400 BB Holley EFI struggle

[KramerSwinger]

Hey y’all! Got my 73 charger running painfully rich, seemingly. It’s had a Holley Terminator Stealth on a very mild 400bb for a few years, but had never really ran quite right. I’m not tuner, curious if anyone knows anyone in Houston or southern Texas in general that can get this car running right on this system. I’d hate to have to throw in the towel and go back to carb, I’ve invested too much!

 

[1 Wild R/T]

From the Holley forum.... HP Motorsports in Houston, Texas tunes Holley EFI.

 

[BeepBeepRR]

I had a rich condition. Turned out to be a bad Holley o2 sensor. Not saying that its the same problem but replacing the 02 fixed the Sniper. It was basically dumping gas because the o2 sensor thought it was super lean. Just to let you know that was the second Holley o2 sensor to bite the dust in 2 different cars. I replaced it with the Bosch equivalent and its been good since.

 

[1 Wild R/T]

I had a rich condition. Turned out to be a bad Holley o2 sensor. Not saying that its the same problem but replacing the 02 fixed the Sniper. It was basically dumping gas because the o2 sensor thought it was super lean. Just to let you know that was the second Holley o2 sensor to bite the dust in 2 different cars. I replaced it with the Bosch equivalent and its been good since.

O2 is a possibility, but a Coolant temp sensor or a MAP sensor will cause rich mixture too... As will high fuel pressure... Someone who has familiarity with EFI should be able to pinpoint it fairly quickly.... I'd start with viewing parameter's & checking fuel pressure...

I had a bad fuel injector on a Holley unit straight out of the box... I've had a bad O2 sensor & a bad ACT sensor....

On a Fitech I had a bad MAP sensor...

They could use better quality components to improve the systems but that would cut into the profits...

 

[91r/t]

O2 is a possibility, but a Coolant temp sensor or a MAP sensor will cause rich mixture too... As will high fuel pressure... Someone who has familiarity with EFI should be able to pinpoint it fairly quickly.... I'd start with viewing parameter's & checking fuel pressure...

I had a bad fuel injector on a Holley unit straight out of the box... I've had a bad O2 sensor & a bad ACT sensor....

On a Fitech I had a bad MAP sensor...

They could use better quality components to improve the systems but that would cut into the profits...

I've been kicking around the Sniper kit for my 500" stroker in my Charger, but everytime I get there, I see stories with failed components and things that make me think I am working on my 14' Challenger haha! I just can't get over that hump and love the simplicity of the carb thats tuned well for the car. I always go back to how much do I actually drive this thing and is it worth it? I get it that it will run better, but it kinda turns it into a newer ride with **** failing left and right due to the chinese quality parts these days. I love the fact you can EFI a big inch motor now though and have it run crazy good for miles and miles when doing roadtrips and such, Just haven't been able to jusitfy the jump yet on my end.

 

[6872n73]

Stuck fuel pressure register. Check the spark plugs. Did it run correctly in the past?

I had a rich condition. Turned out to be a bad Holley o2 sensor. Not saying that its the same problem but replacing the 02 fixed the Sniper. It was basically dumping gas because the o2 sensor thought it was super lean. Just to let you know that was the second Holley o2 sensor to bite the dust in 2 different cars. I replaced it with the Bosch equivalent and its been good since.

What is that Bosh p/n?

 

[KramerSwinger]

From the Holley forum.... HP Motorsports in Houston, Texas tunes Holley EFI.

Unfortunately it appears they are no longer in business

 

[BeepBeepRR]

I had a rich condition. Turned out to be a bad Holley o2 sensor. Not saying that its the same problem but replacing the 02 fixed the Sniper. It was basically dumping gas because the o2 sensor thought it was super lean.

Stuck fuel pressure register. Check the spark plugs. Did it run correctly in the past?


What is that Bosh p/n?

You can use the Holley number and cross reference it. I don't remember the number right now. Id have to crawl under the car to get the number.

I just used the holley number and searched, Bosch® - Wideband Oxygen Sensor the cost is way less. Holley o2 sensor is 132.00 the bosch is 58.00

 

[1 Wild R/T]

I've been kicking around the Sniper kit for my 500" stroker in my Charger, but everytime I get there, I see stories with failed components and things that make me think I am working on my 14' Challenger haha! I just can't get over that hump and love the simplicity of the carb thats tuned well for the car. I always go back to how much do I actually drive this thing and is it worth it? I get it that it will run better, but it kinda turns it into a newer ride with **** failing left and right due to the chinese quality parts these days. I love the fact you can EFI a big inch motor now though and have it run crazy good for miles and miles when doing roadtrips and such, Just haven't been able to jusitfy the jump yet on my end.

Here in California the fuel is so bad I've struggled with getting cars to start, whether it's a cold start after a few days or a hot restart....

Back thirty years ago I loved tinkering with a carb, trying to get everything out of it... These days I don't like leaning over a hot engine playing with flammable liquid & I don't like smelling like gasoline... Seems like gas smelled better thirty or forty years ago.....

It's nice to be able to grab the handheld, tap a few keys & change the fuel curve, idle speed, accelerator pump shot & timing all from the drivers seat while sitting in air conditioned comfort...

On the other hand yeah, I see enough issues with these new add-on fuel injection kits to where if I had a car that runs well with a carb I wouldn't be in a big hurry to change..

That said the OP has made the change, it would be worthwhile getting it sorted out properly....

 

[91r/t]

Here in California the fuel is so bad I've struggled with getting cars to start, whether it's a cold start after a few days or a hot restart....

Back thirty years ago I loved tinkering with a carb, trying to get everything out of it... These days I don't like leaning over a hot engine playing with flammable liquid & I don't like smelling like gasoline... Seems like gas smelled better thirty or forty years ago.....

It's nice to be able to grab the handheld, tap a few keys & change the fuel curve, idle speed, accelerator pump shot & timing all from the drivers seat while sitting in air conditioned comfort...

On the other hand yeah, I see enough issues with these new add-on fuel injection kits to where if I had a car that runs well with a carb I wouldn't be in a big hurry to change..

That said the OP has made the change, it would be worthwhile getting it sorted out properly....

Agree 110%!

 

[1 Wild R/T]

@KramerSwinger
Just did a little more searching.... Might try contacting these folks... I know nothing about them but Holley lists them as an installer...

 

[beanhead]

We've used 'Mad Science Motorsports' (remotely) with excellent results..he's in Texas.

 

[69ChargerR/TSE]

We've used 'Mad Science Motorsports' (remotely) with excellent results..he's in Texas.

Mad-Science Motorsports