How can i tell if i have a bad motor, apex, or vacum problem? The symptons are that it has slow revs, poping in exhaust and no power. How it started?? Well i bought the car (87 TII btw) and it wouldnt idle. it would fall below 1 grand and Die. Well i got used to driving it that way. And a few days later i'm driving and i'm going about 40, i give it hell and goto 80 i slow down and pull in (seems fine) and the I shift back to 1st and its slow, has no power and wants to die on take off. Oil level was fine. I got home asked a few people what could be wrong adn they said vacum instanlty. well I checked vacums noticed a few were off and replaced them the car now idle but stil slow revs and no power and pops alot. oil pressure seems fine (according to guage) and i hear a hiss sound behind the intercooler. i cannot find the source... would this be my problem?? oh yeah and i have big feet and i dont know if this would be anything but i noticed a yellow wire coming from under the dash.. It goes into a connector with a Black and white wire, its a big connector but i think just the two wire.. i think my feet may have ripped it out while shifting... I also see lots of smoke when started and bad gas milage ( i drove it around the block a few times with 1/4 tank and now just at E) It was an all the sudden problem but it worries me i hope i dont need to replace th engine or apex seals. btw what would apex seals cost with installation?? Most people in the 2nd gen forum say vacum problem and then i read a few searches and there is a guy with a similar problem and you people say bad motor...

 

the hissing could be a boost leak, if its happening under boost. When do you hear it? A friends 89TII was running kinda strange with lumpy idle and low on power. His problem was the hose the goes from the intake to the turbo inlet was cracker up near the turbo inlet, so it was sucking air in behind the air sensor, making it run crappy. He replaced it and the car's running great. His last run...231 rwhp and 256 ft/lbs. He's got an intake, dp, mp, catback, and a redom jap spec ecu. Not sure what boost setting he had it at to make those numbers though.
Tim Benton

 

my friends cracked hose wasn't a boost leak like I mentioned that your's might be since you hear a hiss, his was a vacuum leak, but made no hissing noise.
just trying to clarify.
Tim Benton

 

the 2nd gen people now think its toast, but i Always hear the hiss not so much at low rpm. And does any one have a vacum diagram i found one for 93 i own a 87 TII the hayes manual kinda sucks