ghost-rider

I've got a problem. I bought a roller a little while ago, but it had the motor, tranny and rear end, I guess that sort of defies the point of a roller lol, anyway, motor worked fine, was hunting for the right indle speed but I played around with the tps and the adjustment screws and ut worked almost perfect although idle was still a little high around 800-850 rpm. It was workng fine until today. I was installing greddy turbo timer, and started the car to test if it worked, car idled for maybe 10 min, started hunting when it warmed up, here comes the problem. I opened the hood, and was looking at it, thinking what could be the problem, then I see a flame ignited for a fraction of a second in the vacinity of turbos, I turned the car off, took off the intake, and the cross over pipe, looking for the problem, the Y-pipe had oil on it, (pic) I assume oil dripped on the dp or on the turbos and momentarily ignited. There was no big fire or anything, just a flash. I can't figure out where the oil is leaking from. Is it the turbos?Are the turbo seals gone? I don't think it's the motor. There is also no 'charge relieve valves', I have no idea why, the holes are plugged with what looks to be the little legs usually found on the bottoms of chairs.

Mods: Mild/street port, hks dp, cat-less mid pipe, rb cat back, hks dual intakes. Rat's nest has been changed.

ghost-rider

One more issue found. On the exhaust there is a hose going from the engine (I believe UIM) to the cat. I assume it's there for vacuum purposes, but I really know what it does or what it's for. Previous owner installed a cat-less mid pipe and left this 'hole' in the manifold unplugged, the hose is removed completely but there is no plug. Should I plug it? or would that cause some kind of problems? I believe it shouldn't be left open like it is now.

There doesn't seem to be any bov's on the car but it still makes noise like a bov when you rev it a little. Should I put the original bovs/charge relief valves on it, or just leave those plugged like they are now?(you can see both locations where bovs attach in the pic, both are plugged) Again would leaving them plugged cause any problems?

ghost-rider

Anyone...?

P.S. By houston, I was not reffering to anyone in specific, just to NASA stuff, "huston we have ingnition"... etc.

tt7hvn

iTrader: (5)

ok......in relation to the turbos leaking oil, by design the stock twins have a "natural" amount of blow by. it's when it becomes excessive that it's a problem. in your case, i think you might have a problem. also, with some of those mods that you have, you should be running an upgraded ECU. a DP, midpipe and catback will cause boost creep and you'll have no way to restrict it.

when you say your rats nest has been changed, what do you mean? has someone gone through your whole vacuum diagram and replaced everything from the hose to the check valves to the solenoids? you might want to a do a little more investigation on what has been done and test if you need to. it's hard for us to give advice if we don't know what going on.

there is a lot of useful information on this site. run some searches and you could seriously spend a lifetime absorping the RX-7 community. i hope i have been some help.

cewrx7r1

iTrader: (2)

First you need to download the FD manual (is listed on this forum) and TOTALY study section "F". That cap is NOT where the charge relief valve was, but where the original BOV was connected. The CRV is connnected to the rear half of the "Y" pipe. SO where is the BOV now?

The pipe coming from the back of the lower intake manifold supplied air to the stock cat.


Once again, download the manual and become FD literate.

ghost-rider

^^^sorry I just went with what was written on the valves. One is black, one is brown but both say "crv" on them. I'm not as interested in what is the correct name for them, instead I'm interested if there is any potential danger of running without them. I have no clue of where either of them is, this is how I've bought the car. I have a spare engine left and it has both valves on it. Btw, both plugs are visible in the pic. That pic was intended to show where I found some oil resedue. However when you rev the car, it makes a similar noise as a bov would, may be it's the waste gate making that noise, I don't think there is anything else on there that could make this kind of noise. The pipe that supplied air to the cat, should I plug it, or leave it as is?


tt7hvn-- sorry, what I meant was that almost all of the hoses in the rat's nest appear to be new. They're silicone blue hoses, with a couple of exceptions. I found two original hoses, that's it, everything else seems to be new. I also found two of the 'tubes' where the hoses used to attach, one going to bov, the other one going to the crv. One of these tubes has a little plug on it and one is left open, unplugged. My main concern is where is the oil coming from, it appears to be leaking from where the two pieces of the y-pipe join. Does it mean that I neeed to replace the turbos or have them rebuilt? I did look at what others have said and I couldn't find anything relevant. I came accross a post where someone had a problem with a cracked coupler from y-pipe to crossover pipe, I replaced them just in case, since the ones that were on there looked relatively worn.

P.S. thanks for suggestions.

dgeesaman

iTrader: (7)

Take off the pipe leading to the bottom of the intercooler. If there is a puddle (not just residue, but a puddle) of oil, your turbos are shot and need rebuilt.

As well, if the coupler above the y-pipe was free of leaks the oil should not be getting out there either. Just start taking apart near the leak and replace all the gaskets you come across.

Dave

Mahjik

iTrader: (1)

ghost-rider,

Can you take a picture of the whole engine bay and your IC piping?

ghost-rider

^^^sure, I'll post one by tonight, the intercooler is stock, as well as the piping. I'm planning on changing this toy as soon as I find one similar to the size of Greddy fmic. The one that I have lifts and feels like it's going to explode under about two pounds of boost (2psi) the hoses connecting the I/C and either cross pipe or compression pipe (i believe) expand to unbelievable size and looks like these hoses will rip the intercooler off it's mounting brackets.

Thanks Dave, I'll try to take off the pipes from the intercooler, and see what's there. It might have leaked from the coupler on the Y-pipe, resedue goes right up to it. When I took off the cross pipe, there was a little oil on the coupler, but I figured it was normal.

ghost-rider

Here are the pics of the engine bay with the i/c pipes...

ghost-rider

This is the oil from the bottom of the intercooler...does this constitute a problem? I assume there shouldn't be this much oil in the I/C...



^^^ It's in the bottom end tank of the intercooler



This is all that came out, there is still some oil inside but it doesn't run out anymore, I have to wipe it off.

ghost-rider

P.S. sorry for the big pics, I haven't yet figured out how to resize them.

dgeesaman

iTrader: (7)

That's too much oil.

When you go down the road, and boost, does it smoke out the tailpipe when you lift off the throttle?

Dave

ghost-rider

I can't drive it yet as I only bought it about 3 weeks ago, with no interior and some small dents on the body, I was getting her ready for some new paint.

When I start her, I can't walk into the garage for about 5 min with all the doors open, lots of smoke, but when it warms up a little it's fine, still smells a little but I figured it was due to cat-less exhaust system. It wasn't running for a whileas it had no ecu and I thought that smoke should eventually clear up when I start driving her. Btw, I don't know if it makes a difference but it's a 1994 car and I put a 1993 ecu in it. all the connectors fit fine, so I think they should be the same. When I try to rev her, almost everytime I let off the pedal there is a puff of smoke coming out. Once, I went close to 7k rpm and when I let off there was flame coming out of the exhaust, almost as bright as when you weld, with a loud pop (backfire). I did it again later on and the same thing happened. Flame throwing/backfiring is constant at higher rpms. Again I figured it was the cat less exhaust and what I've read on here, something to the extent of 'rotaries have a tendency to send unburned fuel/ oil into the exhaust', so I thought it was normal.

What could be causing this? Any ideas? I don't want to put another set of turbos on there and have to replace next month.

I took off the Y pipe and everything inside looks nice and clean with some oil resedue but it looks normal. The shaft play is normal in the turbos, bearings should be fine. I guess the seals are the problem?

I also have a 93 motor from another rx7, so I took off the intercooler from that one and there was still some oil in it, so I poured it out and it was about half as much oil as from the one in the pics above, is that normal.

BoostedTimmy

Looks like you have all the symptoms of blown twins. The flames and backfiring could be from a multitude of reasons but I doubt the twins throwing oil down a scolding hot metal exhaust pipe helps.

ghost-rider

I think I've read that the flames were normal on an 'open' exhaust. But the oil really worries me.

Is it worth it to go with a single turbo set up, since I'll probably have to replace the twins anyway. I was thinking of having it set to stock boost level for now as I don't have any upgrades to the fuel and ignition systems yet, as well as the ecu.

P.S. Is there something like an ecu piggy back? Apexi pfc eliminates the obd which I need in order to pass smog inspection. Is there something that lets you keep the on board diagnostic system? 'Smog people' plug their computer in to get the readings from the ecu. This will probably be a problem as I have to get this smog inspection thing once every year.

ghost-rider

Could the absence of bov and crv cause the turbos to fail? Or is it something more serious? Why would someone remove these valves? Is there a reason? Some benefit?

Mahjik

iTrader: (1)

The ABV (BOV) and CRV are there to relieve stress from the turbos. The CRV vents the secondary boost until its time for it to come online.; the ABV vents the access air when the throttle plates close.

It completely conceivable to run the car without them. However, they are there to help the turbos live a little longer. Unfortunately, there is no real direct answer to your question. No one can really tell you *for sure* that removing those valves are directly related to your current problems as there are several people (mostly outside the US) who do not run BOV's with turbos.

ghost-rider

I tried wiping the oil off of the Ypipe and I've put back the crossover pipe, started the car, it warmed up and started hunting again. By the time she warmed up, oil resedue started to apper on the Y-pipe again and it is leaking from the coupler that joins Y-pipe with cross over pipe.

Will there be any other signs, except for the oil, that the turbos are gone?

Mahjik

iTrader: (1)

If you are getting oil pooling in the piping just from the car idling, that's not a good thing and most likely the turbos are shot. You can usually find good used sets on the forum for $200-400.

dgeesaman

iTrader: (7)

I think you should be clear on the fact that a replacement set of lower mileage twins is around $500, and the mods/stuff for a single turbo setup is about 10x that.

Dave

gracer7-rx7

iTrader: (16)

Sparks/fire can also happen from a coolant leak. There are 2 coolant lines running to the turbos behind where the air pump is. They get real hot and eventually start leaking.

It sounds like you need some newer turbos, need to replace the 2 BOV things, replace the coolant lines in that area and new crush washers for the turbo oil lines.

idle might be hunting b/c of a vacuum issue or idle adjustment or you might need a 94 ECU. hard to say....

good luck.

ghost-rider

I'm pretty sure it's the oil leaking from under the coupler that joins cross over pipe and the Y-pipe, but I'll check the coolant and the oil lines tomorrow. Might as well fix everything that may cause a problem while half the engine bay is taken apart, so I won't have to do things twice.

Dave, I have a rough idea of what single turbo conversion will cost me. I have a set of what looks to be good turbos, so I could replace the ones that are shot with a good set. However my goal for this car is to hit 400hp mark. This is in the future though, may be within a year or so. I'm just wondering if I should buy a single kit and run it at stock boost for now and with time change the ecu, ignition, fuel system, etc. or just replace the shot turbos with good ones and call it a day, again for now, until I will be ready for the single conversion. I don't think stock twins will be able to handle 400hp and even if they could I would thing that they won't last long.