car not running smooth

[onlybui]

Yesterday I drove with no problems, park the car come back and now the car won't start, it turns meaning I have fuel and but it won't crank over. I check the the hood and found a air leak, Fixed that by cutting the hose, and now the car starts. I'm driving and notice the car is not running smooth, it looses the rpm when I gas and then eventually dies, thank god I was able to drive it home. Does it sound like I need to change the coil pack because its miss firing? Looking to upgrade the coil pack and get the yellow jacket or is it something totally different. Today I started the car and let it sit and the car is running rough. The car idle below 1
When I bought it last year
I changed the fuel filter
Spark plugs
air filter (need to upgrade and get air intake)
oil.

[amnash]

what do you mean you fixed it by cutting the hose? you just blocked it off?
you can use a multimeter to test your coils, just unplug them and measure bewteen + and - pins resistance between 0.6-0.9 is a pass

have another check for air leaks useing the propane method(youtube it) and repair anything you find.

[DarkCaporaL]

Check your intake piping for boost leaks. Sounds like a pipe came off.

[onlybui]

oh there was a split in the hose I just cut it and re inserted where it came from. I justed youtube the propane tank will try again, SO when the car doesn't run smoothly could it just be a vacum leak problem?

[DarkCaporaL]

If an intake piping came off the car usually wouldn't even start (first issue you described). If it did start then it would only want to die down unless you gave it some gas.

If you're sure you dont have any boost leaks, then you need to find out which cylinder is missfiring. Check your plugs and see what they tell you. Unplug your coils one at a time until you hear no difference in RPMs, this will be the cylinder that is not firing.

What are your actual symptoms at this point? Does the car start? Do the RPMs climb when you press on the gas? etc. The more information you give on the issue the easier it will be to diagnose.

[onlybui]

When I started it today it started< I let it idel and open up the hood to see if I can see anything or find any more leaks anywhere, and by just being under the hood the car would idle but is rough like its about to die and countines to go back and forth, staying under 1 on the RPM gauge. I might drive around the block to see if it dies on me but kinda think the problem is not solve because its not running normal.

[amnash]

[onlybui]

uplugged the battery plug it back on and turn it on... starts and runs normal for a good1-2mins and then rpm sits @ 900-800 back and forth and then almost dies and HICAS light comes on, sounds like I have a vacum leak somewhere gonna try the propane later on today...

[jinglebell17]

oh there was a split in the hose I just cut it and re inserted where it came from. I justed youtube the propane tank will try again, SO when the car doesn't run smoothly could it just be a vacum leak problem?

It could be as simple as that. Keep in mind that it could be a number of things so don't spend the rest of your life looking for that vacuum leak

[AaaronF]

i had a few of the same issues... i would check what your alternator is charging at. If its below 13.6 its bad. it might be missfireing because there isnt enough power to the plugs. I replaced the alternator and it ran fine again. My HICAS light came on as well.

[jinglebell17]

ya my HICAS light is on too lots of the time. Ill go buy one today. I finally get my window regulator I've been waiting for so Im doing that today. And I put the stock downpipe on yesterday so all i have left to do is take my tint off and fix the door hinge pins and my car is safetied

[nelsonmxmarc]

Certainly seems like a vac leak.. Reason is - car runs fine on start up. MAF and O2 is closed loop at this point since it's running on cold start maps. Once the O2 feedback kicks in and there's all this extra air passing by the MAF at an arbitrary point, one is going to register rich, while the other is going to register lean.

If you watch a wideband under this condition, generally you see 17+ :1 AFR - lean condition. Typically runs like doody..

Better than the propane (never had luck with it unless it was an obvious leak), build yourself a boost leak tester with a PVC pipe end, shrader valve fitting and a coupler. Plug that on your intake and pressurize the system. You'll find your leaks in no time.

[mfroese]

[onlybui]

You guys are awesome but anyone from winnipeg wanna get my skyline on the road lol... Ok so today i started it again and same thing cold start and then i have to keep the gas for it not to die and notice that the exhaust is giving a grey heavy smoke, I did that for good 2-3 mins to see if the car just needs to warm up and then took off the gas and dies. Try to start it again and it won't start. So I open up and look at my coils and notice that 1st coil have oil build up around the screws? Anoher problem that could be it?

[nelsonmxmarc]

Pull the plugs out and see.. Possible you're stuttering on 5 cylinders and the oil is a result of excessive blow by. White smoke would be a sign of coolant entering the cylinder, due to cracked head/blown hg/cracked water gallery (pretty rare). You can generally tell by smelling/tasting the moisture as it leaves the exhaust - sweetness is a telltale sign of a coolant leak.

Have you even bothered to check for boost leaks or done any of the tips mentioned above?