Everyone plz try to bare with the lengthy story, it is the only way I can exlpain but first I will tell you mods and all new parts. 94z28 A4 lt1-heads/cam/edelbrock intake/ twin58mm TB/LT-true duals-CAI/1.6 Scorpion RR-Self Tuned (with a wideband)-New Fuel pump with booster and relays. New coil and ICM 2 months ago with the proper thermal grease/ new spark plugs/ wires are about 6 months old none touching headers or burnt or cracked. Opti is about 2 and half years old ( No oil or coolant on it dry as can be) Opti harness is perfect/new pcm(retuned ofcourse). OK now to my problem. Last week took the car from Miami,FL to Gatlinberg,TN on a trip to Drail Tails and Devils whip to enjoy the newly lowered car with "some" suspension done. After a 5hr trip out of Fl right when I crossed into GA the car just completly bogged out on the highway @70mph cruise control. Pulled over waited less than 5 mins and turned back on and ran great from GA to TN. Next day take it for the roads and after 5+ hrs of hard driving, same thing bogged out ( waited 5 mins turned back on then did it again after 15mins then took me home perfect with some slight stumbles. Next day Drove it hard for 1-2 hours ran perfect!! Third day took it out after 4-5 hours hard drving bogged out about 6 times, I just kept turing it back on each time, then ran great on the highway back to the cabin with slighyt missfire/stumble under low loads. Next day leaving for Miami ran great for first2 hours then started missing and stumble but didnt turn off till I got to GA then never did it again but did miss here and there the rest of the trip back to Miami. Can someone guide me on what might be happening?? Runs great here at home no missfires no stumble stays on ( normally dont drive the car for more then 2 hours here at home).

 

had a problem similar to yours and turned out to be an oxygen sensor. seemed to like run out of gas and die, pull over and restart and back on my way.

 

First things I would do is scan it for codes.

What is the "booster" on the fuel pump? Do you mean something like a Kenne Bell Boost-A-Pump?

By "bogged out" do you mean it lost power but continued to run, or simply shut down?

 

Ok I will look into the 02 sensors as one of them the ground came off and I kinda have it sodered on. No codes and the booster runs from the ALT to the connector behind the back seat under the car I ordered it from jegs (capers brand) and bogged out as..the motor shut off little by little and if I gave it gas I'm the process just made it shut down faster. Thanks for the replies guys.

 

Is it the Caspers V-Plus Volt Booster?

Specializing in automotive interconnect and wiring systems

http://www.installationinstructions.com/102131.pdf

If so, that system shows on the Caspers website that it boosts alternator voltage 2.2V above 70% throttle. And the install instructions show it tying into the alternator output, and affecting the voltage of the entire electrical system, not just the fuel pump. But you indicate yours is wired to the "the connector behind the back seat under the car" which sounds like the fuel pump connector, and seems like possibly a different device.

Is it possible to bypass the booster temporarily? Could be an intermittent problem with the booster, or a heat soak problem.

When you indicate "No codes", is that based on actually scanning it for codes, or based on the SES light not coming on?

 

No codes as In I've used a scanner, and it is the caspers "Hot Wire" kit
Caspers Electronics Fuel Pump ''Hotwire'' Kit - JEGS

I think I can temp bypass it, I mean its never happen before and she runs perfect here at home with day to day driving of all kinds ( Granny driving-Spirited-Hard)

 

Probably no way that could "heat soak"..... it's just wiring. The other device had electronic components.