Clogged Cat??

[Rx-7fetish]

Okay so im now a new proud owner of an 88 10th ann, it seems to run alright when sitting still but when driving it feels bogged out, it drove fine when the previous owner bought it, but it had a straight pipe. He added a cat and im assuming its not a high temp and possibly burnt up and clogged itself, he drove it for 9 months before it started acting up. He never was hard on it, he never so much as did a burn out. It starts up easy. Also the boost gauge is unhooked, i cant for the life of me find a diagram or picture of how or where it hooks up. Also correct please if im wrong, this is my first turbo, i swear i read somewhere that it wont run right if the gauge is unhooked.Ask any and all questions that would help to narrow down on the problem. No i have not drove it long or far enough to see if it overheats but i was told it did not. I can post pics so just let me know what to take pics of and ill do my best to get them up.

[vex]

Could you be a little more specific in your post please:

Originally Posted by Rx-7fetish

Okay so im now a new proud owner of an 88 10th ann, it seems to run alright when sitting still but when driving it feels bogged out, it drove fine when the previous owner bought it, but it had a straight pipe.

What RPM range does it seem to bod down in? Is it only noticeable after a specific RPM?

He added a cat and im assuming its not a high temp and possibly burnt up and clogged itself, he drove it for 9 months before it started acting up.

That may be a possibility, but if you have a picture of the cat we may be able to inform you of one way or another if it's stock or aftermarket. However I would more than likely just hollow it out and run it like that, unless of course you're attempting to pass emissions in which case, do you have an air pump to pump air into the cat?

He never was hard on it, he never so much as did a burn out. It starts up easy.

Which probably means there's an increase in carbon deposits in the motor. Remember: A redline a day keeps the carbon away.

Also the boost gauge is unhooked, i cant for the life of me find a diagram or picture of how or where it hooks up.

Check the FSM. There's a link to it both s4 and s5 in the rotor wiki linked in my sig.

Also correct please if im wrong, this is my first turbo, i swear i read somewhere that it wont run right if the gauge is unhooked.

I'm not so sure about that. Check to see if your MAP sensor is hooked up, if it's not then the problem is not the gauge but the sensor itself which is connected to the ECU. I would find it hard to believe that the stock setup would use a voltage reading from the MAP to the gauge and then run the possible risk of having a worse signal going to the ECU. So I highly doubt that is an accurate statement--Though I very well could be wrong in that assessment.

Ask any and all questions that would help to narrow down on the problem. No i have not drove it long or far enough to see if it overheats but i was told it did not. I can post pics so just let me know what to take pics of and ill do my best to get them up.

Honestly I'd do a full tune up. Change all fluids and inspect for wear on specific parts. Oil, Coolant, Seals, and lines. Maybe even replace all the vacuum hoses or at the very least inspect them. Consequently if you're not familiar with the car itself it helps tremendously to know what has been replaced on the car and what is not specifically on the car from a normal one. Beyond that welcome to the RCC.

[Rx-7fetish]

Originally Posted by vex

Could you be a little more specific in your post please:
What RPM range does it seem to bod down in? Is it only noticeable after a specific RPM?

Just in general as soon as it moves, i have a lightly modded na and it seems to accelerate about the same if not a little worse. Which leads me to believe the motor itself is fine. At about 6 grand its like i just flat out let off the gas. Its got a manual boost controler in it, i would like to find the diagram of where everything is so i can hook the gauge up and get a rough idea of what boost i running.

Originally Posted by vex

That may be a possibility, but if you have a picture of the cat we may be able to inform you of one way or another if it's stock or aftermarket. However I would more than likely just hollow it out and run it like that, unless of course you're attempting to pass emissions in which case, do you have an air pump to pump air into the cat?

Its for sure an aftermarket cat welded into the straight pipe about halway between the motor and the muffler, which is also aftermarket. Dont have to worry about emissions where i live, but all the emissions are still hooked up.

Originally Posted by vex

Which probably means there's an increase in carbon deposits in the motor. Remember: A redline a day keeps the carbon away.

Im going to run some water through it per rotary ressurections site directions to clean out some carbon.

Originally Posted by vex

Check the FSM. There's a link to it both s4 and s5 in the rotor wiki linked in my sig.

Much obliged, i have an fsm for an 86, which didnt have a turbo model that year lol.

Originally Posted by vex

I'm not so sure about that. Check to see if your MAP sensor is hooked up, if it's not then the problem is not the gauge but the sensor itself which is connected to the ECU. I would find it hard to believe that the stock setup would use a voltage reading from the MAP to the gauge and then run the possible risk of having a worse signal going to the ECU. So I highly doubt that is an accurate statement--Though I very well could be wrong in that assessment.

Well i have read a lot of stuff that turned out completely wrong so.......lol

Originally Posted by vex

Honestly I'd do a full tune up. Change all fluids and inspect for wear on specific parts. Oil, Coolant, Seals, and lines. Maybe even replace all the vacuum hoses or at the very least inspect them. Consequently if you're not familiar with the car itself it helps tremendously to know what has been replaced on the car and what is not specifically on the car from a normal one. Beyond that welcome to the RCC.

Been here for a little while just not real active lol, and yeah im in the process, it has a manual boost controller, turbo timer, what looks like a fcd zipped tied next to the pressure sensor, ill get a pic, and an electric fan, i want to take that out and go back to the stock clutch fan, its wired to stay on as soon as the key is on.

[vex]

Wait... Something's not making sense to me... Explain this:

Originally Posted by Rx-7fetish

Just in general as soon as it moves, i have a lightly modded na and it seems to accelerate about the same if not a little worse. Which leads me to believe the motor itself is fine. At about 6 grand its like i just flat out let off the gas. Its got a manual boost controler in it, i would like to find the diagram of where everything is so i can hook the gauge up and get a rough idea of what boost i running.

Huh?

Its for sure an aftermarket cat welded into the straight pipe about halway between the motor and the muffler, which is also aftermarket. Dont have to worry about emissions where i live, but all the emissions are still hooked up.

A picture is worth a thousand words, are you sure it's not a resonator. Half-way between is about the ideal location for a resonator.

Im going to run some water through it per rotary ressurections site directions to clean out some carbon.




Much obliged, i have an fsm for an 86, which didnt have a turbo model that year lol.



Well i have read a lot of stuff that turned out completely wrong so.......lol



Been here for a little while just not real active lol, and yeah im in the process, it has a manual boost controller, turbo timer, what looks like a fcd zipped tied next to the pressure sensor, ill get a pic, and an electric fan, i want to take that out and go back to the stock clutch fan, its wired to stay on as soon as the key is on.

Just get a thermostat. It will be easier/cheaper unless you have a shroud for the stock clutch fan.

[Rx-7fetish]

Originally Posted by vex

Wait... Something's not making sense to me... Explain this:
Huh?

I have a non turbo 86 rx7, its lightly modded, the 10th ann accelerates about the same if not a little worse, when i took the 10th ann down the road it ran like an N/A until about 6000 rpm at which speed it was like i just completely let off the gas, the other stuff is what is on the 10th ann. I have no idea if its pushing any boost at all as the gauge is not hooked up, more inspection under the hood reveals what i believe to be quite a few vaccuum leaks, so im sure thats not helping things at all.

I just find it weird that the previous owner before the guy i got it from put a manual boost controller in it but claims to have kept it at stock boost, and installed an fcd.

Originally Posted by vex

A picture is worth a thousand words, are you sure it's not a resonator. Half-way between is about the ideal location for a resonator.

I know its a cat, he told me so, he bought at and had it installed at a muffler shop. I have a RB presilencer, im going to replace the cat with that if it is clogged.

Originally Posted by vex

Just get a thermostat. It will be easier/cheaper unless you have a shroud for the stock clutch fan.

Yep, i have 3 more rx7's besides this one and the one im driving, im going to replace the t-stat anyways just to have everything good to go when i get it straight.

[Rx-7fetish]

Cat



Engine when i got it



As it sits now

[vex]

Originally Posted by Rx-7fetish

I have a non turbo 86 rx7, its lightly modded, the 10th ann accelerates about the same if not a little worse, when i took the 10th ann down the road it ran like an N/A until about 6000 rpm at which speed it was like i just completely let off the gas, the other stuff is what is on the 10th ann. I have no idea if its pushing any boost at all as the gauge is not hooked up, more inspection under the hood reveals what i believe to be quite a few vaccuum leaks, so im sure thats not helping things at all.

Okay, now I understand. Yeah, fix all the vac leaks, ensure that the sensor connections are hooked up and we'll go from there.

I just find it weird that the previous owner before the guy i got it from put a manual boost controller in it but claims to have kept it at stock boost, and installed an fcd.



I know its a cat, he told me so, he bought at and had it installed at a muffler shop. I have a RB presilencer, im going to replace the cat with that if it is clogged.

He also told you he never got on it. Just replace the Cat with the presilencer and call it a day.

Yep, i have 3 more rx7's besides this one and the one im driving, im going to replace the t-stat anyways just to have everything good to go when i get it straight.

Alright then. Just for clarification I was referring to installing an electric thermostat for the fan so it wouldn't kick on as soon as you turn on the key.

[vex]

Hmmm... weird.

Check the air by pass screw on the top of the throttle body (usually covered by a rubber piece). I still don't think an adjustment of that much would cause it to go up to 7k. Just for caution unhook the throttle cable. Let the butterfly valves just be controlled from inside the engine via your hand. This will automatically rule out the back end of things. Once that's done you may need to pull CEL's to see what codes it's throwing.

[Rx-7fetish]

Thanks this thing is becoming such a head ache

[vex]

Originally Posted by Rx-7fetish

Thanks this thing is becoming such a head ache

eh, it's just a trial of patience... And wrenches.

[Rx-7fetish]

It was throwing the theres an acorn under your intercooler holding your throttle body open code.............

[Boostmaniac]

Originally Posted by Rx-7fetish

It was throwing the theres an acorn under your intercooler holding your throttle body open code.............

LOL, I am still laughing about that.

Check it out, if it is pulling as strong as your NA till 6k, then you have some SERIOUS problems. There should be a HUGE difference starting at about 3k on how hard it pulls when the boost comes on. If you aren't feeling a power surge there at WOT, then you don't have any boost. Next, when the power cuts out, does it feel gradual or does it feel like you just stomped on the brakes. If it feels like you are braking hard for a second, you MAY be hitting fuel cut, which doesn't seem right if you aren't boosting, or you may be running way to rich because you have no boost.

Do this right now, literally as soon as you read this. Hop in your NA, go get the cheapest aftermarket boost gauge you can find, put it on your turbo and go for a spin. Take your vacuum reading at idle and put it in here, then see if it boosts at WOT, if it does, then watch and see what the gauge does at 6k. If you are boosting I expect your boost drops to 0. Also record what psi you boost if it does in fact boost. Put all the information in here and then we can proceed.

Also worth noting, the stock boost gauge is useless. Aftermarket in ANY situation here is the way to go. See what the beast is doing, then come back.

Also if you want to get crazy, disconnect your cat and run DP open for a run or two. That will cross out a few things on the to-do list.

[Rx-7fetish]

Got a gauge but have yet to hook it up, just got it. Im almost positive its boosting now, i replaced the alt, it was bad, and the fuel pump plug was not all the way together. Also changed oil and added more coolant, fixed a coolant leak and changed 02 sensor and plugs, thats all so far and it feels about 3 times better, i hauled ass down my driveway (its long) it pulled much harder now. Now the only problem is that it floods itself when i cut it off, and it sounds like it has an exhaust leak between the turbo and the engine, i found brand new un open turbo to manifold and manifold to engine gaskets in the spare tire well, along with brand new set of unidentified rear shocks. SOOOOO im doin pretty good. Ill get the gauge hooked up and get back to you tomorrow on all that, i have to get a shower and get to my public speaking class as of now, thanks for all the help guys

[vex]

Tune-Up's are awesome! Glad it all worked out.

[Rx-7fetish]

Class canceled, so i went to tinkering, im pulling 19 psi vacuum at idle and about 7 pounds boost tearing down my driveway. It still floods itself whenever i cut it off though, and it sounds like it has a bad exhaust leak between the turbo and engine, with the fcd and manual boost control, i think it should be pushing more boost but is losing pressure from the exhaust leak. It was running like crap, today i couldnt even get it to stay running, turns out that the hose clamp on the intake at the turbo was lose it was giving the car a funky reading for the afm, the numbers above are after i fixed that. Now i have rough idle, and flooding, its always had the rough idle so thats not a new issue. so the problems are going away as i tinker with you guys help. When i got it, it was so bad the owner flat out told me the engine was blown. That was just a busted heater core hose causing it to lose coolant and overheat. Im thinking the injectors are bad, if i pull the fuse and crank for a while then put it back, it starts.







So does any of that sound right or plausible???