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Old 09-18-14, 01:29 AM
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Engine running rough

I just needed to vent most of all, but other than that, I just bought an RX-7 and glad to be part of the community, now onto the real problem. Sorry for long post

Ok, so when I bought the rx-7, it had a busted radiator, but when the guy started it up, it fired right up and such no problems, therefore I thought it had no problems. so I drove it home for about 30 miles, stopping every few miles no more than 5 to refill with water, also turned it off at every red light. At one red light it wouldn't start for about 2 minutes I kept cranking it and it backfired some and eventually started, but wouldn't idle unless I gave it gas (Only on start up, it did not stall once it has been running for a minute.) Then once I got up to speeds of 50+ mph, I got a death rattle from the steering wheel, it shook 10 degrees to the right and back. At this moment I was scared as hell (later on I checked out the body and it seems straight, so probably an alignment issue.) So I let my friend drive it and I saw that the whole right side body flexed a little consistently with the wheel shaking, once again, this could by an alignment issue. So continuing with that, once I got it home, I tried to turn it over but it didn't want to run. So after numerous attempts we pulled the plugs and un-flooded the engine, heard constants "psst's" and it still didn't start, 10 minutes later I tried again and it started like nothing, with a huge cloud of smoke. Ill end this here, moral of the story I am doing a rebuild and I am scared as **** to open it up, because of the things I read about broken apex seals. Any input on this?

(Btw, it does need a rebuild, I turned the car over many times with some really hard starts, and the cloud of smoke is consistent with what the signs of blown water seals. Also may have broken apexes, which I am scared to even see.)

Video:
Rx-7 revving!

Throwing in a pic of my work so far, so the thread isn't all words.

Last edited by Chillichinchilla; 09-18-14 at 01:43 AM.
Old 09-18-14, 07:13 AM
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Man... I hope the car was cheap, this sounds like a nightmare!!
Old 09-18-14, 09:36 AM
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You could have easily overheated the engine in the process of driving it home.
Old 09-18-14, 10:24 AM
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Yeah it was fairly cheap and i probabby did overheat it, no worries i am rebuilding it anywho, perfect time for a streetport
Old 09-23-14, 12:37 AM
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Bump! Done a lot more work and engine is ready to be pulled! Question, any way to test an OMP malfunction with it off the car... Just noticed a lot of oil around it and may be clogged up? Also more paranoia kicking in about bad OMP's and fried ecus.. god dammit.
Old 10-16-14, 02:05 AM
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Im taking my sweet time on the rebuild... But just today I took off the oil pan and noticed the rear housing had a crack on the bottom "Dont know how far it goes yet" But I found it odd that the coolant leak was coming more from the front housing. odd.
Old 10-17-14, 04:23 PM
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welcome to the board.

as said before, you probably overheated it (and i would say "again" because my guess is the PO overheated it as well). you may end up needing to look for housings, rotors, etc. you may even need another engine altogether. good luck with project and make sure to post autopsy photos.
Old 10-18-14, 11:51 AM
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Yeah im going to post pics, im slow on rebuilding this car, but as an update im thinking of buying a tii engine and trans all together and forgetting about the rebuild for this year.
Old 10-19-14, 11:09 AM
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BUMP!
I did my research and the s5 t2 swap would be straight forward. Can anyone provide a trustworthy source for an engine? I have a few sources but not sure if I can trust them. Also if I were to decide just to get the rear rotor housing, how much should I expect to pay?

By the way here is the RX7
Old 10-19-14, 11:48 AM
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Originally Posted by Chillichinchilla
Can anyone provide a trustworthy source for an engine? I have a few sources but not sure if I can trust them.
what is your working budget (not your absolute budget)?

as i understand it, there are still a handful of solid import places around (i can't name any off-hand though because i was never really interested in them) but the likely scenario you're looking at is a rebuild even if you buy it from an import house. factor that in.

that said, you can check with Rotary Resurrection and see if he can do anything for you.

Also if I were to decide just to get the rear rotor housing, how much should I expect to pay?
you can check ebay. to be fair though, i don't see many S5 housings, but if you can wait a while, they do pop up every so often.

overall though, and depending on source and condition, you can pay anything between $30 and about $125.
Old 10-19-14, 10:04 PM
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My budget for engine is about $1500 give or take. I am around the Chicago area if relevant and thanks for the pricing on the housings, I had a friend tell me I shouldn't pay more than $50 bucks for them, but on ebay there are 2 up for which I bid 75 bucks but was still declined. Also I was looking for a running T2, I would possibly replace coolant seals and put everything else back together as I still need (Want) to upgrade to lsd. But I am aware that I will need to pull the engine and do the rebuild eventually, I just want to put it off until next summer.
Old 10-21-14, 02:36 PM
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well, as i said, they don't come up very often and chances are they will be aptly priced as such. so i wouldn't hold my breath to find them really cheap ($50 or less). however, it doesn't look like time is a factor for you with your new plan. so that works in your favor.

if worse comes to worst, you can always sell your good housing and buy a pair of good S4 housings.

as for your friend's advice, most people appear to find things better than i do, so maybe he's used to finding ridiculous deals. for me, if you're going to set a limit for a GOOD housing, i would raise it to $75-80-ish for an S5 housing. i think that may be more in line with a likely scenario.
Old 10-21-14, 09:36 PM
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yeah I dont mind the extra, my range for a s5 housing is $50-125. give or take but meanwhile I would much rather put in a T2 swap, so if anyone has any good sources, post them up. Looking for an S5 T2 engine and ECU. Wold also be willing to take the LSD as well.
Old 10-30-14, 11:57 AM
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Little update!
Took apart the engine. Need new intermediate and front irons. IF ANYONE HAS THESE FOR S5 RX7, MESSAGE ME! Housings seem fine, some flaking on one edge near the exhaust port. Might consider resurfacing.

Old 10-30-14, 12:47 PM
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The water jackets on that housing look goopy.. Is it possible that you mixed two incompatible coolants? I had this happen on a b6 A4 that my brother borrowed.. The sludge looks awfully similar =/

Good luck with the build/rebuild/swap!
Old 10-30-14, 08:39 PM
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Originally Posted by Havok253
The water jackets on that housing look goopy.. Is it possible that you mixed two incompatible coolants? I had this happen on a b6 A4 that my brother borrowed.. The sludge looks awfully similar =/

Good luck with the build/rebuild/swap!
Sitting and unregular coolant changes can do the same thing
Old 11-01-14, 05:25 PM
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Its probably a mixture of leakstop, running water through the engine instead of coolant and some other ****. I will be cleaning those out.
Old 11-06-14, 07:38 PM
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BUMMP! Dont mind the dust and dirt on them, haven't cleaned yet. So are these housings in need of resurfacing? Or will I be fine, no gashes, just some flaking on the edges. a lot near the exhaust port and sorry but not a flat spot in the garage, but they line up. Also this thread seems to be more of a build thread now, so if it could be moved that would be great, if not ill start a new thread. If anyone wants to help out, I need s5 6 port rear and intermediate plates! I definitely need those, if you can toss in the front one as well, I wont need to resurface mine Message me or reply to the thread! LASTLY! I think I may be bridgeporting the engine. To my understanding I need bigger injectors and a standalone, anything else would be an extra if I am wrong, correct me.


^Looks worse in pictures, can barely see those marks when seen in person.





Old 04-08-15, 03:17 PM
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OK! so this relates to engine running rough... I just rebuilt the engine, drives fine, good compression, sorted out most of the issues, now I have a few problems...

1. I hear a clicking from around the ACV area, I suspect the valve in the ACV is hopping around, I will check that later.
2. Terrible idle. I could not find a solution for this through the search function, I think my case is a little unique. My car idles around 1100, but the tach also wanders. It would go down to about 1050 and go back up then it would go up to 1150 and go down these are estimates. It is random, but pretty much continuous. Also, when I try to start the car when cold the car will jump up to 1500, hesitate, but stay there for about 10 seconds, and then go down to 750, idle rough and stall. (I have to press the gas for a little bit to bring it to 1000 so it doesn't stall.)

What I have done:
-Sprayed vac hoses with a water spray bottle, no bucking.
-Adjusted the TPS, I couldn't get a perfect setting as 11.30V on one side was the closest I could get to 12 and about .1 on the other side was closest I could get to 0. My idle speed screw is already bottomed out, so I can't lower the idle.
-Premixed some (lucas semi-synthetic 2 cycle) and smoke started coming out of exhaust, mostly on cold starts, but it will occasionally make a pop sound and a puff of smoke comes out, smells like premix and gas. So I suspect car running rich as well?


Help me out guys so I could get this thing registered and running perfectly. My last option is to get it registered running terrible.
Old 04-08-15, 06:31 PM
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you adjusted your TPS WAY wrong, you need to get the engine HOT hot, than adjust it to 1v
Old 04-08-15, 06:52 PM
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Originally Posted by Chillichinchilla
OK! so this relates to engine running rough... I just rebuilt the engine, drives fine, good compression, sorted out most of the issues, now I have a few problems...

1. I hear a clicking from around the ACV area, I suspect the valve in the ACV is hopping around, I will check that later.
2. Terrible idle. I could not find a solution for this through the search function, I think my case is a little unique. My car idles around 1100, but the tach also wanders. It would go down to about 1050 and go back up then it would go up to 1150 and go down these are estimates. It is random, but pretty much continuous. Also, when I try to start the car when cold the car will jump up to 1500, hesitate, but stay there for about 10 seconds, and then go down to 750, idle rough and stall. (I have to press the gas for a little bit to bring it to 1000 so it doesn't stall.)

What I have done:
-Sprayed vac hoses with a water spray bottle, no bucking.
-Adjusted the TPS, I couldn't get a perfect setting as 11.30V on one side was the closest I could get to 12 and about .1 on the other side was closest I could get to 0. My idle speed screw is already bottomed out, so I can't lower the idle.
-Premixed some (lucas semi-synthetic 2 cycle) and smoke started coming out of exhaust, mostly on cold starts, but it will occasionally make a pop sound and a puff of smoke comes out, smells like premix and gas. So I suspect car running rich as well?


Help me out guys so I could get this thing registered and running perfectly. My last option is to get it registered running terrible.
If the coolant is above 60 degrees or so then on a cold start the engine should rev to about 3000 rpm for 17 seconds before dropping down to about 1500 rpm. This high rev idle might be disabled on your car.

There is a fast idle system such that on a cold start when the idle is at 1500 rpm it should very slowly drop to 750 rpm and the drop is a slow gradual drop (takes many minutes to occur). You might not have the system set up properly or it is completely removed. If removed you will likely have cold start problems for it's the nature of the beast.

Many will state that a high idle on a rebuild is a good thing until the engine is broken in and the idle should be maintained at around 1100 rpm until the engine is ready to accept a normal idle speed.

To set the TPS you look at the Green/Red wire of the TPS and you measure this G/R wire and it should read 1 volt w/key to on and the engine as hot as it can possibly get, which requires a 20 minute drive to do so. One thing about setting the TPS is that the idle speed needs to be under 1100 rpm when doing so.

There are two solenoids at the ACV. You have the relief and switching solenoid. An incorrectly set TPS could cause this clicking.
Old 04-08-15, 10:01 PM
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Iduley the engine was hot, and I was using the FSM way of setting the idle. and satch I have no clue why my car wont jump up to 3000. I mean the person before me did block off 2 nipples, but I have no clue what they do and couldn't trace it via the rats nest diagram. I may have hooked up the thermowax the wrong way?
Old 04-11-15, 07:41 PM
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Ok so I tightened up the intake a little more, cleaned out the acv valve, put everything back a little more snugged up, and I still have the same issue but now its more consistent, this is what is happening:at start it does rev up to about 2.8K Rpm's then after about 15 seconds it drops down to 1200 and then it rises to about 1300~ and drops back to 1200 it happens very quickly, it takes about a second, it goes up to 1250-1300 and if you were to snap your fingers it drops to about 1200. that's how quick its happening.

I bought 2 cigars and blew into the brake booster hose and I didn't see smoke coming out anywhere.

I am not sure what to do anymore :<.
Old 04-22-15, 09:01 PM
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OK! Update... I found the vac leak, it was coming from primery injcectors, so, all 4 new injector o-ring kit and vac leak is gone, but now my car is exhibiting different behavior. OK I did everything according to FSM/other guides, grounded the diagnostics connection and set Tps to 1 Volt (Car warm), checked for inconsistent volts with throttle depressing and all was A.O.K. Start the car up, she will idle at 3000 for some, then drop down to about 1100 slowly, then proceed to move to 1300 and surge between 1300 and 1500. With the idle speed screw all the way down she will idle at 1200 +- 100 RPM "dipping". With the TPS unplugged she will idle at 1100 RPM with some inconsistency. Have I just confirmed a bad TPS? or should I test something else.

This is what is happening:

Not my video btw, but exactly the same thing as he describes in description, and same noise (Surging and stopping)

Last edited by Chillichinchilla; 04-22-15 at 09:25 PM.
Old 04-23-15, 01:40 PM
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TPS cannot really be set w/the idle above 1100 rpm or so. The idle adjust screw should be adjusted after the initial set coupler is jumpered as this takes out the BAC from interfering w/the process. The fast idle cam should keep the idle close to 1400 rpm before slowly dropping to a normal level. When the idle drops to the lowest it can get, what happens if you manually try to close the primary throttle plates closed. You can access the rear throttle linkage and press downward on it and this may drop the idle speed. It's possible that the fast idle cam is not working properly as it helps to slowly close the throttle plates.


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