Ryde _Or_Die

Well I fixed my ACV plate that was leaking and that fixed my idle problem. But I still get really bad hesitation under boost. Can not figure it out for the life of me. Any ideas? When I'm not in boost its not there.

Wankel7

Huh, I am assuming the pill in the vacuum line to the boost sensor has been mentioned?

James

importboi22

make sure all your intercooler pipe clamps are down very tight... it may not leak under vaccum but soon as a little boost builds it leaks...

Ryde _Or_Die

No idea about this. Can you explain further? I don't think I have a pill in that line. I have vac line coming off the UIM that goes to a Y. One side goes to my aftermarket boost gauge, the other goes to a T. One side of that goes to my boost sensor and the other to my BOV. All done myself, so theres no stock hoses. So I guess I don't have any pill.

Ryde _Or_Die

I've checked all of them a few times. Only thing relating is now my car floods alot. I am guessing maybe I need new primary injectors?

Ryde _Or_Die

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Ryde _Or_Die

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Ryde _Or_Die

Still got a terrible hesitation. I was sitting with my car idling and flooring it and couldnt get it past 5k, no matter what. At first it would stop at 4k, then i let off and hit it again and got it to 4.5k, then did it again and got it to 5k. Any ideas/things to check? Its an all-of-the-sudden thing.

GLHS

What condition are your spark plugs in?


Pull all of them and inspect them, besure that each plug is firing..or whats is important here is ...are the plug firing at higher rpm? something is off, its either lack of spark or lack of fuel...


How is your compression on the rotors?

DaleClark

iTrader: (55)

Few things -

- Are your secondary throttle plates gone, or disabled? If they don't open properly, you'll have trouble reaching redline and bigtime loss in power.

- What all mods are on the car right now? You could also be running very rich. When I had my FCON and a rewired Walbro fuel pump, I ran so rich the car would buck and stutter under boost. After I got an adjustable FPR and brought the fuel pressure under control, the power was back.

- Are your plugs and wires in good shape?

- What kind of BOV do you have?

- Have you tried pressure testing the system to find boost leaks?

Hope this helps,
Dale

DaleClark

iTrader: (55)

Oh, one other note - the pill is a small, black bullet-lookin' job in the vacuum line to the boost sensor. I don't know if it's related to your problem or not, but it might be worth getting. You can get them new from Mazda for cheap - call Mazdaformance up on that one. Just stuff it into the vacuum line before the boost sensor and it's done.

Dale

1FastT2

iTrader: (1)

Have you check your tubing from the AFM to the turbo to make sure it is free from cracks?

Ryde _Or_Die

Ok, here is what I am going to do. I am going to change my plugs and wires and see if it helps. That pill, is it really neccesary? What does it do? How can I pressure test the system for boost leaks? As far as compression, I don't actually know right now. Should be good though. All my mods are in my sig except I removed my acv, power steering, and air pump. I've tried messing with the s-afc and see if I could get any changes at all. Didn't get anything. Thanks for the help.

DaleClark

iTrader: (55)

I think the 720cc secondaries, along with the fuel pump, is just flat out getting you too rich. You really need to go to work with the Super-AFC. I would definitely start with a new set of plugs - with hi-po turbo cars, expect to change plugs every 5-10,000 miles. Get a good set of wires, like Magnecors or Taylors, if you haven't done that already.

For pressure testing the system, remove the turbo inlet duct and cap off the turbo somehow - you want to seal the system. With an air compressor regulated to about 15psi or so, inject air into the system and look/listen for air leaks. You'd be surprised what you'll find! I've found things like rubber vacuum caps that were cracking and had a pinhole leak, a pinhole leak in a weld, leaking BOV's, you name it. Some stuff might be minor, but a good pressure test is ALWAYS a good idea.

Considering that boost pill is cheap and easy to install, I'd get one coming just for the sake of covering that base. I don't think it's a contributor to your problem, but it's worth doing.

BTW, have you done anything with regards to the secondary throttle plates?

Dale

GLHS

That pill is really a " restrictor" It was mainly an after thought.. Its only purpose is to bring the boost on quicker. If you add 2 in line, it comes on even sooner..
Dodges have the exact same pill.

It should not matter if it is there or not. We have a T2 without it and we don't have any problems....


Is your fuel filter new? Is it clean?

Are the injectors good?

Have they been tested?

What fuel pressure are you getting boost conditions? You have to have atleast double the amount of Fuel pressure as opposed to cylinder pressure including boost. So you start with 14.7 which is outside pressure, then add what ever boost you are pushing, you must have 2 times that amount to push the fuel out of the injector.


My GLH-S had a faulty injector and acted excatly like your car does... wouldn't run hard, had problems boosting over 15 psi... almost exactly the same symptoms, except I roasted the pistons...

BlackRx7

dcfc3s....can you elaborate on this pressure testing....how did you cap off the turbo...did you just use the bov line to apply pressure to the system?

DaleClark

iTrader: (55)

Actually, this pill is in the vacuum line to the boost sensor - it doesn't affect spoolup. A pill in the *wastegate* line, like on the '89-91 stock turbos, does affect spoolup.

The pill is simply there to smooth fluctuations from the intake manifold so the boost sensor gets a smooth signal - that's it.

[/B]Close. Static fuel pressure is about 35-37 PSI of pressure. This is what you get with the fuel pump running at atmospheric pressure - no boost, no vacuum. The pressure should increase and decrease at a 1:1 ratio with boost. So, at 10psi of boost, you should be at 45-47 PSI of fuel pressure.

The idea of the 1:1 ratio is to maintain a constant pressure differential between the fuel rail and the intake manifold. If they were both at the same pressure, no fuel would squirt out, since it's not going from an area of high pressure to an area of low pressure.

Dale

DaleClark

iTrader: (55)

I originally got the idea from an old Option video. They took a heavy plastic bag, folded it over a few times, and clamped it on the turbo inlet. Then, they got a vacuum line and hooked up an air nozzle to it - the kind you use to "squirt" air to dust something off.

I've also seen people make them from a PVC cap of some kind, and put a nipple in the middle of the cap to attach the air source to. There's really not much finesse to it - just pressurize the system, and look/listen/feel for air leaks.

It doesn't really matter which hose you hook up to to pressurize the system. If you pick a source after the throttle plates, you may want to make sure the throttle is cracked open so the pressure goes all through the intake tract.

Dale

Ryde _Or_Die

Well I don't have anything done to my throttle plates, no TB mod or anything at all.

As for pressure testing the system. I don't have access to an air compressor so I guess I'll have my local rotary shop do it for me. Shouldn't cost but $35 I believe.

Well I believe my primary injectors may be bad. Would this explain all of this? Lack of boost, hesitation, etc?

Wankel7

Yes, that pill will cause nasty hessitation. I met a guy who had a 88AE. It had an engine installed two years before. Ever since then it hesitated bad on heavy throttle.

So I meet this guy and start poking around. Check his vacuum line going to his boost sensor. No pill. New line there...so that makes sense.

Went to Advance Auto and bought a plastic restrictor fitting. Installed it. For $2 I made a VERY happy RX-7 owner. He had soooo many mechanics trouble shoot this. And I fixed it for $2.

Check that restrictor pill. It is cheaper than plugs and wires

James

Ryde _Or_Die

If I went to the parts store, what exactly would I ask for? Keep in mind these people that work at these places around here are, uh...dumb!

bl|nk

have you tried to feather the pedal up into the higher rpms? If I floor my car it hits a wall and I smell raw fuel.. but if i feather the gas 40% on the S-AFC it'll climb and still be boosting a little. i have 4x720's on my setup I think i was pulling like 30% out above 4k.

Wankel7

I used to work at Advance auto parts. So lemme try to help you on this one.

Go to where the large spinny thing is that has the vacuum hose things on it. You will see the plastic fittings. Such as T fittings and all sorts of crap.

Sidenote - Go in there with your boost sensor vacuum line so you can get the right size restrictor

Ok, it will just be a plastic fitting you slide one hose on one side...and the other hose on the other side. Inside this plastic deal is a brass restrictor. IT is about one inch long. It should say Restrictor on the package.

The best way to see if you have that restrictor on your car is to take the hose off and blow in it. You will be able to tell.

James

Ryde _Or_Die

Well its weird. My car is not consistent at all. Like just now I was running it hard up and down my street. A few times it would hesitate, but not so badly. It would go real smooth until like 5k, then would get a boost of smoothness, then hesitate at like 6. Very weird. I tried adding more fuel and it didn't help, only hurt. I had it set at 0% everywhere. Now in a a few minutes after it cools off I will try to take alot of fuel out, see what happens. With my boost controller off I only hit like 4.3psi right now so I shouldn't lean out at all. Let me see what I can do. I have some techron stuff in right now which I am trying to run through my system.

Heres a question for ya. When this started happening was right after the connection for my fuel cut switch came off. We put it back together and this started happening. Could it have been that it wasn't connected very well before, and now I am running super rich since we connected back together real well? Only thing I could think of. Because now my car seems to flood every once in a while, which it never ever did before.

Ryde _Or_Die

Ok, I just bought some t-fittings from the same area so i should have no problem finding it. Thanks.