Buddy is on a road trip. History of Car. LS1 heads and cam. Injectors were stockers, hp tuners found injectors too small, went to 30 lbs. car has aftermarket HV fuel pump. Car retuned, ran fine no problems, no SES. Found tb drilled in butterfly. Car ran fine all day yesterday on the highway 85 + mph. Car sat overnight. Started today, no problems, ran 55+ mph on the highway. Got off highway, running side roads, AC on. Car gets cam surge, slight black smoke, dies. Cool car down, runs fine for awhile, then same scenerio. No ses light. Let it sit half hour, runs ok. Then does the same. Again, no SES light. Car is far from home and any help would be appreciated. Thanks in advance.

 

The car is NOT overheating, correct?

 

Correct, light hasn't come on and guage is dummy anyway. Checked all the obvious with him over the phone.

 

It might be a TPS sensor.

 

I would think that a TPS sensor being faulty would throw a code. None are present. And if that also were the case, I would think the rpms would be high. This isn't the case. Car just dies for no apperent reason. No codes. Maybe it is an issue with car tuned without the AC on. I would think the tables would be different then. As said, the car had no problems after tuning until today. Only difference from yesterday to today, the AC was on when this started.

 

So can he drive it home without AC?

 

Your right ses sould have come on. And it sould come on if you have a coil prob. noid prob. no spark prob. It hard to tell with out a fuel pressure tester. You may have a fuel regulater prob.

 

Fuel pressure checked before he left. 60psi KOEO and 50psi with engine running and the pump is new.

 

Won't keep running with it on or off.

 

vapor lock? still maybe a fuel issue. you said pressure was checked prior to leaving. was the engine hot or cold?

 

60psi KOEO and 50psi with engine running. Still going back to the fact that everything was fine and dandy until the AC was turned on. I am trying to find the obvious. What was done diferently today than yesterday. The car issues came when the AC was turned on. I just got a call from him, they left the car, got down there, and then came back to pick up the car and drive it the rest of the way. They ran the car, no ac, made it there ok. Still no ses light. Does anyone on here live near the Hot Springs AK area that can reccomend a good shop? He found a local Auto Zone and is going to have them at least Scan the car. While he is there for a wek he will be doing short drives without the AC on to see if it will give any problems. If anyone could give some insight or can tell me a good shop in the area, it would be appreciated. Thanks.