Fuel system cleaner for GM cars.

[T-Keith]

Most people don't seem to know this, but early GM multiport injectors can be damaged by most, if not all fuel injector cleaners. I learned the hard way, my 88 Grand Prix died after two injectors shorted out. A week prior I had used Valvoline fuel injector cleaner. Someone I know had his L98 injectors "cleaned" by a shop for $1200, afterward all 8 injectors shorted out. The problem is they corrode the insulation around the coil causing it to short.

More info is avialable here:
Service INFO
http://www.corvettefever.com/techarticles/153_0303_fuel/index2.html


My question is: Are there any cleaners other than GMs that can clean the fuel system and intake without harming the injectors?

-T

 

[JohnBrowning]

You know I am not saying that cleaning can not damage injectors. I can say that since 1988 when I started my aprenticeship to become a Tech. I have never seen this happen! I did not think that the coil windings were exposed to direct fuel envrionment? You would also think that the insulation would be tested against common automotive solvents and fuel chemicals. I have some spare injectors I might cut one in half this weekend to see if this is truely possable. I thought that the coils were isolated from the pintle and other parts that contact the fuel.

GM recomends the use of fuel additves and injector cleaning. They do not make their on fuel additve it is made by Chevron.

 

[T-Keith]

It certainly does happen, but only on certain injectors. GM stopped using the multitec injectors in the early 90s. I was first told this by a GM tech. He said they found that pretty much all cleaners will harm these injectors. As the link says the coils are submerged in the fuel. Supposedly the injectors never need cleaning, but they probably weren't made for ethenol fuel either. At $60+ an injector(more from GM) we need other options for keeping them working at 180k +.

-T

 

[VaderSS]

I've got multechs in the 175k '93 Olds Ciera my grandma is driving. Lucas UCL and and BG44k don't seem to have hurt them yet.

 

[JohnBrowning]

VaderSS, Would my 1997 Buick 3.8 have the same set up? If so not only have I clened then repeatedly with Lucas UCL I have also used MMO,B-12 Chemtool and X1R fuel additive. I also cleaned them manualy when I had the upper and lower intake manifold off. I am not saying that these may not be a really poor design. It just strikes me as odd that we do not hear more about it with all of the fuel additves being purchased every year by people.

I can tell you that the author lost all credability when he suggested that useing quality gasoline would solve all problems assosiated with dirty fuel system. GM has authored papers that have been published by SAE stateing that even the best fuels available lack sufficient detergents and solvency to keep a fuel system clean!

Thanks for posting the information though about this style of injector! I swear I am going to have to sell my Buick and stay the heck away from domestic products for a while.

 

[T-Keith]

No, they stopped using these injectors in the early 90s. Your car is not effected.

Anyone no about Fuel Power?

-T

 

[Bill C]

Does anyone have any information related to the oxygenated fuel causing fuel injectors to go out in GMC vehicles? My father claims his 2000 truck is having troubles since we've got this oxygenated fuel here in Chicago. He's had several injectors replaced and from what he tells me the GM dealer is replacing a ton of fuel injectors each month.

Can anyone working at a GM dealer comment on this for me?

Thanks

 

[T-Keith]

I asked Lube control about the use of Fuel power in these GM vehicles. Here are responses from Terry Dyson and Molekule:

From what we know to-date, there are no components in FP or LC that
would corrode coils or coil insulation. In fact, there are components
contained therein that would actually protect the insulation from
corrosion, IMHO.

Standing from the sideline, if indeed the insulation is melting or
thinning and the wires are corroding, it appears to be a design flaw. In
harsh environments such as automotive and aerospace applications,
special wire insulating materials must be used to insure the insulation
would not be softened or melted off by chemicals. Many times, wires are
given special plastic coatings and even PTFE is applied via spraying.

In my view, very hard epoxy or special RTV sealants should be used to
encapsulate those coils operating in a harsh environment.

Secondly, the encapsulant must be able to withstand the cyclic
temperature environment, and especially the heat environment of the
application.

IF high sulfur fuel were to somehow be sprayed onto or deposited onto
the
injectors coils with a disrupted coating, then sulfur byproducts and
other compounds such as sulfuric acids would certainly attack wires not
properly coated to resist such chemical attacks.

Bottom line, I think GM has a materials selection problem that just
surfaced!

Molakule



Nothing specifically for the multipoint FI system.

I don't believe FP will harm it. I stand by my statement that FP will
not corrode this system or any other.

Terry

I have ordered some Fuel Power and will post any results I have from my wife's 87 Riviera with 188k miles.

-T

 

[DSteven]

Another issue I noticed with the 2.8 and 3.1 MPFI engines from GM (especially 88-93yrs) were the fuel injectors go bad. The circuit opens or closes and causes a drivability issue at first, because the circuit through the injectors either stays full or closes. I would take out the injectors and use an OHM meter to test the resistence. The injectors apparently get quite hot under the top part of the intake, causing them to 'short circuit' from excessive heat buildup. The problem starts with rough idle, bad MPG, stalling, doggy acceleration, etc. Finally, the engine will not start. At any rate, this heat buildup, along with GM's poor choice of quality at times , tend to cause injectors to fail in these engines. However, ethanol gas has proven to shorten the life of the injectors, too! It has something to do with drying them, if memory serves right. This would support the problems related to the fuel system cleaners, which in general tend to be hard on fuel pump electrical components, etc. Some people utilized used fuel injectors to replace the bad ones, only to have the same issues over time. There are good aftermarket replacement injectors for the 2.8 & 3.1 that are ~$45-60/pc. The job isn't fun, but it can be done in the garage. I did it a few times. Good luck!!