Cylinder #1 Dropping Completely

[fatz]

Happened to me once

Overheated rb and the block was not true, has a headgasket leak they came and went depending on temp

[XKLABA]

I tried this - water didn't really bubble. A tiny amount of white froth developed as the coolant started to get hot. Not sure if that's meant to happen but I read up that it froths a little when the radiator starts to build up pressure.

Massive head f**k it has become!

that sound about right and my best guess is HG, just enough to upset the cylinder pressures

[Blackkers]

I have a feeling it's the injector. Are you sure they're brand new? I bought the fiveo 1000cc injectors and they are 2nd hand high flows and one even had surface rust. I wouldn't recommend the high flows really. It can be difficult to cold start my engine now.

[SkudR33]

that sound about right and my best guess is HG, just enough to upset the cylinder pressures

I might buy a block tester to check your theory! Thanks for your advice...

I have a feeling it's the injector. Are you sure they're brand new? I bought the fiveo 1000cc injectors and they are 2nd hand high flows and one even had surface rust. I wouldn't recommend the high flows really. It can be difficult to cold start my engine now.

Yeh they were brand new. Even looked new - I knew they were shit injectors but needed something temporarily. You guys think it's a good idea to remove the first injector and then plug it in and crank car over to physically make sure petrol is getting squirted out of the injector? A bit of a big job to swap 1st and 2nd injectors as they are side feed and I'd have to remove the plenum.

[..::R33GTS-T::..]

I might buy a block tester to check your theory! Thanks for your advice...

Yeh they were brand new. Even looked new - I knew they were shit injectors but needed something temporarily. You guys think it's a good idea to remove the first injector and then plug it in and crank car over to physically make sure petrol is getting squirted out of the injector? A bit of a big job to swap 1st and 2nd injectors as they are side feed and I'd have to remove the plenum.

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, plugs, did a compression test, exc.. it was a little water in the dizzy cap... got nothing to do with rb`s but it was just a simple problem...

Edited January 27, 2014 by ..::R33GTS-T::..

[Ben C34]

I might buy a block tester to check your theory! Thanks for your advice...Yeh they were brand new. Even looked new - I knew they were shit injectors but needed something temporarily. You guys think it's a good idea to remove the first injector and then plug it in and crank car over to physically make sure petrol is getting squirted out of the injector? A bit of a big job to swap 1st and 2nd injectors as they are side feed and I'd have to remove the plenum.

Won't there be a huge hole in the rail if you pull one injector out?

[boostn0199]

I might buy a block tester to check your theory! Thanks for your advice...

Yeh they were brand new. Even looked new - I knew they were shit injectors but needed something temporarily. You guys think it's a good idea to remove the first injector and then plug it in and crank car over to physically make sure petrol is getting squirted out of the injector? A bit of a big job to swap 1st and 2nd injectors as they are side feed and I'd have to remove the plenum.

You can change injectors without taking plenum off just need to take T/b off. I would say swap them small job for ruling something out.

[SkudR33]

Won't there be a huge hole in the rail if you pull one injector out?

Hahahaha... I obviously didn't think that through!

I might try removing the TB and swapping the injectors around. I'll keep you guys filled in - thanks for the help!

[XKLABA]

Swap injectors first even if it's just to eliminate them, that is much easier then doing the HG

[nicksamaniac]

If you want to rule out the headgasket, there is a chemical test you use on the radiator to see if combustion chemicals (namely hydrocarbons) are entering the cooling system.

I've used this on a diesel patrol and it's a good way to easily test instead of removing the head if it is ok.

I got mine from Nissan (test kit). But i Borrowed the tool that screws onto the filler neck for the kit to fit into.

bit like a pressure test tool.

[GTSBoy]

If you want to rule out the headgasket, there is a chemical test you use on the radiator to see if combustion chemicals (namely hydrocarbons) are entering the cooling system.

I've used this on a diesel patrol and it's a good way to easily test instead of removing the head if it is ok.

I got mine from Nissan (test kit). But i Borrowed the tool that screws onto the filler neck for the kit to fit into.

bit like a pressure test tool.

These kits are actually looking for dissolved CO2, not hydrocarbons.

[nicksamaniac]

Co2 being a product of a hydrocarbon mixed with o2 to produce it, so yes you are right!

[SkudR33]

Just getting hammered at work - I'll keep you guys filled in on the progress I make!

[SkudR33]

Update and questions...

Ecu is not my problem - tried a working ecu and it still dropped the cylinder.

Tested coolant for exhaust fumes... The test came back negative for exhaust fumes.

Tested injector driver voltages... Injectors 2-6 have a voltage (on the driver wire) of 14.3-14.7, however injector 1 (which relates to the dropping cylinder) had a voltage of 12.8-13.7.

I have no idea how voltage relates to injector timing and tried to search but found the information was way too technical for me! Does anybody know if this could be causing the cylinder to misfire???

Thanks for the help guys!

[GTSBoy]

Low voltage will increase the latency and reduce the total opening, leading to slightly less fuel in total, but it shouldn't miss that badly. But low voltage static might indicate a bad joint or something that will drop the voltage further when it's under load (ie when the injector coil is earthed and operating).

[scotty nm35]

Injector voltage is critical to their operation so I would be looking further into that. Perhaps the ground side is earthing slightly, which may cause the injector to leak.

[SkudR33]

Injector voltage is critical to their operation so I would be looking further into that. Perhaps the ground side is earthing slightly, which may cause the injector to leak.

I managed to get lucky in the sense that for about 1 minute the car stop misfiring and it gave me time to check that voltage... I've discovered that when the car stopped misfiring the injector voltage went back up to around 14.3-14.7.

It seems as though I've located where the problem is... Now it's a matter of trying to solve it.

I'll keep you guys updated. Cheers

[SkudR33]

I've found my issue - faulty injector. If I give it a few love taps, the voltage rises up to normal and it works fine.

Anyone care to explain why that would be happening (for educational purposes) and is there any home fixes or do I have to replace it?

[GTSBoy]

Replace. It will have a short in the coil or something similar.

[SkudR33]

Yeh I definitely will - don't ever wanna go through the headache again!

Thanks to anybody who contributed to the thread...

For future purposes and research, voltages on the injectors should be checked as it turns out a drop of 0.3 volts can cause a whole cylinder to drop!