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My New Motor Is Missing!

OMGGTR

By OMGGTR,
in Engines & Forced Induction

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OMGGTR Mentor

OMGGTR

Posted
Posted

Hi guys,

I just built myself my first rb26 its imac so dont question the build quality.. ty

R33 GTR s3.

Problem i have must be an ancillary, the problem is cylinders 3 and 4 are dead.

Tested the following at a mechanic who works on them all the time (wont name him)

- ignition system

- spark 100% the cylinders are firing electronically

-Ignitor

-coil harness

-ecu swapped with 3 others( running std ecu and fuel system )

-cas checked swapped over with 3 others

- fuel system

-injectors from 1 and 2 which are working swaped into 3 and 4 no change

-little noid lights tested electronic pulse all ok they are working

-flow chek has pressure

-Head

-i asked him to chek my clearances encase a valve was too tight he says they are spot on ( didnt give me a measurement tho).

-Block

- Comp tested to 160 psi on all cylinders engine has not been run in yet so will increase.

Im running out of ideas..... please help have i missed something?

I have a new fuel pump id1000s tomei type L reg and tomei rail ready to go on... should i install it all and see maby the mechanic missed something ? also have a D-jetro which is semi installed (all the intake manifold work already done but blocked temporally untill i install the ecu... the work was done when i had the intake off...

Any info would be great maby a shit mechanic ? maby he missed something ? what to do ... im planning on pikin up the car and going over shit myself the reason i gave it to him was i have no time ....

cheers.

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blk94r33 Mentor

blk94r33

Posted
Posted

So you have spark, fuel pressure, injection pulse, working injectors and good compression, but still have a miss? If all the above has been eliminated %100 there's little left to cause it.

-How are you checking spark? (As in with a proper spark tester or other method)

-What are the plugs like? Could they have been fouled badly enough during the first start up to cause the miss? Cracked or damaged during fitment? Is there signs of coolant or contamination (ie leaking headgasket)

-Is the intake or exhaust restricted somehow? (Unlikely as it should have shown up on the compression test) Ie. are 2 of the ITB's if you're still using them bent or damaged? Is something jammed in the intake such as a rag or tape left over from the assembly?

-Is fuel getting to no. 3&4 injectors from the rail?

Also:

-When does the miss occur? Idle, light throttle, light/medium load, free revving, constant?

-Is it a dead miss as in the car barely runs, or are 2 cylinders not contributing equally?

blk94r33 Mentor

blk94r33

Posted
Posted (edited)

Is there anything different about cylinders 3&4 to the others? Ie a vacuum line or two running off them that the others don't have?

More information on the engine would help too.

Edited by blk94r33
OMGGTR Mentor

OMGGTR

Posted
  • Author
Posted

ok to answer everything

the miss is complete the cylinders are dead if u pull a coil pack lead off no difference is noticed... on either cylinder

spark was tested by removing my plug putting another one in flipping the coilpack with the plug in it still using a jumper cable to earth it and run the motor the spark is decent no abnormality

plugs are ok not fouled or anything....

no sign of coolant fouling them

The only difference these 2 cylinders have is the 4mm nipples for the d-jetro map sensors which have been blanked off and checked 2 times if they were leaking to cause the issue ....they were loctited in also. so no chance of leak

im still thinking fuel is a issue i cant prove the fuel is actually exiting the injector.... but the mechanic said he swaped over 1 and 2 to 3 and 4 no difference... unless he bullshitted to make some doh.... :S

the miss occurs instantly on start up and does not stop. they are dead...no rags or anything stupid in the intake

not sure on engine info but its a 2.6 litre rebuilt with forged everything 270 10.80mm lift pro cams tomei lifters / valve guides type b springs etc the works the head was built by martini heads they did a great job

all machine work was done by duggan balancing.... block was hot washed etc for 2 hours by myself cleaning all oil galleries etc...

arp bolts / studs through.... tomei oil pump ....... i duno what else ummm -5 turbos .... if u need specifics let me know

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

im still thinking fuel is a issue i cant prove the fuel is actually exiting the injector....

That should be pretty easy to work out...

Aside from that, what is controlling the car now while the 270 cams are in it?

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Don't have another lying around to rule it out?

Surprised it even idles actually with a stock ECU.

Pete's Q about the gasket was probably more along the line of is it 100% sealed. Often something overlooked and easy to get wrong when changing, has it been checked that it's totally sealed?

GTScotT Grand Master

GTScotT

Posted
Posted

I had a similar issue which ended up being damaged wiring on the igniter side. Cylinders 3 and 4 kept arking out when under load.

The coils would work fairly normally when id pull one out and test it earthed against the intake etc. Luckily the wiring was physically damaged so wiggling it would make it sputter and i was able to find the breaks.

Without having the car at home and diagnosing these things yourself its really hard to be sure of whats going on.. :(

GTScotT Grand Master

GTScotT

Posted
Posted

If it dropped 2 cylinders under load with a weak battery I would say there is tarnished/perished wiring somewhere in the engine bay.

Make sure youve got good earthing at minimum.

STATUS Grand Master

STATUS

Posted
Posted

Ok got the car back today payed the prick 260 bux for doin nothing got it to my workshop and me and the guy i work with fixed it

Was low voltage battery was f*ked..

surely they checked voltage? i suspect there is more to it? dodgy earth etc?
GTScotT Grand Master

GTScotT

Posted
Posted

If it dropped 2 cylinders under load with a weak battery I would say there is tarnished/perished wiring somewhere in the engine bay.

Make sure youve got good earthing at minimum.

surely they checked voltage? i suspect there is more to it? dodgy earth etc?

Na trent he didnt....

3 strikes, your out.

Time to get your leccy skills on.

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