Running Rich

[wadejake]

Hello, I have a 1986 BII 2.9l 4x4 xlt blah blah blah that has been running rich all winter. On start up, and while running, if you are outside the car you can smell gas, like burnt gas not a leaking tank or anything. Spurts out a little bit of black crap on cold days from the exhaust, like sooty water on start up/warm up. Before doing the work I did in the fall (Read below), on the highway I could rock somewhere around 19-22 MPG, which was awesome. Now, I'm getting like 12-13 MPG, which is sad.

Last fall, I had the ECM go out, but in the process I managed to replace many other things with no change until I did the computer lol. These things include; Injectors, Cap, Rotor, Wires, Plugs, O2 sensor, MAP, ECT, ECM, TFI, TPS all that good sensor jazz. Was not fun to do in the college parking lot lol. After finally doing the ECM, I was just thankful to be able to drive back home, so I wasn't as worried about the gas mileage or it running rich. It runs well, just rich. I'm also getting code 42c or "Always rich" when performing KOER test.

I ordered a ACT, as I have read that that could be the issue, but not entirely sure. Any thoughts, comments, or concern would be greatly appreciated, thanks for reading!

 

[Uncle Gump]

I personally be suspect of the replacement injectors you installed.

Hopefully you didn't pitch the injectors you removed and can put them back in.

Lots if horror stories about low quality injectors.

 

[wadejake]

I still have 5/6 original injectors, one broke upon removal or maybe before hand. I can try swapping them back in.

Yeah the ones I bought were the cheapest ones I could find, so would be surprised if they were anything above rock bottom quality.

Any good recommendations on replacements? Do you think I could use the OGs with one new one?

 

[Uncle Gump]

You could certainly try... I think you'll be surprised at the results.

Check local junk yards for a used set. They can be tested cleaned and rebuilt. There are also companies that sell quality matched sets. They're pricey but worth it.

Swap in the old ones and see if it's better... then formulate a plan.

 

[wadejake]

Copy that, I'll return after doing the ACT and swapping back the old injectors. Thanks for the help!

 

[wadejake]

Update:
I replaced the ACT sensor with little to no change in the running rich issue. Waiting to have a little more time to do the injectors.

When I took the old one out, I found that it was super gunked up with a bunch of black crap. I have taken off my intake hose between my air filter and throttle body and found oil in there, which feels odd and wrong. Any ideas? Could be the lines from the valve covers but not exactly sure. You can see how gross the old ones is vs the new one. Thanks for the help.

 

[wadejake]

Welp, switched out the aftermarket injectors to a set of all original, 4 that were previously in this engine, 2 from a parts engine I just picked up. Definitely ran better and not as rich directly afterward. I haven't gotten data on the MPG yet, but it seems happier with the OGs already. Another example of why not to trust new car parts unfortunately.

 

[Uncle Gump]

This story seems to be typical with aftermarket injectors.

Glad it helped...