Something wrong when car starts in the morning!

[Kentoxboy]

Question #1)
Almost couples times a week when my 2000 rodeo 3.2L v6 (109,000 miles) starts in the morning, the rpm goes over just a little bit over 1000 rpm (which is normal) then suddenly it will drop lower and lower until it reaches to 0 rpm and in the mean time the engine starts shaking (sounds like it tries to kick itself back it but couldn't and sounds like knocking?) then the engine shuts off. After 5 sec. when I start the car again, it starts PERFECT! (It is always the first try that it happens) I check oil, tranny oil, clean the "butterfly" and it still happens...
It only happens in the morning/first time starts... No codes or anything (its been like this for more than 1 year now)
Please help me fix this problem...
Question #2)
On http://www.isuzufaq.com/ for question #15 the website recommand me to use Denso K16PR-P11 spark plugs and the link is http://www.sparkplugs.com/results_app.asp?AAIA=1363272&mfid=3
when you click on it, it shows Double platinum PK16PR11 but not Single platinum K16PR-P11. So which one fits my 2000 rodeo v6 better?

Thanks!!

[amigo-2k]

Sounds like you have a classic intake manifold gasket problem (I have had to replace mine 2x under warranty). If you are the original owner you are covered too.

As for plugs I ordered the double platinum ones and have had no issues (25k on them now).

[aznstormin]

Originally Posted by amigo-2k

As for plugs I ordered the double platinum ones and have had no issues (25k on them now).

Which engine do you have? A 2.2L (X22SE) 4 cyl or 3.2L V6(6VD1)?

[amigo-2k]

3.2l

[johnsm]

2000 Rodeo V6

I have the exact problem. I did two things. 1) I cleaned out the pvc valve. It had alot of junk in it. Make sure you clean it with carb cleaner and then blow through both ends. you should only be able to blow air through one side. If you can blow through both ends, replace it with a new one.

2) I took a look at the fuel pressure regulator and noticed that one of what I assume is a vacuum hose was still connected, but its clip-on support had detached, and was flopping around. I secured it.

I have had 3 successively better morning starts since.

I think this is a vacuum problem. The pvc valve may have been malfuntioning due to a dirt problem or a vacuum hose was loose then the initial (failed)morning start would suck the hose in to make an airtight seal. Then upon restart the car would operate properly for the rest of the day.

The mystery is why after the initial restart the car could sit for 8 hrs in the daytime and restart without a hitch. Although if it sits overnight it has an idling problem only on the first startup. Temperature, moisture who knows.


John

[Kentoxboy]

Originally Posted by johnsm

2000 Rodeo V6

I have the exact problem. I did two things. 1) I cleaned out the pvc valve. It had alot of junk in it. Make sure you clean it with carb cleaner and then blow through both ends. you should only be able to blow air through one side. If you can blow through both ends, replace it with a new one.

2) I took a look at the fuel pressure regulator and noticed that one of what I assume is a vacuum hose was still connected, but its clip-on support had detached, and was flopping around. I secured it.

I have had 3 successively better morning starts since.

I think this is a vacuum problem. The pvc valve may have been malfuntioning due to a dirt problem or a vacuum hose was loose then the initial (failed)morning start would suck the hose in to make an airtight seal. Then upon restart the car would operate properly for the rest of the day.

The mystery is why after the initial restart the car could sit for 8 hrs in the daytime and restart without a hitch. Although if it sits overnight it has an idling problem only on the first startup. Temperature, moisture who knows.


John

To Ryan,
How can replacing the intake manifold gasket will help slove the problem? and Why did you need to replace it twice? and if so, I am the 2nd owner, so how can I replace it myself like DIY?

Thanks

To John,
I replace the pcv valve last week and maybe alittle bit better? but it still have the same problem... (a little bit chocking sound when i start in the morning but when I step on gas [while the car is Park], my rpm goes back up and I can avoid the rpm drops to 0)
Where is the vacuum hose and how can I clean it?
and after all you clean and changed the PCV, do you still have the same problem?

You are right about the mystery, it always happen in the first morning try... Later the day it never happens! mmmm...

Thanks.

[snowskateskim21]

I would run a fuel filter service on it at a Jiffy Lube and/or a fuel system cleaning. I work at Jiffy Lube and when they do this service they clean out the vacuum line and works great. If you don't want to bring it to a shop, go to a auto store and buy fuel system cleaner that you dump into the gas tank.

[Kentoxboy]

Originally Posted by snowskateskim21

I would run a fuel filter service on it at a Jiffy Lube and/or a fuel system cleaning. I work at Jiffy Lube and when they do this service they clean out the vacuum line and works great. If you don't want to bring it to a shop, go to a auto store and buy fuel system cleaner that you dump into the gas tank.

I do buy those fuel system cleaner and use it every 2K-3K miles.

[johnsm]

I don't think it is the intake manifold gasket because you would get random surging rpms and ocassional sputtering rpms while driving around town.

I have had about 6 good starts since I worked on the Rodeo. Now I have had a couple of morning starts with a slightly noticeable sputter.

Since you changed your pvc valve and you got better but not perfect performance, you should maybe identify all your vaccuum hoses and wiggle there connections to ensure they are secure and not leaky.

The fuel pressure regulator may be internally leaking and have to be replaced. It is located at the drivers side firewall attached to the fuel rail. Check the two small hoses that it is connected to for looseness and leaking. Your pvc valve hose is a vacuum hose check if that is not damaged or dirty. It would be great if everyone could help and identify any other vacuum hoses.

There have been other posts with the same problem and there fix was the replacement of the fuel pressure regulator.

John

[weathermedic]

Had the same problem with my 01 Rodeo V6 for almost a year. Most mornings or after parked for about 8 hours, it would do the same thing. Once it started. I could shut it off and it would start right up with no problem.
Problem seemed to go away after the dealer installed new engine wiring harness and the intake manifold gasket, which you have to replace when putting in the new engine wiring harness. No sense in putting back the old gasket. I had the original gasket replaced under warranty about 40k miles ago.

Jason in NYC

[Dober89]

The intake manifold gasket can cause the engine to run rough because its leaking and pulling in air that isnt accounted for. When mine went the car would always stall when I put it in park and sometimes when I started it up also. To check for a leak, take off the plastic engine cover and spray some carb cleaner around the lower gasket near the cylinder heads. If the engine sputters when you spray a certain spot then the gasket is leaking and you should have it replaced.

I just replaced mine for the second time at 85k miles. They are made from a very brittle plastic and they dont hold up all that well. The first time it was replaced it had about 55k miles on it.