somethin not right w/FD
 

hey everyone, i just bought a 94 stock FD. theres no power after 6.5k rmp. the car has no top end. i bought it to a meet and a guy with a rx8 told me that it needs new seals, the next week a guy with a R1 told me that one of the twins might be goin out. i dont know who to listen to. i was just wonderin if all stock FDs are like this if not whats wrong with it. i live in houston, does anyone know a good shop around here that i could take her to? any help would be nice, thanks

Check your regional forum for advice about where to take it.

https://www.rx7club.com/south-rx-7-forum-34/

yea man sounds like your number 2 is dead. i had the same problem back when i was running the stock twins my boost was 10-8-5-2. the boost pattern should be 10-8-10 and hold all the way to redline. FD at high RPM move man so your turbo(s) sound pretty dead.

Take the car to either of these places:

http://www.rx7.com

http://www.gothamracing.com

your turbos aren't necessarily dead. the sequential control system is extremely complex consisting of a shit ton of vacuum lines, actuators, and solenoids. Any one of which can easily cause you to not get any boost from the secondary turbo at higher RPMs.

So start searching for info, there's a trouble shooting guide and vacuum diagrams, but I don't have links for them. Or a good reputable shop could help, but may be expensive.

mine had no power around that rpm rage too, and i thought the 2nd turbo was bad or something in that mess of the sequential turbo system, then i noticed a hole in the coupler from the Y pipe to the plastic crossover pipe, so i replaced it with a silicone coupling and then the car pulled harder then it had ever before, the full 12 pounds that i set my Boost controller from the transition all the way to upwards of 8k rpms.

+1 dude. unless your car is chucking out craploads of smoke or making funny noises its pro bably just a vac line split or a boost leak.

Do you have a boost gauge? if the car doesnt make more than 8lbs of boost on the primary, the secondary wont come on. You could have a boost leak preventing you from hitting 8lbs, which makes the secondary never come online.

This is bad because itll strian your primary as it tries to puff enough to maintain boost. Any whoosing sounds under full throttle?

1. get a boost gauge

2. take it from there.

I had a similar problem, turned out to be a stuck check valve in the rat's nest.

As said above, check the hoses and solenoids. I had a similar problem several years back, before I did my hose-replacement - it turned out that one of the hoses to the pressure chamber had popped off, effectively disabling the secondary turbo.

do you still have the stock precat or main cat? what are the mods and get a gague and get some numbers or noone will be able to help you

sure im right on it. um its 100% stock so no bost/air gagues. thanks for all the advice and help

Call up Brock or Alex over at Gotham Racing, tell them Rich sent you. (817) 788 8726, the shop is located in Fort Worth.

Seriously, if you have no records with the car, and aren't a DIY'er, I would bring it to the shops listed, and have them change out EVERY solenoid/actuator on/near the rat's nest and all vaccuum lines in order to establish a baseline.

Otherwise, be prepared to fix something, and have another fail, plus all the downtime, and PITA of pulling the UIM multiple times (in other words, lots of labor).

Also, be sure to test (pressure-test (aka, Disney test), not just electrical) EVERY NEW solenoid, because I've had two out of six that were bad straight from the factory.

:-) neil

I've got two words for you:
Preventative Maintenance.


Replace all the wear items on the car, it will prevent future problems, and you might solve your current problem if you're lucky. The fuel filter is often overlooked, because it's under the car. You can find how-to's for most of these in the "FAQs for 3rd Gen" sticky thread at the top of this forum.



01. Oil & Filter, $10-20. Get used to changing the oil in these cars, it's a good idea to do it every 2K miles or so due to blowby from the rotary/turbo configuration. Gasoline gets mixed into the oil, so it's better to change it more often.

02. Fuel filter, $20-50. Should be done every 15-20K miles. If this clogs or prevents flow, your motor can run lean and experience preignition/detonation. You would then need to rebuild the motor, and the price of a rebuild can exceed $5000 depending on where you live and how quickly you need it done.

03. Spark plugs, $15-80 depending on brand/type. It's a good idea to get new spark plug wires while you're at it, $50-75.

04. Coolant flush & refill, $15. Be sure to use ethylene-glycol coolant (green/yellow stuff, not orange), a 50/50 mix is best for the cold weather that most people are seeing during winter. More water will help transfer heat (best in summer), and more coolant will help prevent boilover & freezing (best for winter). Adjust the mixture based on the temperatures you're seeing. Bleed out all the excess air properly with a coolant funnel, such as this one made by Lisle: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/radiator-cap-funnel-eliminate-air-bubbles-342309/ . Note the difference in water temps (if you've already installed an accurate temp gauge).

05. New water pump & accessory belts: $30-50. You might not need these, if the old ones are still in good condition. Mine were really worn and cracked. If these fail, your water pump stops pumping coolant through the motor; you'll overheat and it's rebuild time.



These are minor modifications, but most people consider them necessary just like maintenance:
1. Water temp gauge , $50-150 USD depending on brand. Notice how water temps vary depending on speed and engine load. The car is considered cold until 180 F, try to stay out of boost until the car warms up. Water temps of 200-220 are thought to be safe, much higher than that and you're getting into dangerous territory.

2. Boost gauge, again $60-150+ depending on brand. Get a baseline measurement, to compare stock vs. future mods. Boost pattern in 3rd gear should be 10psi by 3500RPM, drop to 8psi around 4500RPM when the second turbo kicks in, then back up to 10psi quickly, and slightly tapering down near redline.

3. Downpipe , $150-300 depending on brand. Budget about $100 extra for all the gaskets, new studs & nuts you'll need, the DP-to-turbo-manifold gasket is pretty pricey.The OEM precat has been known to clog and fail as early as 60k miles. Replacing it with a downpipe might solve a high-RPM boost issue. It's a good idea to spend another $100 and get it ceramic coated (Jet-Hot, etc...), or buy some fiberglass wrap for $50. The car might take a little longer to warm up after installing a downpipe, but it's worth it because it removes a lot of heat from the engine bay. Be sure to keep an eye on your boost levels. Be warned also, the super-cheapo downpipes will be really really tough to install, with cutting/grinding sometimes required to make them fit correctly.

4. Air Seperation Tank (AST), $150-300 depending on brand. The factory one is plastic and can eventually wear out and crack from heat and pressure it sees. If it cracks, the loss of coolant and pressure can lead to catastrophic overheating / engine failure. An aluminum replacement can be bought from most rotary tuners, or you can buy a new OEM one from a dealer.



Good Luck,
-s-

Kudos to you for taking the time to type all of that stuff up Scott :djcelebra

I'll let you in on a secret: I typed most of that a couple of years ago. But since people seem to have the same problems, I just copy & paste my old posts sometimes, reorganizing and/or adding new material when necessary.

-s-

alright, thanks. i bought it with a slavage/rebuilt title. so theres no records of anythin.