Jump to content
SAU Community

R33 GtsT No power and backfiring after Cam Belt change

Skaith4224
 Share

Recommended Posts

joshuaho96 Veteran

joshuaho96

Posted
Posted

Definitely don't parts cannon your way out of this. As a part of the cam belt service the CAS has to come off. I would look very carefully at the CAS and the bits that it interfaces with to verify that nothing is worn or has play. If for whatever reason it was binding against the cam drive that could cause the symptoms you're seeing.

If you're worried about plugs pull them and inspect them. It's not a modern car where pulling plugs is a massive ordeal so it's fine to put used plugs back in if there's nothing wrong with them.

Skaith4224 Apprentice

Skaith4224

Posted
  • Author
Posted

Hi All,

 

Still trying to get my hands on a CAS sensor. Seems people in my area are being a little quiet at the moment and the local get together has now been cancelled due to some BMW drivers getting too excited at the meets and ruining everything :<

 

Anyway, I've been tinkering and tried a new software that may be able to read the ECU. Unfortunately i've not been able to get it to work yet however it did make the check engine light do some funny things.

Out of curiosity I performed the bridge trick to get the code and it has now started giving me 3-4 knock sensor.

 

I reset the ECU and start the car, idle for about 30 seconds and check the code again. Knock sensor again.

 

As this seems to be a permanent thing but the engine sounds great I've looked into temporary bypassing the sensors to see if this stops pulling timing and dumping fuel. However I'm finding it difficult to do this.

I've checked the sub loom that has good continuity so I don't think it's that, maybe the main loom?

Checking forums I'm supposed to use a resistor between the knock sensor cable and a ground point. I used a 470kohm resister at the plug end and now at the ECU loom but I'm still getting the code.

 

Does this mean I'm not doing it correctly/incorrect resistance or is there other things that can cause code 3-4?

 

On a side note, I did see that the speed sensor wire at the ECU was broken so fixed that. Not sure if it's changed anything though.

 

Thanks.

joshuaho96 Veteran

joshuaho96

Posted
Posted
On 11/25/2021 at 7:19 AM, Skaith4224 said:

Hi All,

 

Still trying to get my hands on a CAS sensor. Seems people in my area are being a little quiet at the moment and the local get together has now been cancelled due to some BMW drivers getting too excited at the meets and ruining everything :<

 

Anyway, I've been tinkering and tried a new software that may be able to read the ECU. Unfortunately i've not been able to get it to work yet however it did make the check engine light do some funny things.

Out of curiosity I performed the bridge trick to get the code and it has now started giving me 3-4 knock sensor.

 

I reset the ECU and start the car, idle for about 30 seconds and check the code again. Knock sensor again.

 

As this seems to be a permanent thing but the engine sounds great I've looked into temporary bypassing the sensors to see if this stops pulling timing and dumping fuel. However I'm finding it difficult to do this.

I've checked the sub loom that has good continuity so I don't think it's that, maybe the main loom?

Checking forums I'm supposed to use a resistor between the knock sensor cable and a ground point. I used a 470kohm resister at the plug end and now at the ECU loom but I'm still getting the code.

 

Does this mean I'm not doing it correctly/incorrect resistance or is there other things that can cause code 3-4?

 

On a side note, I did see that the speed sensor wire at the ECU was broken so fixed that. Not sure if it's changed anything though.

 

Thanks.

If this is a two wire knock sensor you should verify that there isn't a short to ground. Also make sure you don't have a marginal connection by tapping the wires while you test their continuity. If you have solid contact with the terminals the whole time but you see resistance changing as you move the wires around it's possible that there's a break in the line that is just staying connected part of the time.

Dasmbo Collaborator

Dasmbo

Posted
Posted

Hi i had similar problem backfiring and knock sensor showing problems turned out my coil packs were mostly stuffed try firing up the engine with the coil cover removed and look at the coil packs with the engine running at night with no light and see if your coilpacks are are shorting to the engine mine were like a mini lightning show shorting out every where new coil packs and plugs gapped to 0.8mm and cured my problem is your car a series 1 or 2 if series 1 could also be an igniter prob your boosting prob could be the hose on the high /low boost controller hope this helps 

Skaith4224 Apprentice

Skaith4224

Posted
  • Author
Posted (edited)

Hi All,

 

Quick update. Still can't bypass the knock sensors so giving that a miss for the moment.

 

The car is a series 2 so simple coil setup. Wanted to check tonight but the car now won't start due to the fuel pump.

 

I'm now all colours of confused and think I'm getting way out of my depth here.

 

Today I had a bit more of a fiddle with the sensors by grounding them on the ECU ground and a few other things. no change. Checked continuity from the ECU cable to the sensor plug and all seems connected and getting good signal.

 

Went for a quick drive to my mothers today to say hi and when trying to leave, the fuel wouldn't prime again. nothing from the pump. The relay clicks but nothing.

I fiddled with the relay briefly and it came back so I went on. Later the same thing happened but took a little more trying but finally primed.

Now I can't get the pump to work at all. It's now very cold so maybe the temperature is not helping things?

 

This is my third pump as the original one that came with the car was aftermarket but sounded intermittent so I changed it with a walbro pump. That failed within 2 weeks so I went back to the old one.  By this time I had read up on the relay hotwire method to get correct voltage to the pump but I guess it was too little too late. That then failed and left me stranded. Ordered a 3rd pump, "quantum 340LPH pump" that has decided to stop today. I'm going to be checking wiring tomorrow however I'm now wondering if this could all be related.

 

To summerise:

 

Car was running okay, needed some leaks to fix and replace some consumables like the plugs etc however wasn't too bad.

Took it to the garage to replace the water pump as it was leaking at the bearing spraying water on the belts making them squeel.

As the water pump is behind the Timing belt I purchased a HKS kit with bearings to fit as well.

After getting the call to collect the car I immediately noticed hesitation when cold and no power/overboosting at high rpm. (boost would go up from 7psi to about 12 after the car felt like it bogs down so I don't think it's the ECU limiting fuel due to too high boost at first)

Took the car back and took the front end off again. checked all marks and all seemed fine. still no power.

Since then had the issue with the second fuel pump and replaced that with the new relay mod.

when mucking about with an OBD2 device the check engine light flashed so I checked the code and it came up with 34.

I don't recall this code when I first got the car back from the garage as it was just blinking 55.

 

I'm saving for coils and had some friends mention getting the fuel rails/injectors checked due to the pump problems.

Any ideas why the pumps keep failing if not a wiring issue?

 

Do you think I now have to take this to a specialist? I'm worried as the issues could be so spread out they would need to check everything and it would cost as much as the cars worth...

 

Regarding the question about the fuel pressure return pipes, could you elaborate on this? I don't believe the garage touched anything fuel related however my vac lines need looking at as they seem to have been changed slightly by the previous owner so something could be wrong.

 

Thanks.

Edited by Skaith4224

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • wizlb
      Who has a Infiniti Q60, Q50 (V37)?

      By wizlb · Posted

      I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Kinkstaah
      Starting again

      By Kinkstaah · Posted

      Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
    • GTSBoy
      What brakes on R34 GTT(Europe)

      By GTSBoy · Posted

      I'm not going to recommend an EBC pad. I don't like them. Just about anything else would suit me better. I've been using Intima pads for a while now.
×
×
  • Create New...