BrodieRX7

Hi, I need some advice. I bought my 1993 efini rx7 a year and a half ago and it ran perfect when i first got it! if you put your foot down it would just go! and then i started to nottice when your realy put the foot down and when the second turbo came in it would stutter for a split second and accelerate again and keep doing it. Its hard to explain, i have tried asking jimmys rx7 and loads of specialists but havent solved the problem yet. now its running allot worse, when you put your foot down and it hits about 5000rpm it just cuts out for a second and then goes again and cuts out and keeps doing it? But it idles and starts ok? I have got my mecanic to replase the secondery injectors, sparkplugs, most of the vaccume pipes, and the fuel filter at the back. It feels like its fuel but im not sure? my mods are a bigger stock mount intercooler/hks dump valve/hks induction filter kit/and straight through exhaust. I put all the mods on myself and i dont know if its them that is the problem or what? can eny 1 help!? I love rx7s! and wont my 1 running sweet again so i can thrash more imprezas!

93rexy7

my car did the exact same thing it ended being my clutch slipping, i dont know if that helps any but its something to look into to. GOOD LUCK hope it gets fixed.

another7driver

That sounds like a dangerous mod combination. Look into a standalone once your problem is resolved.

dgeesaman

iTrader: (7)

The mods are a problem. You are hitting fuel cut. You installed more mods than the car can handle with a stock ECU and boost control system. Fuel cut is saving your engine from damage, but it doesn't work all the time so you should address it before that unlucky day arrives and pops your engine.

You need to address two things to get your boost under control:
1) Install an adjustable boost controller. Manual boost controller or electronic boost controller is fine, just so you can dial it back down to 10psi.
2) Either port the wastegate or put a little more restriction in the exhaust by putting the stock cat back in. This may not be strictly necessary but with a straight thru exhaust and intake mods it's usually necessary to stop boost creep.

And if you don't have a boost gauge yet you need one pronto. Can't set the boost if you don't know where it is.

Dave

BrodieRX7

Thats the same as what jimmys rx7 told me, but they say i need to buy an apexi ecu, and set it up for my mods. so i mite buy one. But am going to get a boost gauge first! Thanks so much for the help, this club is the best!

BrodieRX7

So if i put the induction kit/ the straight through exhaust back to stock would it run right again? or is it programed into the ecu now? changing the intercooler and dump valve wouldnt make a difference would it? Cheers for the help!!!!!!!

NOPISTONS?

How many miles are on the car, was the old fuel filter dirty. If the filter was dirty check the prefilter on the bottom of the fuel pump, it can slow down the pumps volume. It's easy to get to through the a hole in the hatch. You need to know what your boost is though. If you buy a boost gauge get one that reads 20-25 PSI, the numbers are spread out and easier to read than a super cool 30+ gauge. When I suspect any fuel problem I tap in somewhere before the regulater and put a gauge under the wiper arm of the car and go open it up. It can have good pres. at idle and no volume when the inj. open. Any shop should have a kit for that. I also put a relay with battery power to my pump. Check to see if your pump cuts off before you spend any mony.

dgeesaman

iTrader: (7)

More mods on the stock boost control system means more boost. But it's not well controlled. It's prone to spiking and fuel cut and you can blow your engine. (Many have done this). Adding an ECU is a poor choice because that's not the root of the problem. If you're going to add the ECU (and you'll want one if you intend to mod and make more power), install a boost controller with it.

If spending the money on an ECU and tuning now is not reasonable, install a boost controller and boost gauge. You need these two things to have a chance at managing the mods you've installed.

Any piece of aftermarket exhaust (you have 3), intake, or intercooler will alter the resistance in the system and throw off the boost with a stock boost control system. The main cat is a really big one. The BOV does not affect this. You'd have to uninstall a couple of those mods to reach safe levels for a stock ECU and stock boost control. I would just install the boost controller now with a boost gauge, adjust for 10psi, and keep a sharp eye out for boost creep. If you get boost creep you'll have to either port the turbo wastegate or put the main cat back in. I happen to dislike straight pipes on street cars so I'd put in the main cat anyway, but that's your choice.

Dave

BrodieRX7

Theres a blitz gauge on ebay am thinking about,its 52mm and it reads up to 1.5 bar. Should i go for it?

dgeesaman

iTrader: (7)

That'll do fine. Just be sure you can read from 0 to 1 bar very well.

Dave

Rotarius

I had the same problem on my 93. Many people thought that the problem was overboosting and I was feeling the fuel cut off but my boost gauge told me different. I had bolt ons even a pettit ecu and even I learned and checked the vac diagram the problem persisted. During 3/4 to wot around 3k rpm plus the acceleration will stuter several times. Well one day after rechecking the fuel lines I noticed that the fuel return line was plugged with what looked like dark fine sand????!. After cleanning the problem was gone and the car ran like a bat out hell. Unfortunatly I totaled it

BrodieRX7

Before i get a boost controler im going to try and put the old air box back on the old stock intercooler and put the cat back in the exhaust just to make sure thats the problem. Boost gauge is on the way!!!

BrodieRX7

Just had the rx7 out a blast with evrything stock again and its still just cutting out at about 5000rpm. and if your going along in 5th, out of know where it just starts to stutter!? Am i ever going to get this problem solved?

NOPISTONS?

What is the fuel press when it stutters? How old are your plug wiers? Are your plugs black and sooty or wet, after the car has been driven and hot. It's probably somthing simple. Take a fuel line loose and let the gas spill through a paper towle and check for trash.

BrodieRX7

I dont have a fuel press gauge so i dont know. It mite be a good idea to try checking the fuel lines tho? where abouts is the fuel line located?

NOPISTONS?

They can be hard to find, if your car is mostly stock their is a lot in the way. They come in on the driver side and go under the pelnium. You can find some great pics if you go to the archives and search for aftermaket fuel rail install or injector install. You could pull your secondary injectors and check them for trash but you need to check your running press before you take the car apart.

BrodieRX7

Do i need to get a fuel press gauge? it cant be the secondery injectors because was told it might be them and i changed them but it made no differance?

dgeesaman

iTrader: (7)

I agree with nopistons, to check fuel pressure against the factory service manual values. I once had a bad grommet at the fuel pump that was causing it to lose pressure right where the fuel pump feeds into the fuel line in the tank.

What boost level are you seeing when it cuts out?

NOPISTONS?

You don't need to install a gauge in your car, thats almost a privalage to have. You can get a parts store unaversal kit for mechanics. You tap in somewhere before the regulater, I like to run the gauge out under the hood, put it under the wiper blade and drive it. You can have plenty of press, and it drop when the injectors open. And remember when the boost goes up the pump has to match that press. If you do this and loose press pull the pump out of the back and check the screen, you did change the inline filter right?

Bojmend

Were you able to fix this?

davey_boy_smith

In addition to checking fuel pressure, due to the age (and possibly mileage) of the car, you should consider replacing the fuel pump with a good aftermarket one (to support your mods) while checking for any fuel tank debris and potential in-tank leaks as suggested by dgeesaman. It's a relatively inexpensive improvement/safety/upgrade and would allow you to (at the very least) eliminate the possibility of fuel tank related causes.

Mdhwoods

lol, this thread goes back to 09.

misterstyx69

iTrader: (142)

yes..it Does.

This is why we ask..GUYS!...CHECK POSTING DATES BEFORE REPLYING!
This thread is 5 years old..the original poster has not been on Forum for THREE years.(check Member Profile.)
Honestly,do you think his priority is to pick up his laptop and answer the thread?Do you wonder if the Member that just posted his NEW thread and needs assistance is now pissed off that his question is not being addressed due to some OLD **** burying his NEW thread?

If the threads have dust on them,then let them be and just READ them.
If you Post a new thread, and a member can help, it will get answered.

Thanks Lads.

NOW,I am going to take a big rock and kill this thread!
This thread is CLOSED!