hey guys im kinda lost on this one... just did a street port swap in my jdm rx7 went from a japanese engine to a american engine(very hard to get it all wired up)... got it all running and it will start but now it likes to stalll....here are symptoms (worsen from cold temperatures)

bit of a hard start (worse in cold)
idles fine untill it drops by it self and then it stalls...it wont stall if i keep rpm up
after high speed runs it willstall as well
might have a vacuum leak(not sure yet)

other than those symptoms its fine... so im not sure what it could be im lost so any help willbe great! get back to me thanks!

 

Give us a list of any other modifications, did you do a compression check on this used engine you installed? Aftermarket ECU?

 

Have you adjusted the idle since installing the new engine. Depending on the size of the streetport it likely wont idle at the same rpm as the old stock ported engine. My streetports are not monster ports by any means bu they dont like to idle below around 1k rpms, they will, but it wont be a real smooth idle.

 

yes it was compression tested....and it was jsut done again..its is fine...the engine that was used only had about 30xxx km on it and here are mods


rebuild 3mm seals streetported engine
blitz intake
3 inch exausht minus downpipe
stock ecu
water temp and boost guage
vacuum lines redone (may have a leak)
varible fan controller(not hooked up properly yet)
re amimiya radiator
spec stage 2 clutch (under 1000km on it)
act prolite flywheel
new tranny

might have a few other things but other than that stock
other than that its pretty much bone stock

 

so could it jsut be the idel is screwed up? i still dont get why it would stall after a high speed run ?when i let off throttle

 

it seems to be worse once engine heats up as well

 

Dashpot not working correctly. I almost bet if you bump the base idle up by about 2-300rpms the problem will go away.

David

 

whats dashpot mean? lol yea like its weird it was jsut idling fine untill i gave it a big rev then when it trys to idel it jsut dies... how do i turn up the idle?...i also have another problem...my fans arnt turning on any ideas?

 

it seems liek it floods as once it stalls its VERY hard to get it back running ...so i dont know it has a stock ecu as well

 

Its the little saucer looking thing on the side of your throttle body.

 

what is? the dash pot or the idle adjuster?

 

HE is referring to the dash pot. However, adjust the idle with the idle adjustment screw which is located underneath the throttle body near the rear of it. Almost directly below the bottom rear nut that tightens down the intake elbow. You will need a short flathead screw driver to adjust it. Turn it counter clock wise about 2-3 rotations and that will raise the idle. I would continue to screw with it until you get the idle set around 1000 rpms. However, fix the fan issue before messing with the idle. Wouldnt be a bad idea to replace your spark plugs either.

 

yea well the car is acting strange once i drive it a bit it will idle at about 1100 which is where it should be..but it still stalls when i put it into neutral after going fast and being in high rpm....and then its hard to start when it stalls..i usualy just pop it back into 3rd gear to get it going again...so its really strange its still stalling.,..should i still turn up the idle? if it still happens what should i do nexy ?go vaccum leak looking?

 

like its bsicaly only stalling now at speed when i put it into neutral and roll or just sometimes if i let the rpm get to low now...so i have no idea and then the hard start after and its just hard to start period really right now...is it flodding or something?

 

A vaccum leak should not cause that. Could also be the Idle Speed Control unit going bad.

 

Try turning off your ISC unit and set idle manually.

 

ha how do i go along doing that??its so strange that it mostly happens after i drop it into neutral and the idle seems to be all over the place at times... now most of time it idles good but it sill stalls

 

to put the pfc in manual idle you have to have a datalogit, if you do, go to the idle settings and put in zero for the idle values not the F/C one because thats your fuel cut. then cut then uncheck the idle control.

 

i do not have a power fc

 

Search around on here to get a better understanding of how to properly set up the idle on the throttle body. Several good threads. Also it would be a good idea for you to download a copy of the factory service manual (FSM) that also outlines this information.

Seachable FSM: (post#10) https://www.rx7club.com/showthread.p...ght=searchable



Make sure your TPS is within factory specifications ( outlined in FSM and many places on here). Do this BEFORE even trying to adjust the idle.

Does your idle (when it does idle) surge or pulse? If not then it is unlikely you have a vac leak. What vac shows on your boost gauge at idle?

If the fans are still not working correctly I would go back and recheck all that wiring (I know wiring sucks), if they were working before and not after the swap this is the best place to start.

Hopefully this helps a little.

 

fans work when i turn ac on just not other wise... also it putters bad in idle...but its a ported engine with a big street port and it sounds like it lol

 

alright so i truned up the idle/.... about 1450 rpm... its running alot better now... it dosnt stall unless its cold ...its waming up here now so its alot better...but its still very rough..could it be a vaccuum and boost leak?

 

Its hard to guesst he exact reasons it is doing what it is, however it shouldnt need to idle that high for it not to stall. I would almost guarantee it would run better with a PFC, stock ecus dont like "large" street ports.

 

I didn't even know the stock ECU could run a street port lol. Maybe that is his problem. If the compression is fine get a PFC and run manual idle control. Would most likely solve the problem and you don't have to spend money/time on trying to fix idle control equipment.

Edit: Quite frankly I'd expect the engine to blow under boost if its running the stock ECU on a street port with a 3" exhaust...

thewird

 

yea i need a pfc im just a bit broke.. haha