is way off on one side? Although, if you're getting fueling and even if timing is off 360 degrees, I'd suspect you'd get a ton of banking and fire out the back (btdt).

What is the wiring like for ignition? Do they all come back to common connectors? What is common for the non-running side, but not shared with the running side? Typically a coil pack would be shared between opposing cylinders, (1-6-2-4-3-5 firing order so 1+4, 6+3, 2+5) but don't know your setup. Are you running wasted spark?

Same for injectors, what's shared by the non-running side, but not with the running side? Do you have individual in-line fuel filters for each rail? Could there be something in the return causing an issue?

The header on one side isn't cold, but not hot enough for me to feel it's showing complete combustion or even lighting. I'm not smelling raw unburnt fuel.
I need to get my afr and egt gages back setup so I can tell more. I have a new fuel filter coming.
As for how I tested ignition and injectors:
The plugs were out and visually verified to show spark.
The injector plug was connected to a test light and each one lit. I also removed all injectors and cleaned with voltage across them.
While I did all this I also leak down tested the engine and got great results.
I didn't compression test. But I suspect leakdown would indicate any damage that might show a bad compression.
Also I cleaned and gapped the "new" plugs and right after this it did seem to run better initially. I suspect a screwy 02 sensor or tune. I might have fouled plugs again but I'll have to get back in there.

you may want to edit your initial listing and start with the car sat for 6 years .. could be anything fuel related but seeing as its one side only and i know nothing about EFi.. i would consider checking your cam timing on the side that is not firing correctly that tensioner may be failing. they have been known to fail after sitting for long periods of time just a few degrees is enough to make it run awful and still not smash your valves into your pistons .. i wouldn't start it again until you find the smoking gun on the fuel or electrical side of the system. Or confirm its not a cam timing issue or

keep us informed.

Regards Ned

OMG I should delete this whole thread if that's the case because there is more info.
7 years ago I spun and the engine most likely went backwards. Would the leak down not indicate off cam timing?
Engine is fresh but I'm unsure about the tensioners.

This is telling.

You've removed the plugs as well and would have seen if you were flooding, therefore my feeling is the issue is fueling.

sounds like the injectors were tested out of the car, without using the ECU or harness in the car. Problem could be here.

If the engine is turning, the ignition is firing and the injectors are injecting I would expect to get something, backfires, fire, something. But not only are you not getting that, but you aren't smelling or seeing unburnt fuel.

That tells me the injectors are not injecting. Doesn't mean the rest is working correctly of course.

If you are comfortable the injectors work on the test setup, I'd first make sure I'm getting fuel flow/pressure in the rail on the bad side. Is it the same as the other rail? Then I'd try and test the injectors in the car somehow. Idk if you can direct them into a baby bottle or something and crank the car.

A leak down will tell you if you have a bent valve, bad rings, etc. The only way I know how to check cam timing, is just to run through the cam timing procedures all over again....

So, you checked the function and operation of the injector by using a Noid light, correct? I have only done that once, on a different car. Does your ECU in the laptop, have a test function for the injector drives (injector channels)? If so, you could turn it on ( after disabling the fuel pumps) and actually here the injector fire. On mine, I hit the test function on cyl #4 ( injector channel #4) and walked back and it pulses the injector about 5 times a second. That was clearly audible from the back of the car.

And did you say that you have a working wideband o2 sensor with a gauge on the dash that you can look at? I am trying to remember what you said in pervious post. I am using my phone, and for some reason it is being a real PITA to scroll and try to find all of this previous thread. Sorry if you already answered this...

Brad

My car was taken down to nearly a tub minus the engine out and wire harness. I backdated it and paint. That’s all done now and after finishing my headliner I’ll be putting all back together.
Once all back together. I’ll remove the engine and do the cam timing. I’d like to swap out the cam things a good time to do that.
Before I do all that though I’ll check the plugs again and determine if indeed its not running correctly from cam timing. I need to make sure the time isn’t causing this.
I do have afr and egt gages but they’re in a console that is not installed. I could install it. I should. But I also want to add egt for each side but I can tell by touch that it’s off.
Again I’ll be checking plugs tomorrow.
As for setup I have electromotive which has worked well. I have sequential injection and coil on plug. I also am using a cam sensor for ignition to get away from wasted spark. It’s been a while now but my thought was to go more accurate and I didn’t like the name wasted spark lol. But..this change was not right away and I need to make sure I’m not using a file that was made before I went away from wasted spark. I assume this change would make the engine run differently. Maybe even with these sorts sSymptoms. So much to figure out with no experience on the subject. I need to find out if the system can check function. Richard from Clewett did mention check engine codes. I don’t know where or how to do this yet. The manual doesn’t mention it. Or I haven’t seen it yet.
Anyway.

So i got what i assume is the same trigger wheel and crank sensor. I had a very similar symptom in my setup, ran like ****. Then a smart fella on msextra checked my tune and notices my crank speed was set to 200. So that was so low that it sounded like it ran but just kind of didn't, then died. Anyway, check cranking to above 400. Also BTDC# is about 55 degrees if not adjusted automativally. Share a tune?

I gor megasquirt so if nothjing of this is applicable, then have a beer on me :)

I have the 60-1 trigger wheel and sensor mount and vr sensor from Clewett btw. Also try doing a log. That is very helpful.

Also, im drunk as sheets in bangkok. Hahahahaha

Tonight I tried again. First though I checked the plugs for fuel or whatever else they said. They were dark but that’s not too bad since the car isn’t tuned at all really. At least they weren’t wet with fuel. They did smell a little tho. Whatever I cleaned them with wore brush and put em back. What the hell I started it. Seemed better again. I decided to try volumetric efficiency tuning and that seemed to further tune it smoother still. I changed the tog a couple points and that helped more. I’m here punching buttons here. I still may have a timing issue but it’s close. Close enough to enjoy the sounds and smells.
But it flames out the exhaust far too easily. I’ve never seen that on this car.
I could use some help. Whoever can help me with this situation I’d love to chat over the phone. Pm me and we can make an appointment?

Fouled plugs?

"But it flames out the exhaust far too easily. I’ve never seen that on this car."

Sounds really rich to me! I would get that afr gauge hooked up and see what is going on. doesn't efi monitor afr?
I'm just an old CIS guy so that's about all I know.