car jerking at 2800 rpm and preventing turbo from start

[gtrjon]

wow this is like the exact same problem as my car limp mode and the hicas light would randomly flash. my problems wasnt consistant tho it was always random and my car always started. i ruled out mafs because i replaced them and had the harnesses resodered. I also changed my plugs and tested each coil pack. so im at a loss for you as well... hopefully someone has a solution.

[ozalkl]

update:

I just gave it a try to start the engine as the weather outside currently its -5, I plug in my new Battery in and i turn the key and i saw the HICAS light is on, Tried to crank it, it turns but dose not start, more like trying to start but not picking up, gave her couple long turns more like 5-9 sec turns but still didn't start the engine.

What could have gone wrong? I mean when i parked her it was working except that the car was in a Limb mode and i think it was because the MAF socket was not connected by my mechanic when he did the belt and water pump.

How to troubleshoot?

[ozalkl]

another UPDATE:

I did ECU Diagnose to see what error code it will come with, I followed the instructions etc and it came up with 5 long and 5 short, meaning code 55 which is no error, i tried to give her another start, same thing happen, she cranks but not start, i can see the rpm needle wants to go up to almost 800 but she is not starting.

I need some help from the skyline Guru out there, what could be the problem she is not starting?

[TheyKilledKenny]

It sounds like spark or fuel. Check your fuses especially 6th from the right (fuel pump 15A) top row. Buy a spark tester, and do a spark test. If you have a aftermarket fuel pressure regulator make sure its set correctly. Turn your car to the "on" position and jump in the back seat listen to see if your pump is priming. All else fails bring your ride to a better mechanic than the first.

[nelsonmxmarc]

Sounds like the MAF to me.. Or possibly the ignitor.

If you've been having a shuddering effect, it will cross the band regardless of what RPM you're at if it's coilpack related. Another issue with coilpacks is that they become heat soaked and their resistance drops, causing them to mimic a misfire but only on heatsoaked days/runs.

MAF issue is common and is exactly what you're stating.

Due to cold temps and a sitting car, it's possible you've had condensation in your tank/lines and the water vapour is making your car difficult to start. If the water is severe enough, it could be blocking the lines entirely.

The fuel pump should sound when you click it into ignition. If not, check the fuses.

Other options are CAS.. Ignitor like i stated earlier (which could have been causing misfires from the get go, but usually effected primarily by heat saturation) and MAF.

Otherwise, you're left with fuel - and from what i can read, seems like water vapour in the lines..

Edit; Hicas light is a bit of a finicky situation. It comes on with low pwr steering or power steering related issues, but oddly enough seems to come on when the ignition harness is subject to movement.

Later in the year, my car, running an FET turbo timer, started having hicas issues (deleted of course). The light would come on intermittently until i took the turbo timer out of the harness. It seemed like a bad ground was causing it to come on.

Perhaps check your grounds? Maybe a small rust situation? I think the ground for that harness is directly under the driver footwell cover on the right.

[ozalkl]

will check the fuses and also do a spark test, i suspect the fuel pump, because i dont really hear anything when i set the key to ON since i parked her, Must be always able to hear the fuel pump prime usually?

[nelsonmxmarc]

100% of the time. Even the stock GTS pump, being that it's quiet, will ALWAYS have a faint hum to it. Best bet is to get someone to sit next to the open fuel cap and listen. IF there's no noise, you know it's your fuel pump / fuel pump fuse..

Other options are bad ground (White earth wire to ecu), bad fuel pump voltage regulator (in trunk)

[ozalkl]

alright, will do a test today and see if its the fuse, also will have a friend to check if he hears anything from the fuel pump. I need to get her started

[nelsonmxmarc]

Not a worry, i'm sure we'll get it sorted

[Skym]

I agree.

Should hear fuel pump prime. The fuelpump fuse should be from memory in I think is engine bay? fuse box.

Another way to check fuelpump is check fuel pressure via fuel pressure gauge between fuel filter, fuelrail, as it should be 7.1psi or so above 35.5psi (what it is at idle with FPR vacuum hose connected) before engine is started (no vacuum to FPR). Without vacuum hose connected, it should rise 7.1psi at idle (same as when engine is off).

[ozalkl]

I just went to check and if can hear the fuel pump prime, i connected my battery and i sat in and turn the key to ON, i didnt hear anything from the fuel pump, will check the fuse for the fuel pump and i will also try to open the fuel pump and check to see if the fuel pump sockets having an issue.

BTW, where is the fuel pump fuse? is it in the engine bay or?

[ozalkl]

I just check the fuse for the FP and its good, i had it replaced just to make sure, but i couldn't hear the FP prime, maybe cos im parked on the driveway and its kinda windy today, i will ask my friend to stand by the trunk opened and listen carefully to the FP n see it primes or no.

[ozalkl]

the fuel pump priming, but the car still not starting, i am just wondering, is it possible the timing CAS is not configured properly? i mean when we did the timing belt etc we didnt set the CAS at the proper angle? will this cause the car not to start up? even if it started when we just did the timing belt?

I need some expert info on this? and how do i check if the timing is correct?

[Skym]

Timing light.

After engine has warmed up, connect timing light to battery, loop of black wire that pops out of coilpack loom on drive side of ignition module on top of back of engine.

Undo the 3x mounting nuts on CAS so you can turn CAS clockwise or anti clockwise. Be aware that CAS housing can catch on the plastic that's sits behind CAS housing and not turn fully (makes it annoying to set correctly).

Then aim timing light at crank pully. Should see a red? or orange? looking mark (0 degrees), white marks that are 5 degrees apart and white mark on lower cambelt / timing belt cover. Also timing light should tell you the amount of degrees. Be aware the ignition timing can fluctuate + or -5 degrees and that's the idle stabilisation tables on stock ECU doing that. It can make it a bit difficult to set correctly.

Another way people do it is put a HT lead between coilpack, spark plug and time it off spark plug lead to workaround the idle stabilisation tables.

How to do this is shown in this ECU manual from Link for RB engine (page 10) -

http://www.linkecu.com/support/documentation/g1-engine-management-documentation/gtslinkinstructionmanual

RB20DET should be set at 15 degrees BTDC (Before Top Dead Centre) at 650rpm if it's manual. Auto is 20 degrees BTDC at 650rpm.

Once set, turn engine off and tighten the nuts. If tighten incorrectly (not even between bolts), can get a grinding noise, so be aware of this.

[ozalkl]

is there way to do this and check n see if the timing is off degree without starting the car? as cranks but wont start, this is why im suspecting the off in timing is not getting the car to start.