Starting Issue

[MrStabby]

When i try to start the GTR it turns over fine, but coughs to life, and then runs rough and rpm keeps falling until it stalls - which takes about 10 seconds. Throttle doesn't help to raise the revs. What should i check first? I was thinking maybe fuel pump, but its only about 3 years old (sard) so I hope it hasn't died already.

Any ideas?

[Hadouken]

Vacuum leak. Spark plugs.

[MrStabby]

Update: no sensor warnings via consult

The car was running fine before I parked it, then dead when i came to start it again, so I think spark plugs are unlikely. I'll try to find a vac leak. Needle in a haystack..... cant use the aerostart trick because it doesnt run long enough.

[SargeRX8]

Spark plugs unlikely? Sounds EXACTLY like my car after spark plugs were fitted in about a week earlier. Fresh plugs went in. Drove home from work at night. Parked the car. Next day tried to start it up the car coughed and spluttered, started and died then would never fire up. New plugs, started up just fine. Plugs got fouled.

If you've failed to start the car a couple times, every time after that you are wetting your plugs and pretty much f**king them up. Try new plugs, if it doesn't fire up, then try the fuel pump test. Remove the hose from the fuel pump to the rail, put it into a bucket and check its flow for a couple of seconds. If its moving fuel, and you say throttle doesn't help it start, I'm going to say spark related.

I don't know how you would develop a vacuum leak after parking the car but if you did have one, the car will start and just idle rough with alot of black smoke. Ive had minor and major leaks and each time the car does start, its just rough as ass.

[NoFigJamHere]

Mate you didn't put petrol in it just prior to the problem? I had a similar thing about 4yrs ago n it ended up that the fuel i put in the night before from a servo that "apparently" didn't sell much v'power (shell servo obviously) let their under ground tanks run so low i got so much rust with my v'power i needed to replace all injectors, fuel filter, fuel pump, remove the Farking tank to flush it, only reason i didnt burn the servo to the ground is the owner paid me $1950 for repairs...he insisted i provided legit tax invoice and information of the w'shop that did the repairs so he could call and verify. Which was easy coz i had a workshop hope yours aint same issue hey... I'd suggest you pull plugs out just to determine if its getting fuel, and if theyre fouled up you more than likely have a vacuum leak sumwere thats causing it to have the excess fuel pressure. Does billow black smoke or smell fuely when it does inda run?

[NoFigJamHere]

*kinda run

[MrStabby]

Well i had put in a tank of United 100 as my car seemed to like their 98 a bit more than other 98s, and the station i went to didnt sell the 98 anymore. I haven't smelt fuel. I guess its worth checking how the plugs look as that's pretty easy and will let me know if they're wet with fuel or not. They're iridiums so should be more resistant to fouling than coppers.

The service manual points to fuel pump, so i'll see if supercrap have a pressure tester and get a new filter while i'm at it.

Thanks guys - keep the ideas coming.

[MrStabby]

Ok plugs are clean and in good condition

[levinboy]

Could be your fuel pump is on the way out if it's the std pump.

Could also be a bad batch of fuel, throw in some octane booster and see if it helps

Are the spark plugs at the right gap??

[MrStabby]

Swapped fuel filter and pump - its not even coughing now. Tried to start with vac signal disconnected to regulator, also no good.

Could a dying ignitor cause this?

[SargeRX8]

Check if your plugs are getting wet, are the injectors pulsing? Remove a spark plug and touch it to the head, can you see a spark arc? Need to know if you are lacking fuel or spark. My money is still on plugs. fould plugs.won't look any different to working plugs. You were getting coughing and now it's just turning over without any coughing. Would indicate either no fuel flow at all (unlikely), or no spark.

[BOOZTJUNKEY]

Can u swap the cas with a goo one to be safe. ?

Or even the igniter module ?

[Nanogrip]

I think you can idle without the air flow meter, but check it in case. Also could be a leak in some of the positive pressure air lines, or boost gauge lining?