For about a month ive been having a hard start. I checked the code and it was an IACV code. It wasnt that serious at the time it was intermittent. It would take about 15 seconds to start. around a week and half ago the problem became worse, my idle would jump up and down, i had really bad gas mileage like 15 mpg recently it jumped down to about 10 mpgs and i had a really bad gas smell. I Replaced the iacv and it ran perfect for about two hours no gas smell no more rough idle. I get off work and its worse than ever now theres smoke coming out the tailpipe. I checked the codes again and i had both bank one 02 sensors and cylinder 5 misfire. i cleared them out and this morning i have a 1320 i swapped all the rear bank coils out with an extra set i have. I started troubleshooting by unplugging the coil connectors and the two rear right cylinders are not responding when i unplug them. Im stuck now can anybody give me some advice on the next possible cause. i Believe its a vacuum leak because i see smoke coming out the rear of the engine but at the same time i dont remember any hoses back there except for a coolant line. And again can somebody steer me in the right direction because i dont feel like taking the manifold off for no reason.

 

What you may have is 2 fuel injectors stuck open or the o-rings for the injectors cracked and leaking. The 2 cylinders that don't change are no doubt the ones with the problem.

A vacuum leak would cause a bad idle, but it wouldn't cause smoke to come out the tail pipe.

 

I agree with Dennis.

I once had a problem with two injectors causing random misfires and uncontrollable flooding. I could smell gas from the flooding. The injectors had broken pintle caps as shown in the picture. I swapped coils and changed spark plugs to try to fix the misfire problem without success. I finally pulled the injectors from the rails and found broken pintle caps. To correct the problem I ordered a kit from eBay for $34 as shown in the 2nd picture and carefully refurbished my injectors.

 

yea i agree i think the cylinder number 5 has a bad injector. I did a smoke test earlier and found a hose was leaking and that helped it a little. Its weird though because after fixing the hose the car was doing a lot better the idle was almost back to normal there was alot less smoke but as the car warmed up the idle got worse and the smoke came back really heavy. is there any other way to test this injector? Good thing is that i have a whole extra set of injectors lol

 

There are testers for injectors but they are pricey so the average person doesn't buy them. The tester energizes the injector coil for some amount of time and then shoots a liquid through the injector into a calibrated container. The amount of liquid is then measured for the correct amount.

About all you can do is measure the ohms of the solenoid to see if it is correct and inspect the pintle caps.

 

Well the pintle cap was busted on it and the o ring separated from the injector I replaced it with one of the used spares , after getting everything back together it started a lot better there was still a lot of smoke, after about 20 seconds of idling the smoke cleared up and ran good for a few more seconds them the smoke came back even worse and it stalled , it was hard to get it back started and it only ran for a few seconds and stalled again , I'm thinking fuel pressure regulator what about you guys?

 

Is it white smoke or black smoke. Does the smoke smell like un-burned fuel, burning oil, or antifreeze?

Some general symptoms of a bad Fuel Pressure Regulator (FPR) are:

Lack of fuel pressure, excessive fuel pressure, black smoke and rich engine running condition, instant drop of fuel pressure once the vehicle has been turned off, and delay building sufficient fuel pressure.

 

You stated that you have 2 cylinders that don't change anything when you disconnected the coil. You changed the fuel injector on just one of the cylinders. Maybe it is the other cylinder.

CS_AR asked some questions about the color of the smoke and that would be helpful to have the answers.

CS_AR also gave you some pointers about FPR symptoms. I'd like to put an asterisk on the one symptom, "instant drop of fuel pressure once the vehicle has been turned off". If you have a leaking fuel injector/bad o-ring, this would also cause fuel pressure dropoff.

 

it ended up being that #5 injector after reassembling everything i had accidentally switched a coolant hose with vacuum hose,that caused stalling and even more white smoke after double checking the hose i corrected the problem and instantly the the idle was back to normal and after about 45 minutes of driving all the smoke cleared out and its been fine ever since. thanks alot guys