Ifly951

Hello everyone I am looking for new suggestions on what the problem is.

Just 3 days ago the car was spooling nicely and everything was normal for this car. Then yesterday upon starting the car it idled very rough and stumbled around acting like it was almost out of gas. I thought this was because of low fuel and that being it, so I put in 9 gallons of fuel. Car idled ok after a 1/4 mile but now when I go to full throttle the car just has no power after 5000 rpm and basically sputters. It's not making any boost after that and it's best to get off the throttle.

I have checked all vac lines and hoses. Checked Turbo to intercooler charge pipe for cracks same with Maf intake pipe.

I pulled spark plugs (look rich) and put in my spare set of NJK BPR7ES plugs. No change.

I switched out coil and drove the car. Car was a little smoother off boost. On boost in 1st gear car spooled and then surged, then spooled and surged again. 2nd and third gear the car did the same no power after 5000 rpm. Basically no improvement.

Next I put my fuel pressure gauge on. Reads 42 psi at idle and 42-44 psi when giving it some throttle.

Last I checked bypass valve and it opens with nothing blocking either side.

I am stumped.

Car has Rogue M-tune, 50 trim rebuilt Turbonetics (200 miles on rebuild) and Tial 38 mm wastegate.

I am trying to deduct if it's fire/ignition related or fuel. Plug wires are due for a replacement. Or is this the KLR preventing damage to the engine because of something else?

CyCloNe!

reference sensors been checked? maybe a dme computer fault? checked TPS?

dmcampbell

My bet is that if the fuel pump is ok, the MPS you installed with the M tune is sensing an overboost condition resulting in fuel cut off/ignition retard. Joshua would know for sure though.

Rogue_Ant

The issue only happened after running the fuel tank low?
If so, replace the fuel filter - you might have sucked up a bunch of sediment...

Ifly951

The car was very low on gas and stumbling as I drove from my place to the gas station about 300 yards away.

Car drives fine when not pushing it, so maybe that is the issue. I will replace fuel filter after ordering one Friday and post the results.

CyCloNe!

there fixed

Ifly951

Follow Up.

Put in new fuel filter. Car is running normal now when not in boost. Before it stumbled and was very rough. Car seems to boost well when it's in warm up mode or the first 5-10 minutes. After it's warmed up the car does not boost very well, if at all in higher gears.

I will check the reference sensor. I occasionally get a little tach bounce, but have not had it in awhile.

Maybe the injectors are a little fouled now too? They are 80 lb ones with 200 miles on them tops.

Spidey944

my guess is the WOT part of the TPMS is not working or it's misadjusted. In my 14 years of wrenching I have seen a bad fuel filter cause issues twice. That's it. So the filter probably didnt make much of a difference.

Ifly951

I just want to clarify this(tpms) is the Throtle Position Sensor, right. Mine does not look like it is the original unit (replaced). But from what I always read this part makes a big difference.

Yes mine clicks and "seems" to run, but maybe not.

hieric

hi, Ifly951. My car has same problem now. Please let us know if there is any update information. thanks a lot.

jlturpin

Bad fuel?

Tom M'Guinn

Boost-based misfires are often caused by poor ignition -- bad wires, cap, rotor, or plugs. I'd made sure all those parts are in tip top shape before chasing other causes...

95ONE

My car started doing the same thing before going to MoTeC. Two thousand dollars was spent on other things trying to fix the problem. Too embarrassed to explain the cost. 3 engine computers were part of that.

My symptoms... EXACTLY the same as yours.
Bad news.. It was that my wiring harness had fried. some spots worse than others. It was from the stupid fan resistors. Those thick wired were burning through every other wire.
My wideband was showing the motor was just going very lean. So lean it couldn't get out of its way. It was ok.. not great on warm up. Some days it would idle o.k., but mostly like crap. Like the TPS sensor was disconnected. IT actually idled BETTER when it was disconnected.

I'm sure there is a more specific electrical short that was causing this exact condition,and it might be ONLY that exact problem for you. But for me, the larger problem was the wires were just starting to short out from the bad wires under the dash. More problems would have shown up later. I'm very glad to be rid of the crispy 25yr old wiring.

- lighter note.. Did you know the Fuse panel and all wires attached directly to it weighs a full 15lbs!?

toddk911

How much are Motecs costing these days?

How hard to install and tune Motec system?

Ifly951

My only update on this was that I have pulled the DME apart to check if maybe the chip was a factor in all of this. But it is seated just fine. As far as bad fuel. I thought about that, but have added more fuel (from a different place)to the car while trying to diagnose what is going on.

My plan is to buy new plug wires, cap and rotor. See if this does anything as they could use a replacement.