SmokinRx-7

well its an 1988 t2 with an s5 jdm motor. uhhh well i changed the coolant temp sensor and it is still havin old start problems... it takes many cranks to start and when it gets close to firing it blurps or backfires lightly... but yes it will not idle cold if i let off gas it dies... then once its warm it idles at 1500 rpm then slowly goes down until it dies... it also seems running rich and lightly backfires every once and while. any problems... i am gettting a new BAC this week. think this was the problem? or is it big vacuum leak? or wat? any suggestions greatly appreciated

drakesword

Could be a multitude of things. First id say clean your engine first some seafoam. Get a buddy to keep it running and put the seafoam through a vacuum. You can remove the break booster and pour it into the line slowly. Should smoke like hell but cleans well.

After its all in cut the engin off and let it set for 5-10 mins
fire it up and drive it round till it stops smoking.

SmokinRx-7

where can i get sea foam... ?

drakesword

Autozone or advanced for like 5 bucks. Walmart if the one you go to caries it.

sharingan 19

iTrader: (16)

this sounds more electrical than mechanical.
have you pulled the spark plugs? what do they look like?
have you adjusted/checked the timing?
have you checked/tested/cleaned the BAC?
I wouldn't rule out a vacume leak either, use some carb cleaner while the engine is running to locate a leak if there is one.

SmokinRx-7

can u explain how to find vacuum leaks?... im not totally sure on how to do it... and yes im replacing my BAC right now because i know its bad. anything i should look for?

drakesword

Did you want the easy way or the cheap way.

The easy way would be take it to a mechanic.

The cheaper, and more dangerous, way would be to use some propane arround oll of your vacuum lines and gaskets. If the idle stabilizes then you may have found a leak. Fix it and do it again.

SmokinRx-7

i have to use propane? im not taking it to a mechanic thats stupid.. ive nvr taken my car to a mechanic and nvr will...cant u sue like soapy water or something to do it? ive heard?

drakesword

soapy water would work with POSITIVE pressure. But we are talking about NEGATIVE pressure. Some, erm, most of the vacuum lines on the engine are small and in awkward spaces already. Plus anything involving a gasket is likely to be hot by the time you would notice anything so the water would evaporate away.

here a page on it

SmokinRx-7

well any thing i can sue or does everyone use propane? how do u exactly do it then?

Go48

iTrader: (7)

Try spraying starter fluid or propane sparingly in areas where the vacuum lines are located. If the engine rpm increases when you spray, that's the area where you look for a leak. Or you can try spraying plain water instead and listening for a drop in rpm.

BTW, vacuum lines are everywhere in this car unless the emission control systems have been removed, and there are some that are not completely visible with the engine in a fully assembled form. So you will, on occasion, be spraying into blind areas. Check out the diagram in the FSM for info on vacuum line locations.

SmokinRx-7

ya i have all my emissions removed so should be a lil easier.. but ya so i just spray propane next to the lines and if the idle rises i have a leak? wat should i use to spray it with jsut a small propane canister?

houston93rx7

use carb cleaner instead of propane it works the same and easier to spray.

SmokinRx-7

ok ya good idea... ill def do that then