so i've had an 87 TII for a couple years now and have been in the process of getting it running... i gave up on it for a while and at one point posted it up for sale but never got around to doing so. Now i'm kinda getting a second wind and want to reconsider fixing it up.

My dad and I have done a lot as far as replacing a chunk of the fuel system because the old gas tank was rusted out. The previous owner left the car sitting for about 3 years or so outside in Iowa weather... needless to say the car is not running so hot. after doing a few tweaks its probably been running better than it has in the past 3 years but i'm just wondering if it might be a vacuum issue

Symptoms:
The engine has a erratic idle, when started up the rpms will jump back and forward and after running for a bit it will sit around 1100 rpms or so. but basically the car will run for a bit and you can drive it for a while but when you come to a park and stop sometimes the car will shut off and then have difficulty restarting

I think it could be a vacuum leak but am not for sure... (just hoping that it isnt bad compression on one of the rotors) any suggestions?

also i was wondering whats the best way to check for vacuum leaks

 

to check for vacuum leaks you will need a shop vac ... connect the shop vac to the tail pipe with duct tape and bailing wire... if you have dual exhuast you will need to put a cork or something in the other muffler ( I use a banana)

lol I am just kidding... The easiest way is to get it to idle (whether it's @ 850 RPM or 1200 RPM it just needs to be somewhat even) using brake fluid with the little red tube connected squirt around vacuum lines and gaskets. when the idle changes thats where the leak is

One other thing you may want to do is replace the fuel injectors

 

For the post above. Use brake cleaner, not brake fluid. Ether (starting fluid) works much better but is also quite a bit more dangerous. You can also use a smoke machine. You can pick them up for auto purposes pretty cheap, but you can use a party fogger and pretty much do the same thing. You just plug the intake and fill the intake track with smoke via a vacuum hose.

 

oops, my bad... yes use brake cleaner

 

lol i like the fog party machine idea... but yeah i already replaced the injectors with stock new ones, so im just wondering if there is a leak somewhere in the intake. at the moment im unable to work on it prolly until the summer when i can get a chance to head back home and work for a bit but until then im just lookin to get some ideas

my friend told me that mechanics do the smoke test on the car, so pretty much im assuming they just spray smoke into the intake and look for spots to where it might come out?

 

Yea letting a car sit will really do it to the gaskets. If you do indeed have a vacuum leak due to rotting seals there is a really good chance the internal seals/o-rings are also suffering from the same fate. Same happened with me so just givin you a heads up on it.

 

vacuum leaks are usually located at places where the vacuum hoses have hardened and are no longer pliable or are cracked, at the gasket between the upper and lower manifold or EGR

when you replaced the injectors... did you replace all the o-rings (upper and lower). the lower grommets are offent over looked and are notorious for leaking if reused

do you still have the rats nest?... if so... best of luck lol

 

Foolproof vac leak finder (if you have a compressor):

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/water-sensors-water-pump-diff-models-583211/ (Scroll down to posts #11 and #16)

 

yeah i replaced each and every little annoying piece to those injectors... the old o-rings were toasted from the engine heat and the spacers between the block and the injectors were basically like rock hard little donuts... so yeah there shouldnt be any leaks in that part... plus i also replaced the egr valve too, but with a used one, so im hoping that isnt a problem as well, but i heard you could just use a plate and block it off, so does that mean the egr valve is pretty much like the appendix of engines? poor little guy

im really hoping its not the lim though cause i just had all that apart except for the lim and it looked like a bitch to take out... but unfortunately what must be done must be done...

i will update a list of parts replaced and areas worked on later today after class

 

List of some parts replaced:
new alternator
new starter solenoid
new upper manifold gasket
new stock injectors/injector seals
new stock exhaust
new o2 sensor
new shifter seals/components
new fuel filter
used egr valve
gas tank cleaned and boiled

The fuel system has been pretty much replaced and the lines have been blown clean (both upper and lower fuel rails/fuel line)