Rhys19

My car has a big issue been this way for the past week if I start the car it literally constantly misfires nonstop.

I replaced all my plugs coils and wires not even 1k miles ago.

I also pulled my plugs and noticed that their wet (Smells like gas)

I don't have any codes other than these:
System Bank 1 Too Lean
Intake Manf Tuning Valve Stuck Open

What I've done so far
Replace MAF sensor
Replace Coils
Replace Plugs
Replace Plug wires
Cleaned the Crank Angle sensor/ESS and even tried replacing it.

Some data i've written down:
AFR at idle: 18.88-19.32
AFR when driving normal: 14.2 - 16.3
RPM: very hard idle (Jumps from 600-845)

I am honestly confused on this I've tried everything I could think of to try and solve this any ideas?
STFT: usually around 2.5 to -7.2

XDragon8

Im not a pro but think you have an issue with one of your trailing coils/ wires/ plugs.
What coils/ wires and plugs?
It is possible that one of your coils was dead on arrival. If they are not factory or very well known aftermarket brands then that is likely your problem.

BigCajun

iTrader: (1)

Did you search for the specific code troubleshooting fixes?
The tuning valve sounds pretty specific, not like a generic misfire code.

Shaozhou Zhang

What’s your MAF reading at idle? Should be 5-5.5G/S. Anything lower than a 5 means you have a vacuum leak.

Rhys19

I thought so at first but after examination they all are sparking I even tried replacing both trailing with new coils as for the wires, the wires are brand new even tested them with a spark tester. the plugs were fuel fouled aswell (Could be from the high AFR)

Yes I did try searching that intake tuning valve code but nothing really shows up.


So my maf was replaced if you read the post as that was part of the issue if I try putting my old maf back it doesn't start and throws a maf circuit high code.
as for what the maf is reading at idle, I'm seeing it jump from 4.8 - 5.5
I've already checked all the common places for a vacuum leak aswell. however There are 2 big hoses coming off the intake tube (STOCK INTAKE) I can trace those and see if those came off at the other side.

Loki

iTrader: (1)

The tuning valve stuck open is the SSV (probably). You can try to turn it by hand to see if it's sticky. To clean you'll need to do a bit of disassembly of the intake manifold. If you search for the code number (as opposed to the label) you should find a guide here.

the other 2 valves can also be problematic but are harder to access. They're called APV and VDI. Usually it's the SSV.

Your AFR isn't high, it's low (lean). So fouling the plugs is...weird?

Rhys19

So I did take a peak at my ssv, and noticed that bar from the vacuum chamber(The round vacuum actuator on the ssv) that connects to the valve is disconnected???? I connected it back but it slides right off took it for a rip and the code seemed to have gone to inactive but after a few drives it came back (So i'm positive it's the SSV)
The vdi moves freely though

also I have never had my injectors out not to mention my car worked fine before just all of the sudden it's doing this.

Could it be my front o2 sensor maybe? it's a 2004 and everything on the exhaust is stock so maybe it's going out?
I mean I honestly can't think of anything else.

Rhys19

I'm also aware of the disassembly to get to the ssv I've cleaned it once before about maybe a year or 2 ago.

Loki

iTrader: (1)

There was a problem with the SSV actuator in early years that sounds a bit like your case. It would get loose and rattle, though I haven't heard of it falling off entirely. Not sure if you can get away with just replacing the actuator arm or the whole SSV.

​​​​​​
I don't think it's your O2, O2 sensors don't fail by reading wrong but consistently. They fail by not reading or fluctuating wildly.

One other thing to check are the jet air ports on the intake manifold. Those specifically help stabilize the idle and if vacuum hoses aren't connecting them to the intake, you might get what you're seeing.

Rhys19

Are the jet air ports the service ports on the side of the intake manifold by the windshield washer reservoir? Or somewhere else? As those ports are covered by a cap.

As for the ssv if I re attach the arm the idle stays the same, it tries to stall but catches itself.

And yes I've already done the 20 stomp reset and driving a couple times to relearn fuel trims.

Loki

iTrader: (1)

Jet air is a single nozzle below the service ports that should connect to the intake before the throttle.

Rhys19

I traced both lines from the intake one goes to the oil metering nozzle and the other goes to a metal line I haven't traced the metal line yet

Rhys19

So I looked up a vacuum diagram and checked all of the lines, I literally cannot find any that are split, cut or that are disconnected, I even tried reseating the Oil injector one, and the Jet air nozzle but still no result.

I checked my crank sensor again to see if it was dirty but still sparkly clean.

I'm 100% confused on what's causing this

new data captured:
About the same honestly
MAF: 4.8-5.0 at idle
AFR: 19.85-20.85 at idle
AFR doing 75mph at 3k rpm: 14.35
Long term fuel trim: 2 (This was after the 20 stomp and 2 drive cycles)
Short term fuel trim: 7.03
Fuel trims were captured around 75mph at 3k rpm

Other data:
Load 28%
RPM: 847
Coolant: 206*F
Rear o2 sensor voltage: 0 (Front is null but I assume that's because it's an AFR sensor)


Here is some old data I captured when the issue first arrived:
AFR: 18.24
LTFT: 22.66%
STFT: 25.00%
Revs: 817RPM

The shop up the road can do a smoke test for about $50 diag fee, should I have them smoke my intake and see if it's leaking?

Loki

iTrader: (1)

Hmmm what rpm is idle for you? 4.8-5 grams/sec of air is in the right ballpark for 800rpm. A touch low, but the computer should be able to compensate for small leaks with fuel trim. But 20 AFR (which is basically as lean as the sensor can read) with small trim values makes no sense at all. Do you see fuel system status? Does it show open loop or closed loop when you idle? My guess is it's running open loop (not watching the O2 sensor) instead of closed loop as it should, for some reason.

If it was me, smoking the intake wouldn't be high on my list given this info, but it might still be helpful to buy diagnostic time to see what they can come up with. As long as they don't walk you into replacing parts on a guess.

However the old data you show is classic vacuum leak, too big for the computer to compensate (fuel trims are maxed). Do you have the airflow grams/sec from that time?

Rhys19

I used to see it idle anywhere from 945 RPM steadily If I remember right it was pretty damn close to 1k
as for if it's running open loop here's what the scanner says:
Fuel System status:
Closed Loop. Using 1 O2 Sensor (feedback fault) (Rear o2 sensor is throwing a code since it's bad)
if I let off the accelerator it will then go to Open loop due to engine load.

As for the old data the best I can find from my screenshots is
maf: 4.0
RPM: 847
Load: 28
Coolant: 206*F

if I remember right that was after a drive which is why the coolant is around 206 if I let it warm up to normal temps without driving it sits right around 188-190*F

Loki

iTrader: (1)

Ok so the old data is definitely vac leak. 4 grams is way too low for 857 rpm. So that original issue checks out.

Idling near 1000 rpm on 5 grams is also no good, so probably the same reason. But, the reason it's idling that high to begin with is a clue. Your usual cracked hose doesn't change the idle in a big way, just offsets the airflow measurement. To affect the idle, you're looking for something bigger: UIM not attached to the LIM correctly, crack in the manifold. Was the manifold removed before when issues started?

Did you check vacuum accumulator box under the UIM that feeds the valve solenoids?

Smoking the intake makes more sense now too.

Rhys19

By manifold you mean the UIM? the actual intake manifold was never ever taken off, the UIM however multiple times but I made sure the bolts were tight, I've also inspected the UIM and vacuum accumulator and I don't see anything that would cause this, thought the gaskets look a bit smashed but I'd like to smoke test it to see where it's leaking before I go buying gaskets and what not.

Loki

iTrader: (1)

Alright. Smashed gaskets could do it. You could run your finger or a wet rag around the joint to see if changes the idle. Should be pretty apparent.

Rhys19

I'll try that tomorrow, it's really late now, will let you know!

worst case scenario I can just get a smoke tester from amazon smoke it then return it or just have my shop literally on my road test it for $50 (which is a diag fee meaning I can just have them run a diag on it) however this shop isn't a ROTARY SPECIALIST, although they've had my car for inspections and they seem to have a good amount of knowledge about them, it's a family owned business.

Fair notice: if you've been on my other post you should know this 8 has been overheated a couple of times I should note it happened again when my waterpump belt snapped I pulled off the road as soon as I saw the gauge hit past normal, but after the car was shutoff the gauge was like already near H: it's been fixed and driving but I don't have any bubbling in my coolant reservoir nor do I have any white smoke and still starts pretty quick on cold, hot starts are eh maybe 2-3 seconds long but no more than that.

I will be getting a compression tester here soon still waiting for it to come in the mail but I don't think compression could be the idling issue honestly it just doesn't sound right.

Loki

iTrader: (1)

Yeah there's too much other stuff going on to blame compression. This isn't a rotary problem per se, any MAF-based car is sensitive like this, so your shop should be able to help narrow it down. Amazon returns mostly end up in the landfill, so I'd try and avoid that route.

Rhys19

Ya, I might send it up there, I mean there shouldn't be any trouble because technically the only thing rotary based as far as I can tell, is literally just the engine (like the combustion chamber, etc) everything else on the outside I pretty much see on any car.

I'll give em a call tomorrow and see if they can take it in and diag it.

Think I should still test compression after all those hot incidents to see how long I even have left? that and afaik it's a replacement motor with a reman tag I have no idea what it's compression even is.

Loki

iTrader: (1)

Never a bad idea to know if your engine is healthy. Rebuilds aren't cheap, might take some financial planning if one is needed.

Rhys19

Fair, Pretty good idea though, I'll just buy one and keep in my trunk

Rhys19

So an update I bought a can of brake clean except this time I tried where the uim meets the lim, and what do you know, spray break clean around some parts and the idle stabilizes for a split second, to .make sure it wasn't a flunk I sprayed a little bit more and again same thing I think I found my vacuum leak.

Rhys19

So I took some data while idling it's been awhile since I last used it I also put new plugs in it.