Head Gasket, Leaking Fuel Injector, What Could It Be

[WogsRus]

Ok so someone please help wog out, I’m going nuts. So basically this is what has been happening to my car.

"Hey just a small annoyance with my cold start. When starting the car up for the first time on the day the idle goes to like 600,700rpm kinda stumbles then just revs out kind of wakes up and then just warms up normally and yeah everything else is fine i know kind of picky but yeah just abit annoying. For the rest of the day turn the car on when cold warms up normal but if its not driven for more than a day or two then yeah does it again could be the cold but also wondering if it may be related to the tps??"

So basically, lately, it seems like the car in the morning simply does not want to start, it coughs and so forth and carries on for 5 seconds, then fine, smooth as silk idle nothing. Almost like it only runs on 4 cylinders first and then all 6 come into line.

The compression test is ok 150 across all cylinders. Rechecked yesterday still correct. Have not performed a leak down test yet.

So, so far i have done the following.

-New plugs, All good.

-Checked compression, still all 150psi even.

-Checked for vacuum leaks, but vacuum appears to be as per before, still to do more searching. Found a hose loose on the intake side fixed that no difference. Still to follow up on full vacuum tests on the hosing and intercooler.

-AAC valve cleaned, and rechecked, and appears to work correctly. Tested with consults, appears to open and closes when tested through consults.

-Redline fuel injector cleaner, special stuff. New fuel filter, new fuel lines.

ALSO did the following test. I put a fuel pressure gauge in and tested the fuel leakage and so forth. Basically if left alone the fuel pressure eventually bleeds off to 14.5 psi, over the night, which is to spec, I need to find the correct page again to give details. So then I pressurized the system and blocked off supply and return. The reading was 40psi, after and hour still 40 psi, after 2 hours 39 psi, but this was at night 11:30pm to be exact. Then over night the pressure dropped of to 20psi or so. However I was told that the pressure loss is worked out over 30 minutes, so if there is no substantial pressure loss the system is ok. THIS IS TAKEN FORM A MECHANIC THAT WORKS ON FUEL DELIVERY SYSTEMS. CAN SOMONE CONFIRM.

-Checked for blown head gasket by getting a snifter test, came back negative. I have used some water recently, but it’s marginal amounts, maybe 100ml or so. I have no water in the oil, or oil in the water. I did have some frof in the water, but I traced that down to the fact that I had some washing detergent left over in the bucket used to refill the water, and this coursed the water to froff a little. All fine now, no more frof. Another thing I did, was to put some pressure into the radiator, not sure how much, but with a hand pump, so very little. I took the plugs of this morning, turned the fuel pump off, and run the engine with paper towels in the holes, no water visible from the strokes of the engine. I let the engine crank over for a while like that to ensure that there was noting in the cylinders, fuel or water. Put the plugs in, and the car still started like crap. So I don’t think a leaking injector or water in the block is the cause. No visible smoke in tail pipe, no overheating, no sweet smell from the exhaust.

-Put a new ECU temp sensor in, no good

-rechecked timing, and still as per before.

-cleaned air filter

-Fuel pressure and flow correct

-Spark plugs all look even and nicely colored.

-Car was tuned 4 weeks ago, this started 2 weeks after that, after we had some massive heat waves in Tas (not sure if this coursed some pinging or anything, not from memory). Also noticed since then the car has lost some boost in high gears, but this is more likely related to 1 missing stud and leaks in the exhaust manifold. CORRECT?

- Put in some temporary earths and nothing.

-Cleaned all the electronic connectors, put on contact cleaner, and some sand paper, ECU and engine side, still nothing.

-checked cold start, but not sure. Put some air through it, appeared to work ok???? Is there a better test for this other then disassembly?

-Reset the computer, drained all the fuel out of injectors, opened all the air bleed vents, and then restarted it the next morning, and it still did it.

Probably ½ dozen other things, just can’t remember what?

I am going to try some block sealer, to see if maybe there is a small chance there is a head gasket leak somewhere. Tomorrow I am having it tested again.

HOWEVER If i turn off the ecu temp sensor, it is fine, if i disconnect the AFM it is fine.

I have not checked cold start operations in Consults yet.

Also have yet to put in a NEW AFM, old ecu and go from there.

I am at a losssss???????

HELP.

NOW please don’t tell me to take it to a mechanic, have been to 3 here in Tas and no one knows anything about imports so I have no where else to go.

I did have two error codes, 13 and 21, have since traced back and fixed, it as nothing no more issues, will redo error codes tomorrow.

SO CAN IT BE A HEAD GASKET???? Or just issues with electronics. What the hell is it. It use to be fine. No all of a sudden, it’s a dog. Need to see what is going on to fix it ASAP.

SOrry for the long winded post

[WogsRus]

bumpidybump

[dwayne293]

Hey mate,

If your exhaust leak is pretty substantial you will have cold start problems....

My 32 GTS-t does it in the morning too, I just give it a quick rev

Best of luck

Dwayne

[WogsRus]

why would exhaust leaks couse cold start issues???? sorry no idea????

[Efex]

Hi Wogs,

Remove IAC, Clean, Function check and replace.

[WogsRus]

yep did that, all working. The AAC and the IAC valves are clean as a whissle. I am getting another one to test, but it all works with consults.

Edited March 13, 2007 by WogsRus

[RANDY]

I don't know the answer, but I might start a betting ring.

I'll just put my money on either a vacuum leak or stuffed exhaust manifold gasket.

Manifold leak... Rough start when cold, things expand when hot, then runs ok... some boost missing could be the leaking manifold too.

Edited March 13, 2007 by RANDY

[WogsRus]

Yeah well the exhaust manifold is leaking badly, you can smell the exhaust gas in the engine bay. I am replacing it this weekend.

Why would the exhaust manifold couse a rough start? I know it makes a differance in a NA car, but a turbo?

Please explain. And thanks for the replies. I scored a full gasket set for the skyline, all banjo seals and so forht, for $150. YYEEEHHHAAA. I can't belive nissan charge $10 per stud for the studs between the turbo and the manifold. CRAZY. I got alll the studs, high tensile, from Nuts and Bolts, $14. LOL.

[Steve]

what heat range plugs are you using?

[WogsRus]

Heat range 6, copper ones. BKR6EYA. I have tried other, with no sucsess.

[Steve]

you should be running a BCPR, not BKR - the BKR is slightly shorter than BCPR, but it shouldnt make a huge difference

6 should be fine too

if you run coppers, I would suggest BCPR6ES gapped to 0.8mm.

It sounds like maybe your car has not been correctly mapped for cold start? it would be worth getting the tuner to check your injector correction at the colder temps, to make sure that is ok...

[WogsRus]

I don't have a PFC, just a SAFC II. BKR are actually longer in the electrode, they are more exposed in the engine. BUT i have tried the BCPR and no diferance. Yeah 5's were too hot, 7's too cold.

In regards to tunning, thsi problem happend about 2 weeks after the tune, it ran fine till then.

Can somone enlighten me as to how a leaking exhaust manifold would effect cold starts????

[kiwi32]

My r32 had a cold start problem aswell turned out to be the start signal to the ecu.

There is a fuse in the fuse box under the dash that is the start signal mine was blown. I replaced the fuse now it starts well when cold.

[WogsRus]

Hum will check that, but i found out today that my FICD selenoid does not opperate. So i recon this might be a couse for my problems. Correct??????????????/

[DREW32]

why would exhaust leaks couse cold start issues???? sorry no idea????

HEY there wogs ,mine used to run fine to on start ups and after the last probs i had which are fixed now ,anyway now i have same sort of prob car sort of stumbles only slightly on start for lets say 3 sec's and then its fine ,though when i had it checked out at the niisan dealership i was informed that i had a exhaust gasket leak at no.6, only slight though, so maybe just maybe it could be a cause but i really dont know either how this could affect it ,the mechanics around my town too dont want to touch my import either F#@^#@ useless they couldnt even put my intercooler pipes bake on properly let alone tell me what was wrong so i fixed it myself and saved $60 an hour doing it,i will fix my leak soon as and see what happens then ,if you decide to fix yours keep us posted nothing worse than a bug you cant squash

[WogsRus]

Well i am about to replace my manifold gasket this weeekend, it is leaking badly, not sounding like a tractor, just leaking.

BUT i think part of it is the FICD solenoid. According to nissans manuals, its a FIRST IDLE CONTROLL DEVICE, not FAST IDLE CONTROLL DEVICE as always throught.

[WogsRus]

Ok so i got the FICD fixed, it was stuck, and now opens and shuts, BUT, it doesn't do anything. If you turn the aircon on, it doesn't rais the rpm of the engine. I checked the air passage and that is fine, and selenoid opens, but no rpm rise.

Also found that the power stearing does not activate the FICD, form the looks of it the switch has some shit caced on it, so need to check that.

Does anyone know how the FICD is suppose to work correctly???

ALSO, the overfloow bottle came up to a higher level then normal, but that is possibly as i was standing arround in traffick for ages, will see if it goes down over the day as the car cools down.

Either way the car started like crap again this morning.

How does a leaking manifold affect the start, echsut manifold that is, is it becaus eon the overalap it might be drawing air in from the manifold???

HELP.

[tom9999]

Sorry to hijack but i do have the same problem, so can someone tell me where the FICD is and how to fix it

Edited March 18, 2007 by tom9999

[BOOSTD]

I had the same issue, turned out to be a leaky head gasket. I diagnosed by removing all the plugs after It was sitting for a while(hot) and turned it over. A jet of coolant from No.6 told the story.......

[Tangles]

my exhaust manifold was snapped in two when we replaced the gasget and studs (tuned the slide highflow to 190rwkw @ 14psi)

snapped in two LOL

quite a site

check yours for leaks, splits etc