Black Smoke after Intercooler Install - Help! (5 Viewers)

[NJ KZJ78]

Hey gang -
Yesterday installed a front mount air to air Garrett intercooler on the 1996 KZJ78. Routed the pipes through the old horn spaces and through the back. Bought a throttle adapter for the connection to the air manifold on the passenger side and it came out really clean. Pic attached.

Everything is hooked up and clamps are tight. I start her up and she has a really rough idle and black smoke coming out of the tailpipe. This never happened since i’ve owned her. I went back and tightnes clamps, and ran soapy water over pipes to detect if any leaks. Couldnt find any.

NOTE: i have an EGR delete. Removed it last year. I do not have a manual boost controller or boost gauge installed.

I am hoping it is something simple. The only thing i can think of is the intercooler is a bit more than i need, but an oversized airflow wouldnt do it, would it?

Has anyone run into this problem? Or know enough to advise what this might be or what I should do next?

Thanks guys

 

[AVL KZJ78]

Hey gang -
Yesterday installed a front mount air to air Garrett intercooler on the 1996 KZJ78. Routed the pipes through the old horn spaces and through the back. Bought a throttle adapter for the connection to the air manifold on the passenger side and it came out really clean. Pic attached.

Everything is hooked up and clamps are tight. I start her up and she has a really rough idle and black smoke coming out of the tailpipe. This never happened since i’ve owned her. I went back and tightnes clamps, and ran soapy water over pipes to detect if any leaks. Couldnt find any.

I am hoping it is something simple. The only thing i can think of is the intercooler is a bit more than i need, but an oversized airflow wouldnt do it, would it?

Has anyone run into this problem? Or know enough to advise what this might be or what I should do next?

Thanks guys



View attachment 3963024

View attachment 3963025

The presence of the intercooler circuit would not cause those symptoms, even if your IC is oversized. Any leaks at joints will only be evident under boost, not at idle or low load, and a boost leak would not cause your idle problems either. I might look into your throttle body adapter- Trundles lists it for non-egr throttle body applications, and your KZJ will Have EGR. Hard to tell from their website pics what their adapter does over the EGR butterfly in the throttle body. If it is a flat plate might it be interfering with the butterfly shaft(s) and somehow preventing the TPS from registering correctly? Also, how did you attatch the throttle linkage that used to be mounted to the crossover tube? Does your mount let the TPS shaft move correctly?

 

[NJ KZJ78]

The presence of the intercooler circuit would not cause those symptoms, even if your IC is oversized. Any leaks at joints will only be evident under boost, not at idle or low load, and a boost leak would not cause your idle problems either. I might look into your throttle body adapter- Trundles lists it for non-egr throttle body applications, and your KZJ will Have EGR. Hard to tell from their website pics what their adapter does over the EGR butterfly in the throttle body. If it is a flat plate might it be interfering with the butterfly shaft(s) and somehow preventing the TPS from registering correctly? Also, how did you attatch the throttle linkage that used to be mounted to the crossover tube? Does your mount let the TPS shaft move correctly?

Hey @AVL KZJ78 , thanks man. so here is where we are at: we bypassed the intercooler to see if the intercooler was the issue. We also did an air test and the flow was great. So we eliminate the intercooler being the problem.

Next: there is a small butterfly that remains from when we deleted the EGR system. It has two small solenoids on it. We found it was rubbing on the new trundles adapter we installed. We adjusted it slightly and even used zip ties to mimic that being removed. When we ran the engine it still emitted black smoke.

We tested for air leaks amongst all pipes. Everything is sealed tight.

We removed the new trundles adapter, and reinstalled the air intake pipe and disconnected the intercooler pipes… as if it was back to stock form. The engine ran great! No black smoke.

To your point, The only thing we are now thinking is the trundles adapter covers a small little hole at the throttle body/intake point. Perhaps the adapter we are using is the issue.

Suggest on next steps?

 

[AVL KZJ78]

Hey @AVL KZJ78 , thanks man. so here is where we are at: we bypassed the intercooler to see if the intercooler was the issue. We also did an air test and the flow was great. So we eliminate the intercooler being the problem.

Next: there is a small butterfly that remains from when we deleted the EGR system. It has two small solenoids on it. We found it was rubbing on the new trundles adapter we installed. We adjusted it slightly and even used zip ties to mimic that being removed. When we ran the engine it still emitted black smoke.

We tested for air leaks amongst all pipes. Everything is sealed tight.

We removed the new trundles adapter, and reinstalled the air intake pipe and disconnected the intercooler pipes… as if it was back to stock form. The engine ran great! No black smoke.

To your point, The only thing we are now thinking is the trundles adapter covers a small little hole at the throttle body/intake point. Perhaps the adapter we are using is the issue.

Suggest on next steps?

As suggested in your other thread, I would remove the EGR (or both) butterflies from their shafts, and if this does not work you will have to use an adapter (or cut the stock crossover) that has a provision for the EGR airflow circuit.