Jump to content
SAU Community

RB20DET Down 1 Cylinder - Why?

MM2death

By MM2death,
in General Maintenance

 Share

Recommended Posts

MM2death Grand Master

MM2death

Posted
Posted

My brother has just done his timing belt. It was done the correct way by aligning number 1 cylinder to TDC. The CAS is in the same position as before. Checked timing and it was in the correct range.

Now when the car's started, it's only running on 5 cylinders. Number 1 cylinder is down (figured out by pulling the connector on #1 coilpack while it was running).

So the sparkplug was checked and it's making spark. #1 coilpack was swapped with another one and yet #1 cylinder still doesn't fire.

The car was running fine before the timing belt change. It has aftermarket turbo and powerfc.

What else could the problem be and how could i go about diagnosing it?

Any help appreciated.

Scott

Link to comment
https://www.sau.com.au/forums/topic/50728-rb20det-down-1-cylinder-why/
Share on other sites
Revhead Grand Master

Revhead

Posted
Posted

An engine needs three things to run - air, fuel and spark. You've ruled out spark, and we can safely assume it's getting air unless you have a sock or something jammed into the intake runners :P So I'd assume it's a fuel issue. Check that the injector is firing, perhaps swap #1 with one of the others and see if the problem follows the injector, or whether it's in the wiring or ECU (unlikely) somewhere.

If it were a cam timing problem I expect the problem would be consistent across all six cylinders, or at least move between them erratically. The same goes for CAS, TPS and just about any of the other sensors.

Cubes Grand Master

Cubes

Posted
Posted

When I did mine I pulled everything off and lined all the marks up (crank, cam gears)

Pulled the belt off and slipped the new one on (was a nissan one so it had the markings on the belt) I also discovered it was one tooth out on the crank.)

Easy peazy japanezy.

On the dyno it lost a tinny bit of top end but picked up some much needed bottom end.

So your definately getting spark to cyl 1 then?

Stuffed ignition module or wiring to cyl 1?

MM2death Grand Master

MM2death

Posted
  • Author
Posted

Thanks Marc & Joel. All comments taken on board.

Marc, the last time it was running (before timing belt), there were no problems. So i'd have to think that the injectors are fine. FYI, they are 550cc RX7 ones and have been tested and only been in the car about a month.

Joel, i was maybe thinking the ignitor module myself. As you know, you have to take the module off to get to the coilpacks, so in doing this the associated wiring to the module was moved around as well. I notice that the wiring is a bit stiff...prolly from years of heat. I'll pass this info on to him.

Regards,

Scott

blind_elk Grand Master

blind_elk

Posted
Posted

Did you test for spark using the plug in #1? Or did you use a spare plug? Try moving #1 plug to a different cyl and see if the problem follows it. Also, do a compression test (you might have done something nasty like bend a valve while re-aligning the cams and crank).

4door_Sleeper Veteran

4door_Sleeper

Posted
Posted

Did you get wet and a dry compression test results?

This may help determine if the problem is in the top or bottom end.

Whilst I have never looked at the rings on a skyline, I have seen other cars suddenly develop huge drops in compression when the rings turn on the piston and all of the ring gaps line up (nearly all pressure blows past the rings) but this can come good again as the rings move back around.

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

    • PranK
      Chris' Toyota Mark ii JZX110

      By PranK · Posted

      This looks great! Awesome to have the 5 speed with an LSD in this. The Recaro's look like SR2's or SR3's. It's a shame they've been retrimmed as they would have looked sweet in their original colours. I think I'd want my agent to be a little more up front and informative too. I've never imported but I reckon it would make me a little nervous, so the more info the better.
    • soviet_merlin
      Duncan's V37.......race car?

      By soviet_merlin · Posted

      Thanks for doing that Duncan! Makes you a good person in my books. We don't get kangaroos or wombats here. But we have bats and it's similar. AFAIK it's often the mums with a baby attached that get hit because they drop lower when starting from a tree. If you hit an animal, check on it. https://www.ifaw.org/au/resources/wildlife-rescue-app An app to get the closest wildlife rescue contact.
    • Murray_Calavera
      Jacks that fit under GTR lips that can reach the subframe?

      By Murray_Calavera · Posted

      My dream is also to have a proper hoist, but I don't think it will ever happen. My quickjack is probably as close as I'll ever get, it really is very good though. 
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Yeah we keep on in the dailies, it is pretty poor how many animals get hit and the driver leaves without checking....have saved a couple of little ones over the years. Bit of a gruesome job though, pouches generally need to be cut open because they are so tight and often the joey doesn't realise mum is gone so they are still locked onto the teat. I checked the modules in front of the DS wheel where an oil cooler should go.... There is the radar unit - that can go for race use) One of the 2 HX water pumps, the silver cylinder. That needs to be kept but might be able to be relocated But the bad news, the big computer mounted vertically in front of the wheel (blocking any potential air exit) is the electric steering computer. That is required until/unless i do a hydraulic steering conversion, and in CAD based modern car design it is not like I can just pop a big unit like that somewhere else (plus the loom would be too short anywhere else too). So, the passenger side is OK to clear out (just use a smaller washer reservoir, potentially elsewhere), but the DS no beuno
    • Duncan
      Chris' Toyota Mark ii JZX110

      By Duncan · Posted

      Well, all the best with the new camry It was interesting to hear about the UK process, it is generally a lot more streamlined here with a shipping agent looking after all the import side (noting the exact final price can still be a surprise.....) and I've used a few different brokers on the japan (or US) side, and never had any trouble with any of them....luck of the draw I guess. You mentioned you didn't get the auction sheet (understandable since you bought it from a dealer, not auction), but I always try and get hold of that because they are pretty thorough. I've imported 2x R grade vehicles over the years and both were fine, repairs in Japan are pretty thorough compared to here in Oz.
×
×
  • Create New...