when my freind bought his rx7 the original owner told him 2 things the turbo had melted and so it didnt spool up and that it had an racing beat exhaust.

a few years later(2 to be exact) my freind had to constantly push start his car and eventually it lost power and began to leak fuel

long story short
he removed the turbo and put in its place the stock headers (no piping for a turbo setup)
the problem when it does start it takes a few minutes to and once moving has no power
a loud popping noise exits the exhaust a clicking noise is also observed from the area of the air filter possibly the maf sensor and also after 3k rpm's it almost immediately dips under 1k rpms and almost turns off... what should i do???

 

This is kinda hard to diagnose because there was no 1986 Turbo model... This means that the engine has been swapped.

Swapped engine, turbo removed, and various bandage fixes mean wiring has been hacked up, there may be vacuum leaks, parts might not match properly...


How many miles on this rig?

 

https://www.rx7club.com/members/reaperfc3-121191/'
thats his profile page i think i got the year wrong lol

 

A lot more info is still needed. Converting a 4-port turbo engine to run NA is not a simple task. Were the ECU and original wiring retained? Or were NA electronics used? The original owner saying the turbo "melted" also doesn't inspire much confidence. I'd take a stab at that meaning he overboosted the crap out of the turbo, and nuked the bearings. In order to kill a stock turbo like that, you'll need to be running enough boost to blow a stock engine. Compression test the engine before doing anything else.

 

the previous owner didnt know he was supposed to let the car idle for a few minutes after driving there fore killing the turbo. the car is an 87 the turbo ecu is still being used the same wiring just turbo and the components have been removed ie intercooler. the throttle body was exchanged for an na model. on the exhaust side the piping for the turbo setup was also removed. to a regular na system.

 

You don't need to idle the car for a few minutes after driving, unless you drive at WOT into your driveway and slam on the brakes. It's a water and oil cooled turbo. Like I said before, the only way to really damage the turbo would be to allow it to spin WAY too fast (excessive boost) and overheat the bearings. A compression test still needs to be the first thing you do.

 

Series 4 (1986–1988) was available with a naturally aspirated, fuel-injected 13B-VDEI producing 146 hp (108 kW). An optional turbocharged model, known as the Turbo II in the American market, had 182 hp / 185 ps (135 kW).

 

hum the guy must have adid a number on the turbo then .
so would switching the existing turbo ecu, maf sensor to an na one fix the clicking from the maf sensor ,laggy power acceleration, and the tendency to shut off after revving over 3000 rpm

 

Please read the 2nd gen Standard Specifications sticky. The TII model was not sold until 1987. Some were produced in late 1986, but they were still sold as '87s. In 1986, only NA RX7s were sold.

If the turbo 550cc injectors were kept, the ECU (N332/333), boost sensor (N318) and AFM (N318) need to match. The part numbers I just listed are all S4 TII.