Guys i'm getting bashed on my prelude forum about making sure i dont spend 20k on an unreliable car etc...
but what is it about FD's that are so damn unreliable that the first thing everyone says is... **** that car is unreliable... u better have money to fix it..

i dont get it.. the car im buying has rebuilt engine with 1k miles (i know for a fact it was built tougher than stock cuz my mechanic built it and i personally have known the car for over 2 yrs)
and a lot of outer engine parts such as alternator and etc... replaced! so wtf is so unreliable on these cars??
i spent over 3k on my lude just fixing bullshit that breaks so i dont understand how this simple engine can be more expensive or as unreliable as my ludes has been.

i mean i know little things break here and there ... its a 93' im looking at...
but honestly is it gonna leave me stranded?

 

"Prelude people" should be taken with a grain of salt just because they are driving Preludes...

But on the FD, where to begin?

Off the top of my head, these are reasons I would never buy an FD:

-Complicated turbo system using about 70 vacuum lines that has a near 100% failure rate. The vacuum lines and solenoids get baked by engine bay heat and malfunction.

-Turbo life often well under 100K. Some sets seem to last a long time, some sets fail under 50K, but most seem to be dead by 100K.

-Cooling system overstressed from the factory. The horizontally mounted rad is not ideal for street use

-Early speed density EFI system that will run lean with only intake an exhaust mods

-Plastic (yes, plastic) intercooler pipes. Why Mazda went through all the trouble to design a sequential twin turbo system then used plastic pipes is beyond me.

-Difficult regular maintenance. Fuel filter is mounted above diff, have fun changing spark plugs, etc.

-Interior is sort of cheap

-AST

I am probably forgetting some stuff.

Now, all of this can be corrected and you will have a reliable and fun car. The bugs in the FD have been worked out by Mazda and enthusiasts. Most of the issues can be addressed with aftermarket parts and fixes found on this forum. But that's going to add to the cost of the car considerably.

 

Well FDs are such a mixed bag it's hard to generalize.

They are not reliable compared to less powerful, more practical, more easily serviced, more common, less complicated cars. Just about every car on the road is more reliable than an FD just based on those criteria. You cannot compare a Prelude to an FD for this reason.

An FD can be a PITA for several reasons:
- poor past maintenance
- some maintenance tasks can be difficult (fuel filter is a great example)
- many maintenance tasks to consider (fuel system, suspension pillow ***** and bushings, engine wiring, coolant hoses are more/less maintenance on an FD but not on more practical cars)
- the engine and turbos are roasting everything within the engine bay
- the turbo control system has many, many parts and is not reliable when the hoses and solenoids get roasted over the years. Worse still, it's sometimes very difficult to pinpoint the source of a failure in these parts.
- bolt-on mods can overboost and pop your engine if not done with some level of planning or understanding
- if you run lean under boost, the detonation is capable of blowing the engine apex seals. It is a much more severe outcome than you will get with piston engines or unboosted rotaries. So you have to always have your boost levels and AFRs under full control as you make performance improvements.

That said, most of these things can be managed. The key is to know what they are, what damage they can cause, and don't buy an FD that needs a lot of work without getting a fair price. There are FDs that sell for full price, run well, but might have a toasted wiring harness, solenoids, radiator and AST, vacuum lines, and coolant hoses. It's not that such a car should be avoided, but that you should know what to inspect before buying and what work needs done before you will depend on the car. It's a car that punishes the ignorant.

There is an underlying theme in everything I've written - heat. The engine bay runs really hot, and most of the weaknesses in the engine are directly related to the fact that this engine generates an intense amount of heat in a small engine block. In general, the approach has been to run a little rich to keep the combustion temps and EGTs down, and beef up the cooling mods. That means things like improved gauges, better cooling system, better intercooling, and replacing cooling hoses, wiring harnesses, and solenoids before they get weak and break. A modified FD can be built to run cooler than stock and therefore last longer. This state of the art for a streetable FD is/was that: keep temps down, tune very carefully (avoiding detonation and watching EGTs), and replace the parts that get roasted as it happens. FD owners developed a list of "reliability mods" that make a stock car as reliable as possible, but still it's no Honda w.r.t. reliability.

The only alternative was to go NA with a bigger engine (20B), rebuild your engine more, or transplant in a V8. All three are expensive and difficult.

The state of the art is changing. The latest auxiliary injection systems are now as tunable as fuel injection systems. They use specially designed injectors and electronics. Until that, AI was a bit coarse for street driving. But now FD owners are beginning to install AI systems and seeing these benefits:
- much lower intake temps, combustion chamber pressure (temps), EGTs
- much lower knock, basically eliminates detonation risk
- much cleaner engine internals due to the steam-cleaning action of the water, which means lower engine internal wear, better compression, etc
- the lower engine bay temperature significantly reduces the heat damage done to other components in the engine bay

In other words, AI may help save the FD. Not that there are many out there to be saved, and I don't expect the FDs reputation to change much, but the ones that are out there will be much better for it. I fully expect the reliability to get much better, and for a lot less money. If you add AI to a nearly stock car most of the other reliability mods become less important.

If money is a concern, don't get it. If you have a little money to spend (I spend about $1k/year and I hardly drive mine), and are willing to sort out stuff and invest in some reliability mods, go for it. With attention to the right things, it can be a reasonably reliable car.

 

pfffft. If you want unreliable x7 get an first gen with a carb. I even look at mine wrong and it will flood the engine. Not to mention impossible to start in the cold with a MANUAL choke. Any rotary car is going to be a pain in the ***, but that's part of the love.

 

thanks for the feeback guys, this really helps in my current search for an fd. i'm going to double check everything in terms of the AST and cooling. the car has multiple coolers (i think 2 oil coolers? i dunno) but i believe the AST has been replaced by an aluminum one because being the noob i am i couldnt tell what the aluminum cylinder i was looking at the other day in the engine was lol... so that has to be it... the radiator is aftermarket, its single turbo converted and the engine is WAY less crowded than the stock twins hence giving more space for heat to dissipate, he's always put 2stroke oil with every other gas change etc... i mean this guy KNOWS his cars... he has a long history of building reliable cars that i've personally seen so i hope this all is going to help me make my decision in buying the RX!!

 

Well it sounds like a car that will run a lot cooler than the stock setup. Depending on the size of the turbo and the boost that you run, it can be really reliable in fact. If you have a single turbo and keep the boost down in a high efficiency range for the turbo, it can run really well. Of course, most people with single turbos crank them up, and that's where you get into rebuilding the engine often.

Put AI on a car like that, get it well tuned, and you'll have a very reliable monster. Of course, that assumes that what's there is well sorted already.

 

Very odd that he premixed every other oil change. I can't see any benefit to doing this.

Two oil coolers could mean that it is a factory R1 model. In that case they are stock.

You probably should have mentioned that the car was highly modified in your original post. It sounds like the car has been modified properly so all the original replies are basically pointless.

 

they aren't pointless because i have to learn this car inside out from basically NO KNOWLEDGE of ANYTHING except for how the engine runs.

this car is comparable to my prelude in honda, it's a pretty high maintenance vehicle and will also reward you well for the time spent.
Did they have R1's in 93'? how else can i tell if it's an R1?

i drove it today btw and its just disgusting...

another QUICK question.... when at like 4k rpm the boost starts hitting pretty hard and u heard a sick sound that sounds like a propeller going off the wall fast like shaking... i guess bad way to explain it but he told me thats the wastegate that's open pointing down towards the floor (which i saw before) and if i want it to stop i can loop it to the exhaust but i'll lose like 30hp... can anyone shed some light on this? are there any video clips? ima youtube and see if i can find anything

 

That means it has an open wastegate. It's venting exhaust right at the ground.

For emissions reasons and to keep down noise, street cars have the wastegate direct the flow back into the exhaust.

Personally I'd never have an open wg on a street car. But that's just me.

 

I fail to see how an FD compares with a Prelude on and level. Honda has long been held as a maker of very reliable cars.

 

believe me.. i know the cars in in diff classes but believe it or not the prelude is a high maint honda... specially mine!! every little piece of maint down to o2 sensors, EGR port/plug clean, valve adjustment, EVERYTHING has been changed recently. the car cost me 7k to buy and over 3k in repairs in the past yr. if the rx costs me 2k ill be lucky.

 

I think any care compared to a prelude is likely to be rated unreliable. Mine is a good example. 260,000 mi on original engine and it still starts up immediately and burns no oil. Hard to believe. I do admit it is a bit boring to drive.

 

If the wastegate is plumbed properly into the downpipe, the loss will be minimal. It needs to come in at a shallow angle and make a gradual transition. If it comes in at a right angle then the disruption in flow is huge.

A slight power loss is more then a good tradeoff for eliminating the noise.

 

Absolutely Aaron



H

 

i guess ima leave the wastegate down to the floor.. it sounds kinda cool its very different.

 

guys here's another question... when i start the car up it does this 3 times EVERY TIME,
it starts up on the 1st or 2nd click (which is better than my lude!) and revs up, then down a little, up, down, up and down, then it stays up around 1k rpm or wherever the normal idle is...
my mechanic said its normal it does that every single time and so far hes right, after that the idle is gorgeous. whats up with that?

 

[QUOTE=Aaron Cake;8944136]"Prelude people" should be taken with a grain of salt just because they are driving Preludes... i am a 19 i own a prelude and an FD and while i agree that the FD is a pain in the *** i feel that any other rx7 is obsolete, my biggest problem with the fd is that 1 thing can break or malfunction and cause 10 more problems that you didnt have before. And take what an FC owner says with a grain of salt when speaking on behalf of an fd. Dont knock the prelude because its a reliable daily

 

The car should start, rev up a bit (I don't know the startup RPM for an FD) and then settle to a high idle that slowly decreases as the engine warms up. A wondering idle usually means a vacuum leak...

I'm not bashing Preludes, I'm making fun of what people do to them.

 

oh i know plenty of preludes with chrome wheels and riding high like a chevy but thats not my style lol and it destroys the look of the car. mine was done right though thats all i'm really concerned about.. and a lot of my friends have cleannnn preludes that looks gorgeous. i love how the car looks. its actually really hard to get rid of my prelude.

well.. i dont think the problem with the RX is a vacuum leak of some sort... or else it would be consistant. it only bounces 3 times. its weird... but its consistent so im not worried about it.

 

have to agree... does it 3 times, every time, then settles. Vaccum leak would be al the time

 

The best thing ever to do to an rx7 is the ls1 conversion. It took mine from being scared to drive to my dd. I will now take the car anywhere and on road trips. It was very costly but worth it. I love Fd's so much and the way everyone responds to them. That alone is was worth it. If only it was more reliable I would of left it stock.

 

agreed

 

That's one person's opinion. There are others.

 

The only alternative was to go NA with a bigger engine (20B), rebuild your engine more, or transplant in a V8. All three are expensive and difficult.


You said it yourself about the v8 swap. Between my friends and I we have 6 ls1 fd's. They have been very reliable for all of us. I can see if someone didn't build it right it you could have bad results. I was just stating my good results to help out.

 

Then it ceases to be an RX7. Rotary power or nothing