86 GXL work

[murz]

Alright, well I'll be home in Michigan in 2 weeks now. That means I'll have plenty of time to work on the seven. Anyways, I have a stainless steel header, I'm wondering how easy/difficult it would be to replace the current stock manifold? In a driveway haha.
Also, I plan on taking apart the throttle body to clean it and what not and hopefully find this troublesome vacuum leak I have. Any recommendations as to what I should do while I have it apart? Besides clean and check for vacuum leaks?

[~Groll69~]

depends on the issues your having with it.  The engine mount on passenger side may need to be loosened to remove the stock header.  Then the engine tilted up about an inch.  I beleive i ran into that issue with mine many years ago.  Though somewhere along the line i did lose the aftermarket header i had for it.  I know that is going to be mildly painful to deal with.  The intake isnt much of an issue.  May want to give the engine bay a quick clean.

[murz]

Well, I'm pretty sure the 2k idle I have is due to a vacuum leak, most likely the EGR. I'm beggining to suspect I might even need a rebuild now. I have a tiny oil leak coming from one of the OMP lines as well. But yes, I definitely want to clean it all up while I'm at it. Is rebuilding the 13b something that I'd be able to do? I'm definitely not a mechanic, how-ever since owning this car I have a good grasp on things and I'm able to do things my self.

[toplessFC3Sman]

Generally if it's an NA, it's starting pretty easily and you aren't losing a lot of coolant, you don't need a rebuild.  A compression test will tell for sure.

2k idle is most likely a vacuum leak - I'd recommend taking off the entire upper intake manifold and going through to replace all of the rubber lines you see (one at a time so you can make sure you're connecting everything correctly!), since if you haven't done it already, they're probably all baked & ready to split.  Fuel line & pulsation dampener are good things to replace at the same time, and maybe rebuild the OMP lines too (only $20-30 worth of stuff from mcmaster.com - there's a thread on RX-7 club about rebuilding them using the original fittings - get new copper o-rings from mcmaster too!)

[murz]

Reason why I mentioned a rebuild is because I'm afraid it might need one. Terrible power loss right now, when it was idling normal, it was pretty rough. Either way, when I'm in Michigan in 2 weeks I'll give it a compression test.
Oh thanks for the advice, I'll definitely rebuild the omp lines then, seems easy enough. Where can I find replacement vacuum lines? I'd rather just replace them all so I don't have to worry about future leaks. Thanks for the advice!

[toplessFC3Sman]

There are lots of things that could make it lose a lot of power, and if you're worried about the vacuum lines, they're the most likely candidate for rough idle.  A compression check will tell you for sure.

Vacuum lines you can pick up at any of the auto parts chains, they sell them by the foot.  I don't know how much of each size you'll need, and it depends on how much of the original emissions equipment you still have.  The chains just have SAE (standard) sizes, not metric, but they come in close-enough increments that you can usually make it work.  Pick up a variety of hose clamps too, just to have on-hand if one SAE size feels slightly too big, but the next size down is definitely too small.

[murz]

Alright, good news is that I'm officially back in Michigan now! And damn does it feel good. Bad news, did a compression test. and the results aren't looking so great. Front rotor got 3 pulses of around 60psi. rear rotor got 3 pulses around 65psi. So if it's broken, well then time to fix it. So now, I ask your professional advice... Should I...

A.) Have it sent to a shop to get it rebuilt? Most likely Chip's motorsports. I'm looking at 1300labor plus let's say 1100 parts. so about 2400, let's bump it up to $2500 total.

B.) Order a brand new engine, let's say about 1500 or 2000? and install it myself.

C.) Order a Turbo II engine, saw one for about 1000 on JDM, with a transmission. How-ever I'd have to also buy the drivetrain and everything else for the swap... So let's say $1800?

D.) Rebuild the engine myself, in my driveway/ garage. Costing me just parts, which I'd assume could be anywhere from 1000 to $1900.

I'm unsure what to do, option A, would be the fastest route yet most expensive, option B would be a happy medium. Option C could be a long job, how-ever with increased HP. And Option D, could be the cheapest method, and I'd teach myself alot! How-ever I could potentially ruin the engine. Will take a while, even though I'll have months of time off. I have no experience as a mechanic, how-ever I have the tools, will and motivation.

[~Groll69~]

The Mazda Rx7 - Turning ordinary men into master mechanics snce 1978.....

Well I need to buy the coolant seals in order to complete a rebuild on my engine.  The choice is really a matter of what you would like to get out of it.  Install a new engine yourself (with some help) isnt difficult.  With 2 to three people, it would take about 3 to 4 hours.  as just yourself, probaly over a day.  I know i took a week when i did an engine and transmission swap from a donor car to my vert.  I also was doing a lot of work with the vert at the time too, so it took longer then planned.

[toplessFC3Sman]

From what i've heard, many times the rotary engines that you get from JDM importers (at least ones that don't specialize in rotaries) do have significant problems.  Many times they can be blown, or have stuck seals, internal rust etc.  You may end up needing a rebuild anyway if you go down path C.

How many miles are on the current engine?  What speed was the engine spinning when you did the compression test, and did you have the throttle open? Are the OMP lines full of oil/do you premix?

[murz]

Sorry for the late response. Yes throttle was open, car was warmed, omp lines have oil. I'm not sure what the actual crank speed was at, what ever stock is i'm sure.
   Well the car is driveable but really isnt. It will rev to 8000 but it takes a while to get there. It has no power,  takes a good five seconds to get moving in first from a stop. I have to have the tps un plugged, or it will try to idle at 750, which will cause the engine to slowly stall. Braking, turning the wheel, headlights, electric fan will significantly lower the rpms by about 200rpms. So from what i've read its had symptoms of bad compression before i tested it. 
    I plan on doing a rebuild (option D) myself. I have manuals and well, aaroncakes youtube videos. I will also include a porting job, painted housings, and an engine bay cleanup into it as well.
   My questions though. What else should i inspect/replace while shes open. Will i need to remove the tranny? Whats the best company to buy a rebuild kit from? I plan on deleting the omp, advice? Sorry for the life story... Also loving the master mechanic quote groll, good one.

[~Groll69~]

I personally dont care for the idea of eliminating the OMP at all.  I think it is too much of an hassle to always premix the fuel if the omp is eliminated.  porting and rebuild shoiuldnt be too difficult, though i have yet to rebuild mine myself.  I need to buy coolant seals.