21 replies to this topic

[Alberto]

Sent my 91k mile injectors out for cleaning.  Results show that #1 and #2 were leaking.  This made me curious.  What are the symptoms of a leaking injector?

 

Thanks.

[Johnny D]

I would guess they leak.  

Next question...

J~

[Bench Racer]

http://clean.injecto...fuel-injectors/

 

I'm sure Dave Wheeler will be along shortly.

[Bruce Wilson]

If I had a leaky injector, I wouldn't eat food off my manifold, otherwise, I might not mind.  Seriously, grease an dirt are not your friend in racing, no matter how many miles on the motor, and this is a great reason #1   If it the manifold under the injectors look dry and smells like turkey sandwich, all is good!

[FTodaro]

One of my injectors had a bad seal where the injector plugs into the intake. The symptom was it would not idle smoothly, and it started hard.

[Alberto]

D'oh, guess I should 'splain this further. The injectors were not leaking externally.  It was an internal leak - presumably at the pintle.

 

If they were leaking externally, I would have observed that ages ago.

[Mike Collins]

Leaky injector (internal) means its got enough crap to stay stuck partially open...

[Brandon]

One of my injectors had a bad seal where the injector plugs into the intake...it started hard.

 

Reminds me of the punchline to a joke that goes "You blew a seal...." "No, it's just ice cream..."

[Bruce Wilson]

Well if your pintle was leaking that's a whole different problem

[Bench Racer]

TANGENT, tangent..........

 

Now if you want to stop the ice cream leak you could try:

• The fuel Injector pintle, ball or disc seat due to damage or corrosion (Not repairable, Discard Injector)
• The fuel injector pintle, ball or disc seat due to dirt (Repairable – ultrasonic fuel injector cleaning)

[davew]

Think of an injector as 2 parts.

 

Part 1 is the valve itself. This can get dirty from fuel deposits and cause blockage of the spray pattern. If the poor spray pattern is from blockage it can usually be cleaned. If a poor spray pattern is caused by damage to the mechanical parts of the pintle (corosion or physically damaged) then you need to toss the injector.

 

Part 2 is the electro-mechanical part. Electricity opens the valve, a tiny spring closes the valve. When the mechanism gets gunky, the spring can not close the valve 100% and you get a drip. The other thing that happens is the spring can not close the valve as quickly. The valve spends more open time then the computer is actually calling for and we end up running rich. Usually cleaning the injectors will solve this problem.

 

Moral of the story; Against what is logic, a dirty fuel injector flows more fuel than a clean one.

 

Dave

[Bruce Wilson]

Fuel for thought... some cylinders inherently burn leaner than others

[Tom Sager]

Good grief, the day of needing 4 O2 sensors to competitively tune the car might be here or maybe that day already came a couple years ago.  

[Bruce Wilson]

Okay, I'm going to lose my secret decoder ring for this one

 

Not exactly.  Think creatively...

[Joe Benton]

Ii've got a bad injector in my 99.  Wondering if injectors advertised as balanced and blue printed are worth the expense?

[Caveman-kwebb99]

Yes

[Joe Benton]

Yes

Where, why and how much?

[Caveman-kwebb99]

Where, why and how much?

 

balanced and blue printed on injectors is returning them to like new and comes with printout of how they functioned on arrival and how they function upon being shipped back to you.

 

a pro built motor is 5k-7k... injectors are $500 plus shipping...  if you have a clogged malfunctioning injector it can cause your motor to run very lean causing catastrophic engine wear... burnt valves at the very least.

 

I change injectors yearly as a preventative.  new injectors are just as good by the way.  I have always used Maren injectors   http://www.injector....send off again.

 

Hope that answers your question.

 

Also seen a leaking injector causea big time fire also. 

[FTodaro]

I always send mine to Dave at Advanced AutoSport.  a site sponsor.

 

He does good work and the price is right and he sends you a nice print out.

[Joe Benton]

Thank you both. That helps a lot.