Running Extremely Rich

[MrFlippers]

Figured I'd get some opinions, working on my father in laws 1987 K5. It is running extremely rich at idle. Also if I drive it down the highway I have to leave it out of OD because the low RPM's in overdrive will cause it to run extremely rough, I attribute this to it being rich. Once I put it in 3rd and have the rpms up a little bit it runs just fine.

I was going to go ahead and send the injectors in to have them rebuilt/cleaned due to it sitting for awhile. When I looked in the TB with it running I noticed drops of fuel running down the sides inside the throttle body, so I figured this was the issue.

The CTS is decently new, plugs/wires/cap/rotor are all new.

Do injectors sounds like the culprit??

 

[dyeager535]

I might be inclined to check fuel pressure just because.

I had low fuel pressure, and the low pressure actually resulted in very rich running plus some real ugly low RPM performance from the engine. If you have an autozone nearby, they will "loan" you a pressure tester for free.

Injectors could drip from low pressure, clogs, or I would assume leaking injector seals.

 

[paratrooper307]

Any codes? If it's running as rich as you say, the computer should be throwing a rich code, or it could be an exhaust/or vacuum leak causing a lean reading that the computer is attempting to compensate for.

Dyeager is right, fuel pressure is easy to check and a common problem on older TBI systems.

 

[Gorillajeep]

Mine is doing the exact same thing currently. I have a new fuel pump, new MAP sensor, plugs, and temp sensor. I ma not sure where to go next. Help please?!

 

[diesel4me]

Fuel pressure regulator ?...some EFI engines use one with a diaphram that can fail and let fuel get sucked into the intake thru the vacuum hose that operates it..makes it flood at low rpms or stall,but usually you can drive it by keeping it above idle..

 

[Gorillajeep]

It;s running like it has a huge cam in it. I will look into doing this. If you are above idle it runs pretty well, but at idle and slow speeds, trail ridding and traffic, It's awful!

 

[swettysblazer]

Let me know what you find out, as I am having this same problem.