VX trouble

[dogue]

I just (less than a week ago) had the fuel regulator and Fuel pump replaced under warranty and yesterday it stalled twice on start up. They are replacing another part. One question I have is about injector cleaning. When I bought my VX used I took it to the dealer to have an oil change and check the vehicle out. They suggested since I purchased the vehicle with 30k miles that I have the injectors cleaned, throttle body cleaned and decarb the engine to the tune of $279. Soon after that another shop suggested the same job on my wifes minivan. I took their suggestions and did both services. I since have been running injector cleaner through the VX every 15k miles and I always use supreme fuel. The next oil change I had a different tech suggest I have the same thing done, when I told him I had just done this 3 months prior he then said Oh OK. Now they are suggesting I do it again, less than a year from the first time. Is this a new scam to get people to drop more than the cost of an oil change. I am only 30 years old, but I have owned many different cars and never had anyone suggest cleaning more than every 30-40k miles and it has always cost about $80 to clean before, now it is more expensive and more frequent.

[Tone]

Injector cleaning / decarbonization at a dealer or fast lube place is a good idea every 20-30K miles but not as often as they are suggesting. Running super unleaded is a waste of money and in most cases has no more additives that the regular. Running over the counter cleaner every month or so is a good idea as well.

Did they replace the fuel filter as well?

[Navigator]

Gasoline is an excellent solvent. Highway driving helps keep your engine clean as well. Stomp the pedal every now and then to flush out the contaminents, and change your fuel filter regularly.

[dogue]

Thank you for the replies. I mainly drive highway miles. I also stomp on it regularly:) I believe the filter was changed during my last regular service, but I will try that this weekend. They ended up replacing the idle air control. If I have any similar problems I am going to take it to another dealer, the tech here seems to give me a look like I am making up the problems and he has yet to answer my request to check for a intake gasket leak. I mentioned that many other owners have had a similar problem with high rev idle because of the gasket leak and he just looks at me blankly. Anyway, I picked it up just an hour ago and so far so good, I will have a better idea when I start it cold tomorrow.

[Tone]

Unfortunately, gas does not dissolve carbon that is the byproduct of combustion. I had a piece of carbon come loose in Moab last year and you would have sworn the engine was coming apart until it passed out the exhaust valve. I’ve seen inside several under 30K mile Isuzu engines (I have 2 VX intakes in my garage) and the black coating that builds up is thick and hard and should be removed - it will not go away with over the counter products although they can help minimize it.

[andy454]

The way that our injectors are designed they really never need cleaning. If you have a gm vehicle I would never clean them. The cleaner can damage the coatings on windings and cause them to short out. Ours are a little different in that they are dry injectors. As far as the engine decarbing, it is very simple to do yourself. I recommend GM top engine cleaner. All you have to do is get the engine warm and then remove a vacuum line and suck the cleaner in. You can let it stall if you want and allow it to soak. Then start it up and watch the smoke. Make sure you do this outside. I once saw a tech do this is the shop and it ran all of out for more than an hour. As far as stalling just take a look at the idle air control valve and inspect for carbon. You can use the same cleaner on this. They also make a spray version on the top engine cleaner for the throttle body.

[dogue]

Thank you! Andy454
Your info is very helpful I will try the Engine cleaner.

[Tone]

Uh, injectors flow fuel through them that can leave deposits behind that clog them. There is also the residual mist of fuel on the tips - pull out one of your injectors and take a look at the tips. I’ve had 24+ out of engines with less than 50K on them and they are dark brown. Then spray them with cleaner and the build up that was there is gone. It is clearly visible and that does not even address the build up that is INSIDE the injector.

Build up inside the injectors causes them to stick or not atomize the fuel - HD cleaners available at the dealer, lube shops and to some, over the counter take care of that. Fuel additives also will lessen that buildup but it not the same strength as the products that attach to the fuel rails and literally fuel the vehicle while they clean (w/ fuel pump disconnected).

For more info, see:
http://auto.howstuffworks.com/framed.htm?parent=fuel-injection.htm&url=http://www.goldeagle.com/cartips/finject1.htm

[andy454]

In dry injectors I mean that the windings are not cooled by the fuel. I agree that there will be buildup on the outside of the injectors but we use a ball and seat. They can still cause some problems, but not nearly as bad as the old needle and seat type. That type needed cleaning all the time. Sure glad we got away from them. If you run a good quality fuel you should not see many problems. But things do happen. The easiest way to determine if there is lack of fuel is to use a pulse box connected to the injector and monitor the fuel pressure. When you pulse the injector you should see a certain amount of drop and compare it to all other injectors. If one is stuck you will see a difference. Not quite as good as an injector flow bench, but who has one of those.
P.S
Just talked to a senior engineer for the 3.2 vx and he agreed the design is self cleaning, but with a tank of bad fuel... could cause some problems.
My main point is just don't let the dealers rip you off saying you need one every service.

[Ironman pilot]

Bringing this old thread back, I have a question on some of the fuels with ethenal. I've been told that Costco fuel contains a good amount of ethenal as with 76. Is this a bad thing with these injectors? Just developed a problem like a lot of people here with intermittent stall on engine start. After driving with slight throttle, will clear up for a day or so. Just tried cleaning the idle control valve and throttle body plate area. I will go purchase a new ICV if the cleaning fails to cure the problem... While cleaning, is it bad to move the pintle in and out to clean the shaft?

[steelzeus]

I was always told that ethanol dries out your gaskets. its also not as efficient as regular gas is. its like 70 percent the energy that gas is. you shouldnt tell a diff in drivability. and ethanol is better for the enviroment

[Ironman pilot]

3 days so far and the engine starts and idles everytime... Prior, the engine would stall at least 2 times a day. Great info from u guys on this fix

[VehiGAZ]

Generally speaking, regional regulations dictate the types and concentrations of oxygen-enhancing additives like ethanol or MBTE, so it's probably not a "Costco gas" or "76 gas" thing. Check the pumps at several different gas stations to see what they have in them and how much - they will probably all be the same.

We used to have MTBE in our gas in CT, but they started finding traces of it everywhere in the environment, so they got rid of that junk and mandated adding ethanol up to 10%.

steelzeus is thinking that you're running pure ethanol, I think, not gas with ethanol as an additive

[Ironman pilot]

I talked to a Costco rep. He stated that the gas that they supply has about 10% to 15% ethenal. I travel to LAX on my commute to work and when I use Cheveron vs. Costco, I can definitely see a difference... The Cheveron gives me more miles.

P.S. Over a week and still running fine, no stalls. Cleaning the Idle control valve is the fix for this idle problem