2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Hello New Member/possible rx7 owner with some tech questions

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Old Jun 28, 2008 | 07:25 PM
  #1  
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Hello New Member/possible rx7 owner with some tech questions

Hi my name is Zach i live in Missouri, and im considering buying a 86 rx7. I have an A.A.S degree in Automotive Tech, and had a few questions about the car.

Now im not new to forums and have been prowling/searching to see if my questions have been answered.

We only briefly touched on wankels and what i knew before that was limited.

1. The owner says the fuel pump is bad is this a common problem? and i have read here that if you are going replace it use a turbo pump from a 3rd gen. Good idea/bad idea?

2. I read a trick about ATF and its just been mentioned in passing i couldnt find a how to. (I belive the atf lubricates stuck apex seals?)

3. The car has 125k miles was owned by an older lady and it is unmolested i belive its a base model (has 4 lug wheels) Is there anything I should know that could cause a problem right off the bat. i know to bring the basics but anything rotor specific i should know about?

4. I dont have a compression tester at my house is the PUFF test the most simple way to test compression?


Thanks for reading/responding if you do ive been a member of SUPRAMANIA for a while and ive hear you guys are equally cool and helpful.

Thanks
Zach
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Old Jun 28, 2008 | 08:05 PM
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1. Fuel pumps do go bad if thats what you mean. A 3rd gen will provide moe fuel then you will ever need to an already rich running n/a... unless you plan on a turbo swap later in the cars life just use an n/a replacement.

2. ATF is used to raise compression enough in order to allow the car to start with a stuck/sticking seal or low compression. There is some negative conotations to ATF and some people prefer to use regular old motor oil which works as well.

3. Learn deflooding procedures just in case.

4. The PUFF test is the simplest way, make sure there are three stong pulses per engine rotation. Just pull a spark plug to test.
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Old Jun 28, 2008 | 08:10 PM
  #3  
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Originally Posted by BlindRonin
Hi my name is Zach i live in Missouri
If you live near St. Louis, we are planning a meeting soon. See the Midwest RX-7 forum:
https://www.rx7club.com/midwest-rx-7-forum-32/st-louis-drunks-come-out-play-764956/

Originally Posted by BlindRonin
1. The owner says the fuel pump is bad is this a common problem? and i have read here that if you are going replace it use a turbo pump from a 3rd gen. Good idea/bad idea?
A fuel pump upgrade is common on the TurboII models which need extra fuel when modified for more boost. A non-turbo street car will probably not require anything beyond the stock fuel pump.

Originally Posted by BlindRonin
2. I read a trick about ATF and its just been mentioned in passing i couldnt find a how to. (I belive the atf lubricates stuck apex seals?)
https://www.rx7club.com/showpost.php...55&postcount=5
http://www.aaroncake.net/RX-7/atftrick.htm

Originally Posted by BlindRonin
3. The car has 125k miles was owned by an older lady and it is unmolested i belive its a base model (has 4 lug wheels) Is there anything I should know that could cause a problem right off the bat. i know to bring the basics but anything rotor specific i should know about?
FYI 125K miles is probably about due for a rebuild, which will cost over $800 in parts alone, or about $2,000 for parts & labor.

I actually like the base model because it is light and the smaller tires are less expensive. While the larger wheels of the higher end models do seem to handle a bit better, I have never had a problem autocrossing with the smaller base model brakes.

When buying an RX-7, there are actually a lot more model-specific things to look for as opposed to engine-specific things. The only thing I usually add at this point is to avoid the automatic transmission like the plague, but since you are an auto mechanic you may not mind dealing with it. This buying guide was written by one of our forum's moderators:
http://www.aaroncake.net/RX-7/buy1.htm

Originally Posted by BlindRonin
4. I dont have a compression tester at my house is the PUFF test the most simple way to test compression?
Yes
http://www.rotaryresurrection.com/2n...ion_check.html

Originally Posted by BlindRonin
Thanks for reading/responding if you do ive been a member of SUPRAMANIA for a while and ive hear you guys are equally cool and helpful.
Most noobs think we are a bunch of jerks because they don't stick around long enough to realize it is more of a "tough love" environment here. Also, this forum is so large that it contains experts from many different technical fields, so "great ideas" tend to get shot down a lot, while they would receive more support on forums with more ignorant members.
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Old Jun 28, 2008 | 08:14 PM
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Thank you for the quick response!
I would eventually want to swap, I was just wondering if i had the money wether it was worth doing the swap while I was there.

Thanks
Zach

When it comes to being in a forum community, You cant let every little thing **** you off some people are just born Jerks. I see this a just another place to gain wanted information, and help people I can. So thanks I already like what I see here!

Last edited by BlindRonin; Jun 28, 2008 at 08:20 PM. Reason: Im a dork and posted to quick!
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Old Jun 28, 2008 | 08:37 PM
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Originally Posted by BlindRonin
I would eventually want to swap, I was just wondering if i had the money wether it was worth doing the swap while I was there.
If you mean that you intend to convert a non-turbo car into a turbocharged car, I really don't think it is worth the trouble unless you simply like tinkering with cars. By the time you source the TurboII engine, hood, transmission, starter, boost gauge, flywheel, clutch, driveshaft, LSD, halfshafts, etc., you may as well have just bought a TII to start with. Also, a converted car does not have as much resale value.
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Old Jun 30, 2008 | 12:48 AM
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I do love to tinker. I really know its not cost effective i dont know if people consider the rx7 a money pit but, the supra i own is and im in the process of doing a swap for it so i know
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Old Jul 3, 2008 | 12:35 PM
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So i went and bought the car paid 650 bucks for it.





Pulled the fuel pump and found this







Power washed the tank and got most of the rust out





Had two things i dont know about



The black hose comming from the charcol canister is snapped off? where did it originally go?


and this hard tube is pinched at the end on the exhuast side of the engine has what looks like a filter connected a short way up? what is it and is it supposed to be pinched off?
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Old Jul 3, 2008 | 01:50 PM
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Tube looks like the split air pipe. Pumps air into the catalytic converter for the reaction. Your exhaust is probably not stock. A stock cat would have a pipe coming off the side pointed forward, ending with a flange to connect to that.

You might also check to see if all the air/emissions parts are still intact (same side of engine as that pipe). Depending, of course, on whether you need them.
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Old Jul 3, 2008 | 02:41 PM
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That also means your Aux Ports are either not working or have been removed, just some information for you.
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Old Jul 4, 2008 | 02:32 PM
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well i live in Missouri so i dont need to pass emmisions i do have to have a cat(or somthing that looks like a cat) to pass saftey, but no test for emmisions. so the hard line is for the cat (just an internal air feed to reduce emmisions). what about the charol line? is that an input or output? could someone link me to the Service manual please

Thanks
Zach

p.s also the exauhst is not stock its gone after the cat lol sombody cut it off
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Old Jul 4, 2008 | 02:51 PM
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Judging by the looks of that fuel pump, you may want to clean the tank as well. Couldn't hurt to replace the fuel lines and filter if possible. . . I bet theres a lot of rust floating around in there.
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Old Jul 4, 2008 | 11:27 PM
  #12  
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i did i power washed it out for a half an hour most of it came out im going to get in there with a wire brush tomorrow and finish the job.
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Old Jul 5, 2008 | 03:12 AM
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Well, you seem to have hit the ground running, that fuel tank looks horrid! Good thing you're giving it some attention.
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Old Jul 5, 2008 | 03:43 AM
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The hose off the bottom of the charcoal canister doesn't connect to anything. It just sits there zip tied to the body. I guess it's a vent of some kind.

Get those aux ports working as soon as you can, as the car will not pull the same without them. Don't want to dampen your first RX-7 impressions, hah. The split air pipe has a small vac line connected to a metal hardline, which feeds the 2 aux port actuators. They are activated by 2.1 PSI of exhaust backpressure, but frequently do no see this even with the split air pipe hooked up to the main cat properly. There are some simple ways to run them off of the air pump instead, but first just try to get them setup as stock. Without them you will lose ~25 hp due to a flattened top-end (3800 RPM to redline).
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Old Jul 5, 2008 | 09:00 AM
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^ That all depends on if he still has aux ports in it, or if they are not tied open.

Either way you are losing some top or bottom end power.
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Old Jul 5, 2008 | 09:51 AM
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That fuel tank is junk. Either have it lined, or replace it. It will continue rusting and keep clogging up the pump.

As others have mentioned, the little line on the bottom of the charcoal canister is supposed to go nowhere.

The metal tube is the split air pipe meant to feed air to the main cat and allow exhaust backpressure to open up the aux port actuators. Presumably the cat is gone. In which case you can activate the aux ports via the air pump (see Archives/FAQ).
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