I have a weird problem. My 1990 FC tends to have like a boost cut when it reaches exactly 0 psi and after that the car backfires like crazy. The car will not have any acceleration and the rpm drops as though there is no throttle response. I have to lift the throttle off and drive below atmospheric pressure. Everytime i floor the throttle and it reaches 0 psi the same problem occurs. What could be wrong, i have changed the air flow sensor and also the pressure sensor. Checked all vacum hoses and there is no signs leaks. Weird thing is that it does not always happen and always happen only when the car is warmed up.

i vote boost/vac leak. Check your couplers and make sure they are all nice and tight. if they are, start looking for any cracks or breaks in the couplers, tubing, intake pipe etc.

i had this same problem when we converted an is300 to turbo, trying to remember what it was lol.



also what mods are on the car? stock everything or what?



kevin.

thanks for the replies. the car is basically stock. just changed to ARC top mount intercooler, added the HKS open pod filter and SSQV bov. will check to see if there is any boost vacum leak.

ive run into this on fd's, there are a couple of things that will put it in limp home WITHOUT turning on the check engine light. but it will store the code.



so check it for codes, anything where the ecu thinks it doesnt have fuel, it will turn off @0psi