pistole

Hi.

Posting here from Malaysia and I am really glad to have located this Forum. Great info available.

I am currently looking seriously at a 1993 3rd Gen RX7 (Touring) , manual transmission.

The car still carries its original silver paint and sports 18 inch Sparco rims all round and has (with my unfamiliar eye view) minimal mods done , what I could see were :-

1. HKS Turbo Timer
2. Rims / tyres (Sparco/Bridgestone)
3. Exhaust rear muffler (Dragger).


When started from cold , its DOES NOT do the 3,000 rpm deal. What it does do is it immediately settles at roughly 900 rpm and then BLIPs BLIPs BLIPs the throttle to , say , 1,200 rpm intermittenly , about 5 times. Then the blipping stops .... the engine idles fine at all times. This does not appear to me to be a Fault but seems to be a deliberate mod/spec that is unfamiliar to me (from reading the various RX7 info sites). Does anyone know what this "Blipping" is ?

There is a bit of whitish smoke from the exhaust from cold , then slowly diminishes but does not go away completely. After the test run (including Freeway 100mph + runs) , the exhaust emits a bit of blackish smoke instead.

The clutch is heavy and very "Grabby" , is this normal ?

I checked the water in the coolant tank and also the one on the engine itself , there is that usual , I think, rusty gunk , but is not oily. The engine oil is also water free.

I waited for it to come up to operating temp (mid needle) and the oil pressure gauge showed a healthy reading (about 1/3 from bottom).

I took it for a test run. Stop start traffic was not easy due to the weight of the clutch , the transmission was very positive. 4 - 5 shifts is clean but 1-2 shifts is a bit clunky.

The engine is a bit rough going up from idle to about 2,000 rpm , can see the hood shaking........

Coming on to freeway ramp, I was in 3rd (about 3,000 rom) , I mount the ramp and floor it onto the freeway , the acceleration is PHENOMENAL ( please note that I am talking from having grown up on a diet of late model volvos , eg , 240/740 and an off road Isuzu Trooper) , the engine pulled very strong up to about 5+++ rpm , I felt the second surge at about 4,500 rpm and think that that was the 2nd turbo coming on ( correct ? ).

I was not able to source a Boost Gauge in time for the test so can't confirm the 10-8-10 cycle.

Suspension has a very tight feel to it and at about 80- 100 mph , no problems with the car's handling.

Coming back onto normal roads , the car behaved okay , the temp needle did not move at all.

Back to the yard , the engine settled immediately back to a steady idle. No apparent oil leak from the engine/turbos.

Still has its original plastic AST.

Mileage : about 30,000 miles (!).

Service history is NOT available.

Conclusion : What do you guys think about this car from my brief and less than complete description ?

My only real complaint is the 'grabby' nature of the clutch and also the engines roughness picking up from idle. Is this normal ? If not , is it something that I should be worried about ?

At freeway speeds , the engine is silky smooth , though.

Your kind view and comments , very much welcomed.

Thanks.

zmarko

The stock water gauge is garbage, don't pay attention to it. You need an aftermarket water temp gauge to be able to tell anything about underhood temps. The stock gauge won't budge until it's too late. I'd also try and get another test drive where you CAN hook up a boost gauge and check the boost pattern (you don't want to be replacing turbos soon after purchasing the car).

I'm pretty sure that the "grabbyness" of the clutch is common among FD's. Mine has an ACT 2600 in there and is very grabby, and if I remember correctly, my last FD's stock clutch was grabby too. I'll let some more experienced members help you with the rest of the stuff.

What's the price on the car?

particleeffect

well, if it's the original engine, no matter the miles, the vaccum hoses, and posibly coolent seals are ready to go.

aftermarket clutch maybe?

yes there should be a slight kick at 4500 IF the turbo control system is working correctly, that's when the secondary comes online.

the engine won't rev to redline at start if the car is in gear, the throttle is blipped, the AWS has been removed, or it has an aftermarket/later model j-spec ECU.

turbojeff

iTrader: (30)

Good write up.

The "Blipping" of the rpms sounds like it could be normal or may just be the TPS need adjustment.

The coolant description and the smoke worry me a bit. The coolant shouldn't be rusty looking and there should be no lingering smoke after startup. Rotaries typically smoke a bit when started, it should be a bluish smoke but since it is thin it appears white.

The mileage is low.

Vacuum lines ARE FINE if they are original, someone (above) is quoting internet misinformation. Stock vacuum lines when old and hard are usually glued TIGHT to the nipples they attach to and don't come off. The problem comes when they are removed and replaced, the line does not seal well again to the nipple.

Clutch...

Heavy? Well the stock clutch is pretty light but depending on what type of car your coming from it may feel heavy.

The 1-2 shift, FD trannies are a little notchy, rev that sucker to redline and do a quick shift from 1-2, the syncro should not grind.

pistole

Thanks ALOT for your kind replies.

Yes , the mileage is 'unusually' low ........ no comment there since these cars are , by nature , not 'everyday' drivers.

The car is indeed a Japanese import , so that may account for the different warm up procedure (I am not sure on this though).

As far as the price is concerned , for me to convert the price into USD would probably not have any meaning for you guys from the States , but for just for curiosity sake , its about , converted , USD10,000-00.

What impressed me was the general 'tight' feeling of the car (suspension , gearbox and steering) , it felt connected and gave me that 'in control' feel. I compare this to my Volvos and well ..............

Before this car , I had also tested a Honda/Acura NSX (3 litre , auto). The NSX was more 'refined' in the way that it drove but comparing acceleration , the RX7 is a real 'animal' and is more of a driver's car , IMHO. I passed over the NSX because it was over-budget and also , it was an accident vehicle (the slap-dap aluminium alloy welding work was too evident).

This RX7 will be a weekend 'toy' for me , if , I decide to purchase it at all. So my initial mechanical evaluation is presupposed on this.

I have also been advised here locally that if I am ever in need of an engine/turbo rebuild , its not worth doing it with new parts , since a HalfCut car imported from Japan is readily (and cheaply) available. So , all that is needed is a complete engine/transmission transplant from the 1/2 cut into my car , that and I will have a complete , left over , front-end to source for spare-parts (!).

I have checked out Pettit's website and their work is very nice. But ...... it would not be practicable for me to ship my engine over there for rebuilding.

Again , my only reservations about the car is :-

1. the 'grabby' clutch,

2. the roughness from idle,

3. as pointed out above , the rusty nature of the coolant.

4. the throttle 'blipping' which does not seem to come out in any of the RX7 literature available on the net. Sorry , I do not know what is a "TPS". Is it a "Throttle Position Sensor" ? From all the Bosch Motronic systems that I have messed with in my Volvos , this sensor is a simple micro switch that is actuated by the throttle barrel as it rotates off from the idle position. Is this the same in the RX7 ? I know that if the switch is not 'kicked' properly or is misaligned , the idle will go a bit wonky and when there is load (eg , AC , lights etc) , the engine will not idle properly as the auto-compensation does not get to work.

I am almost ready to take the PLUNGE .......... I am just going to try to take a few dollars more off the price for the small items that need work , eg , the passenger outside door handle not working , both headlight covers blown off ( I am told that this is common for RX7s...... ), a bit of small paint chipping ......... thats about it.

Any final views are very much welcomed.

Thanks again.

particleeffect

then why would anyone ever do the hose job unless they were rebuilding the engine? don't the stockers, after all this time, tend to crack and split on there own due to all the hardening?

SpeedKing

iTrader: (4)

Did you read the part about the car only having 30K original miles?

pistole

From my experience with vacuum hoses generally , if its exposed to heat AND is subjected to movement/vibration, they will tend to harden , then crack ..........

IMHO.

pistole

Yes , the mileage is very low and from my cursory 'squeezing' of the various exposed hoses (both vacuum and coolant) , the rubber is still youngish and is certainly not 'hard' nor is it 'brittle'.

I have made the Dealer an offer for the car. We'll see what he comes back with.

If I take up this car , I will probably leave the vacuum hoses as they are since it seems to be working fine but will change a complete set of coolant hoses for safety.

Thanks again for the kind input.

scotty305

iTrader: (2)

If your car was imported from Japan, it's very likely that it has an aftermarket clutch installed. From what I hear, this is a pretty typical modification in Japan. Having blown-off headlight covers would make me think the car has seen its share of racing after dark.

It seems like you've done plenty of reading about RX-7's. You know they need plenty of maintenance, right? A grabby clutch can be changed out, it's somewhat expensive though. I would be wary of the rough idle. Try to have a compression check performed, if possible.

-s-

SpeedKing

iTrader: (4)

The vacuum lines should be fine for a long time. Those, like the stock radiator and AST which seem to be replaced fairly often around here, are generally high mileage wear items. All of the above shouldn't be an issue for now.

BTW, when you change the all the coolant hoses, while you're in there, it would be a good idea to replace all of your belts at the same time.

particleeffect

millage doesn't mean nearly as much as how many times the engine has been heat cycled, cold started, or how it's been taken care of.

the hoses and coolant seals may be perfectly fine, just don't take millage as gospel and don't take the buying price as anywhere near the ownership price. it IS a used sports car after all.

pistole

Hi.

Yes , I am also a bit worried about the roughness as the engine lifts off from idle ( at idle itself , the motor is very smooth ).

I understand that this could be caused by a whole gamut of reasons (old sparkplug cables , bad plugs , insufficient engine grounding ....... etc ) down to mechanical problems (eg , something out of balance , eg, flywheel , clutch ...... ).

The suggestion for a compression test and also the boost (10-8-10) test is noted. Thanks. I will try to wrangle another test drive later on today / tomorrow ..... if I can escape from the office early.

One thing though , I believe that a 3rd Gen RX7 is probably , stock , the best bang for your buck as far as performance is concerned.

Over here , our cars must pay "Road Tax" and also insurance each year. Both are sums calculated on the CC of your car (the more capacity you have , the more you pay .... above 3,000 cc , it gets astronomical).

With this rotary , its classified as a 1.3 and therefore , its very cheap to run and insure. ( If you can't tell yet , I am desperately seeking reasons to buy it ......... ).


Speedometer
____________

The stock speedometer is rated to max , 180 kmh (about 120 mph). Is this original spec ? With the 18 inch rims, I have no idea whether the speedo still reads correctly.

Thanks.

PVerdieck

Hmm.

When you did that highway blast were you able to take it above 120? That will tell you if the standard JDM mod has been done to get rid of the JDM factory speed limitation (that is why you have the low speedo, JDM cars are limited). From the missing headlight covers I would assume it might have, since those usually don't leave the vehicle without nighttime driving of 100+.

When you talk about roughness when you "lift off from idle", you might mean "3K hesitation", where the engine seems rough (won't pull smoothly) from say from 2500-3500 RPM. That is a sign of standard grounding issues. Not at all unknown, and normal.

I would bet the coolant color issue is 11 year old coolant, since with those low miles it may have never been changed.
There is a good chance nothing else (maintenance wise) has been changed but oil and tires on that car. This also means that it probably has the original fuel filter, which is more than due for replacement, and a new one would help the fuel pressure back up to top levels.

Don't sweat the clutch, as long as it doesn't slip. Coming from light clutch cars it would seem heavy to you. I notice the same thing, since I have had my FD down for 2 months and have been driving my Ford Probe, where the clutch is lighter.

The fact that it still smokes after warming up is an issue. That compression test is needed. It might be some oil from the turbos. Next time, see if you can smell that pre shutdown smoke, is it sweet? If so then that might be coolant. The compression test should give you a better idea.

I think something was done to disable the AWS(Accelerated Warmup System), and that is causing your blipping. Is there a hose still connected at the back of the engine bay, going into the elbow? Look at the intercooler, follow the pipe on the right, it connects to a (OEM) plastic elbow. That elbow connects to the throttle body, a 2 inch wide metal piece. If there is no hose at the back of the elbow, just before it meets the throttle body, then the AWS was disabled. This is a good thing, since Mazda added the AWS to heat up the engine faster by running a higher RPM at startup.

pistole

Hi. Thanks for the replies.

I think that I will either have to have someone experienced look over this car or I will have to pass on it.

1. Consuming coolant
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I took a look at it again last evening after work and discovered that the engine is consuming its coolant. This was because I compared coolant levels since my last test with the car 2-3 days ago. Combined with the whitish smoke from the exhaust from cold , probably means that the coolant is going into the combustion and is being blown out the exhaust.

Not good.



2. Roughness From Idle
______________________

This is not the 3,000 rpm stumble.

I listened carefully today whilst revving the engine with the hood open by turning the throttle butterfly by hand. There is a very strange induction 'flapping-burping' sound when I throttle up from idle which coincides with the engine's stumbling/roughness. The noise is quite loud and eminates from the exhaust/turbo area of the engine.

I do not know and do not have enough experience with this engine to determine whether it is a broken turbo hose (causing the 'burbling' sound) , broken exhaust (I don't think since I can't smell any exhaust gas in the engine bay) , broken induction pipe (Its the stock plastic one) or something (!) else.......

The sound is quite loud , very evident when you throttle up (coinciding with bad engine vibs) , goes away after you throttle up (the engine then stabilises) , after that , you can't hear anything else over the engine's roar.

I know that its very difficult to diagnose with the little info that I have supplied and I also get annoyed with people asking me sometimes , "My car makes a funny noise, what's wrong with it?".

But does anyone here have experienced this type of problem before to be able to offer an opinion ?

Even if I decide to pass up on this car , I will still be in the market for one and moreover , any engine faults can basically be reduced into a $ sign , ie , whether the dealer is willing to knock off a reasonable amount to justify me in risking it and taking up the car and finding out that I need to have work done to it.

I am a practical person , I certainly don't expect a high performance 11 year old car to be 'perfect'.

Thanks in advance for your views.

NB : I did not take the car past 100 mph ........... I ran out of road ............. and I noticed that the dealer that went out with me for the test was gripping the sides of the seat ever so tighter ..........

turbojeff

iTrader: (30)

My point exactly. Don't do a hose job unless your replacing the motor. Hoses DO NOT crack unless they are messed with. They don't crack on their own.

Fatman0203

My hoses never cracked, instead they bursted off. I think it had something to do with heat soak after shutting it off, the temps would rise. (this is with an aftermarket rad).