So i just bought a 1987 turbo 2 rx7. Its a hard starter, but thats nothing new to me, i had a previous rx7 that would sometimes give me a headache to start it. but this one it will rev all the way up not in gear, but in gear at around 5000 rpm it spits and sputters.... Heres a link to a video of it doing it and a video of a walkaround and revving it right up with no problem....

and for a background, when i picked it up, it would idle like ****, up and down non stop, but i drove it two hours home and now it purrs like a kitten.... it also hadf to be push started when i got it, and now it starts right up... all solved simply by driving it two hours home....



the videos might not be watchable for a little while since i just uploaded them....

 

check plugs, coils, wires. see if the coils are cracked, see what your plugs look like (color), and wires may be junk too. depends on how it was taken care of

 

i was wondering if that is what it does when theres no exhaust, i heard the fuel cut will kick in because of raised boost pressure.... but i dunno.... wires look relatively new, i have to pull the plugs though

 

yeah check your plugs. make sure you have 2 leading plugs and 2 trailing plugs. they have 2 different heat ranges. if theyre a light brown/coffee thats ok, if theyre white you have a coolant leak, if theyre black your running rich/bad timing. make sure your coils arent cracked.

and when you say no exhaust...like from the downpipe there is nothing?

 

yeah there is nothing after the downpipe, and in first gear it will rev all the way out, my buddy wanted to go for a ride and check it out, and first gear it would pull hard all the way up the revs to redline

 

but everytime in second gear it would do that sputtering at 5 grand

 

make sure your catalytic converter isnt clogged either

 

there is no catalytic converter

 

there is 2 catalytic converters...one that is part of the downpipe and the other has your split air pipe on it. check your plugs, check your coils and then look towards fuel.

 

no seriously... there is no catalytic converter on my car, just a downpipe, and the rest rotted off and is gone, it must have a test pipe on it or something, but the o2 sensor is on it, but no catalytic converter

 

i just saw the one in the back of the car during the video. unless someone replaced your downpipe, there is a catalytic converter there

 

man...... there is no catalytic converter lol maybe i'll take a picture tomorrow to show you

 

I suspect weak pump or clogged fuel filter, and depending on how long the car sat before you picked it up, the injectors could be gummed up/ partially clogged. But start with the generic rules for a "new" used car. Replace fluids, plugs, wires and fuel filter, and in Rx-7 case...check/set tps and timing... and go from there

 

but see my main question that none of that answers is why does it do it in second gear and not in first, or parked? and has anyone ran in to a fuel cut at too much boost? I will check all that undoubtedly, and thanks for the suggestion

 

doesn't look like fuel cut to me, sounds like a secondary injector is cutting out.

try putting the cat on and see if that makes a difference, if it is fuel cut it will prevent it by limiting boost. you shouldn't be running the car with an open downpipe that hard anyways on a stock setup...

 

i'm going to be ordering an exhaust system tonight actually, so ill post sometime after i put it in and see how it goes from there.

 

I would suggest new fuel filter and have injectors sent out for cleaning. ALong with full tune up.

And If you bought a 3" exhaust system with no cat- I would suggest FCD , 720cc secondaries, and a FPR.

 

Because in 1st and in neutral, there is no real load. it doesnt require any substantial fuel flow or amount in neutral to rev to 7k, and first gear usually pulls fast enough through the rpm's to not show fuel starvation. 2nd gear and up put the engine under a heavy load for longer, where fuel issues will start to show their ugly little head.

I also agree with the reference to the open down pipe on stock management/fuel system... especially on a S4 , thats a big NO NO. S4 turbos have tiny ***, not even good enough for stock, wastegates. open up the exhaust from stock even a little bit, boost creep starts. An open turbine outlet is likely allowing boost to jump way outta bounds for the stock computer/fuel system to handle (which will also crop up the same way fuel starvation can. boost wont build up enough in neutral or 1st to cause a cut, but 2nd and up will)

either way, sort it out before you need to start looking for a new engine :O

 

i have a m2 single exit exhaust and a magnaflow cat coming, might be as long as a week... but i'm looking forward to it, i know its not dual, but **** man, what a price difference and its still stainless steel

 

i will be doing a full tuneup and everything once the exhaust is on

 

so i got my catalytic converter, and now it boosts all the way revs right up, no problem!!!!

 

but now another question arises... there is no air pump connector on the cat.... what should i do? weld a thing on there to connect it?

 

if it has no plumbing then it is likely a metallic substrate which uses no air injection, or it is the wrong cat which you need a 3 way down there.

 

yeah, im sending it back, going to get the right one