Jump to content
SAU Community

Cylinder #1 Dropping Completely

SkudR33

By SkudR33,
in Engines & Forced Induction

 Share

Recommended Posts

  • Replies 57
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Popular Posts

GTSBoy
GTSBoy

Injector loom, but not ignitor. Seeing as the ignitor is on a whole other loom for a whole other part of the fuel-go-bang system.

SkudR33
SkudR33

Hey guys, Been trying to troubleshoot this issue which occurred one day while I was driving the car during the stinking 35+ degree hot weather. My 1st cylinder is not firing at all. Some days it s

..::R33GTS-T::..
..::R33GTS-T::..

id defiantly give it a go, worst case after you pull everything out is that It works, then you know the injectors wont be the issue.. my old pulsar was misfiring on 1st cylinder, replaced leads, plug

SkudR33 Proficient

SkudR33

Posted
  • Author
Posted

I started off by pushing the positive probe into the back of the plug in the ecu. Managed to wedge it in so that it touches the terminal. Then earthed the other end on the chassis.

I think it made it easier because the microtech ecu has roomy plugs... The only other way to do it is to strip the wires, but you gotta try do that without destroying them.

Shoujiki Proficient

Shoujiki

Posted
Posted

A good way to probe the back of any terminal or connector is to insert a small pin into the back of the wire terminal first, and then probe that pin with your meter. Helps to get a good solid connection into the wire (for accuracy, especially in this situation, where 0.5v can mean a pass or fail) and also doesn't damage the wiring or terminal from trying to jam a big probe in there.

SkudR33 Proficient

SkudR33

Posted
  • Author
Posted
A good way to probe the back of any terminal or connector is to insert a small pin into the back of the wire terminal first, and then probe that pin with your meter. Helps to get a good solid connection into the wire (for accuracy, especially in this situation, where 0.5v can mean a pass or fail) and also doesn't damage the wiring or terminal from trying to jam a big probe in there.

Yeh - I wish I had read this post before I attempted it myself :P. Luckily the plugs for my ecu have a large enough gap to fit my probes.

  • 1 month later...
lismo Community Regular

lismo

Posted
Posted

Hi all,

First of all i'd like to say sorry about the long story.....

I am now having the exact same issue. Cylinder 1 is not firing at all. Was fine one day and just completely dropped out the next day. I must say though occasionally on start up it would run rough like it was dropping a cylinder but within 30 seconds would pick up and run completely fine.

Im running an apexi pfc ecu.

So far we've eliminated spark plugs, splitfire coils, coil wiring harness and harness plugs. Tested the injector as in, it was wetting the plug but not igniting the fuel. Placed coil slightly away from sparkplug and we could see it sparking the top of the sparkplug but its not igniting inside the cylinder. It has been compression tested and its all good there although cylinder 1 is slightly wet with oil....

My injectors are 570cc sard and are about 5 years old and the splitfire coils are same age.

I dont actually use my skyline very much so it sits in a garage as i use my daily most of the time. So i let the rego lapse for about 2 months and in that time i didnt even start the skyline. Ive never had a problem like this before where it hasnt been an obvious issue.

Once registered and i took it for a drive around for the day it split the radiator bleed valve hose but the car didnt get too hot as i realised something was wrong as soon as it happened, i replaced the hose, filled coolant up and drove away with no issues. I started the car 3 days later and thats when it dropped the first cylinder and we've been just testing and eliminating with no success so far. Thought i'd mention what happened with the car in the lead up to the cylinder not firing.

Next step we were going for was to get a test module (black box at back of engine on top of coil cover)

I was also told to check the crank angle sensor but they are expensive things to buy for testing if thats not the issue.

Thought i'd read the sau threads as ive fixed many issues myself from people posting on this awesome site!

Skud33 does this sound like the exact problem you were having with your skyline?

Like not igniting the fuel in cylinder but sparking from the coil to the top of the sparkplug?

I did read that you checked your injector voltage and that was the problem but how did you check them?

Does it need to be checked through the ecu?

I wont be doing this myself, i will be asking my mechanic to test it for me.

Did you end up just replacing the one injector?

Thankyou so much to anyone taking the time to read my post and respond

: ) liz

  • Like 1
  • 2 weeks later...
  • 1 month later...
Ryno Experienced

Ryno

Posted
Posted

I'm also currently dealing with this problem of #1 cylinder not firing on my RB25.

As I have a wideband permanently wired in, I was quickly able to diagnose that the #1 injector was not squirting fuel. I initially thought the injector was clogged so cleaned it and reinstalled and a week or so later the problem resurfaced. I then figured the injector was on it's way out and ordered a new Nismo 555cc from Japan.

After driving to work on 5 cylinders for the last two weeks, with the car sounding like a poxy WRX, I installed the new injector only to find it is still not firing on that cylinder.

I have found the problem, as I connected a mutimeter to #1 then #2 injector plags and found that #1 is only getting 7.5 volts and #2 is getting 11.5 volts. Any idea what would cause this?

My next step will be to pull the injector loom apart and look for anything dodgy there.

SkudR33 Proficient

SkudR33

Posted
  • Author
Posted

I'm also currently dealing with this problem of #1 cylinder not firing on my RB25.

As I have a wideband permanently wired in, I was quickly able to diagnose that the #1 injector was not squirting fuel. I initially thought the injector was clogged so cleaned it and reinstalled and a week or so later the problem resurfaced. I then figured the injector was on it's way out and ordered a new Nismo 555cc from Japan.

After driving to work on 5 cylinders for the last two weeks, with the car sounding like a poxy WRX, I installed the new injector only to find it is still not firing on that cylinder.

I have found the problem, as I connected a mutimeter to #1 then #2 injector plags and found that #1 is only getting 7.5 volts and #2 is getting 11.5 volts. Any idea what would cause this?

My next step will be to pull the injector loom apart and look for anything dodgy there.

Run your multimeter across the metal pins in the injector where the loom plugs in and check resistance - it should be roughly 12ohms. If you get a resistance of 12 ohms, this will confirm your injector is not faulty... Other thing I'd check is the voltage for that first injector at the ECU. It might be breaking down somewhere along the loom? Or check for continuity in the loom.

If you need anymore help let me know :)

Ryno Experienced

Ryno

Posted
Posted

Cool, I've ordered a new injector loom (from "Wiring Specialties" in the states) so hopefully that fixes the issue.

In the mean time, I'll check for any obvious problems with my old loom (continuity, grime in plug etc). As driving around on 5 is killing me!

Ryno Experienced

Ryno

Posted
Posted

I've fixed the problem, and the solution was so simple I feel rather foolish...

I checked all the plugs and continuity of both the injector loom and from the ECU to the injector plug (for the injector loom). All tested good, however when I unplugged the ECU I noticed the end of the ECU plug wasn't quite flush with the housing on the ECU.

Cylinder #1's ground is right at the end of the plug (pin out 101) and so is a switched 12v power (pinout 109) - which I imagine powers the injectors. When I looked inside the plug I noticed both pinout's 101 and 109 had a slightly splayed female connection. So I closed the connection back up, bolted the ECU plug back together and the problem is fixed.

I guess over time the plug worked it's way loose at that end and #1 cylinder was the first to drop offline when the connection became dodgy.

SkudR33 Proficient

SkudR33

Posted
  • Author
Posted

I've fixed the problem, and the solution was so simple I feel rather foolish...

I checked all the plugs and continuity of both the injector loom and from the ECU to the injector plug (for the injector loom). All tested good, however when I unplugged the ECU I noticed the end of the ECU plug wasn't quite flush with the housing on the ECU.

Cylinder #1's ground is right at the end of the plug (pin out 101) and so is a switched 12v power (pinout 109) - which I imagine powers the injectors. When I looked inside the plug I noticed both pinout's 101 and 109 had a slightly splayed female connection. So I closed the connection back up, bolted the ECU plug back together and the problem is fixed.

I guess over time the plug worked it's way loose at that end and #1 cylinder was the first to drop offline when the connection became dodgy.

Good news :) glad I could help...

  • 1 year later...

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...