Tafumi

I did a loose search for the issue I'm having. But an exact match to my problem isn't in the system quite yet. (From what I've scanned at least.)

Sorry for the title of the thread. I'm not really sure what to call it.

First and foremost, I am mechanically enclined, but I'm not great at it. I'm a computer technicain, not a mechanic. The bulk of my experience is having a mechanic tell me what is wrong, how to fix it, and then I go and do it. I have practically no troubleshooting ability on my own.

I bought the car a month ago. It had a bad fuel-like smell and idle troubles where the engine would cut out if you left it at idle for more than 5 seconds. I only drove it 7 miles since then and then stuffed it in my garage. Two weeks ago I started it up to assess it's behavior. I tried it again today to see how it might differ. Nothing has changed between the three times I've started the car.

1: Car vibrates like all hell. Not so much when you give her some gas. But when you let her idle, it's like an earthquake in the cabin. Eventually leading to the engine cutting out.

2: Really, REALLY bad fuel/exhaust smell coming from the exhaust. Nowhere else though.

3: When I started it up, this black liquid shot out of the exhaust (and continued to shoot out for about 4 or 5 seconds) and splattered against the wall. It has no substance. It's like water mixed with carbon. I'm slating that as condensation that built up in the exhaust that was kicking it's way out.

4: Some smoke came out this time. Not a whole lot. Just a faint trace. Mildy burned the eye's, but I was in the back half of the garage when I did it - right next to the exhaust. It stopped kicking out smoke about 30 seconds into the 'run.'

5: No fuel or exhaust smell coming from the engine cavity. No smell could be detected from within the car either during operation.

I called my father who is more mechanical than I, and he said she might just need a tune up. But these cars can be such a fickled thing.

Before I go and seek outside diagnosis, I figured I'd ask the guys that have way, way more knowledge on these cars than I do. Before I end up breaking something or hurting myself.

The car is as stock as stock can get aside the addition of an Autometer boost gauge that doesn't work worth a crap. I got a GReddy boost gauge that I'm going to be replacing it with once the corresponding temp gauge gets to my door.

Just want an expert opinion. It's like some of the spark plugs aren't working or something.

Side note: The previous owner treated the car like crap for 5 years of his ownership. No tune ups, no nothing. He can't even remember the last time he changed the oil (which I already did) flushed the radiator (which I also did) he didn't even remember the last time he washed the car. Or wiped down the interior.


I'm not driving the car as it's not my DD. But I'd like to get it to the point where I could drive it with confidence when that rare good day comes around.

Much appreciated,
T

gracer7-rx7

iTrader: (16)

that is a car i would not have bought...

almost sounds like you have a blown motor. start with a compression test.

turboIIrotary

iTrader: (9)

+1 on compression check

Oun

iTrader: (3)

when i put my test pipe on and drove around for a bit...then i'd come to a stop light and errthang would just rattle like a mother bitch! then i found out the pipe was rubbing against the brace that sits right below it. went to a muffler shop and had them move the hangers around for like 5 bucks and no more rattling. the exhaust stills smells worse than the inside of an *** tho. cant do much with that unless you put a cat back on.

JP's 93 fd

iTrader: (28)

Sound to me like a blown motor. I just recently started having those kind of problems or symptoms after pushing my car. Bad idle (vacuum was at 10-12) and really bad exhaust smell. I'm goin to get a compression test this Wed. but I think I blew it.

samad

iTrader: (1)

i have kind of the same prob.......nut i doubt is a blown engine...cuz the cars still fast as hell...just idles like a bitch though.

FDdragon

damnit, im having similar symptoms....except my car doesnt die. it mosly happens when i start it up (plus its cold here) but it also shakes a bit after its warmed up and i drive around. usually it stays nice around 700-750 but sometimes i can see the rpm's flickering a bit.

my car also shoots out from the exhaust. and im not having any driving issues and i dont drive it hard. i might step on it once in a while but usually not very often or for long distances. just enough to remind me of the power. i just recently installed a bov and i seem to notice these things a little more. im gonna try adjusting the bov and see if that helps any.

what other symptoms would come with a blown engine? I mean, is the blown engine pretty obvious?

DaleClark

iTrader: (55)

OK, before everyone gets all excited with the blown motor posts -

I'd first make sure the vacuum line to the MAP sensor hasn't come off. That would produce exactly the symptoms you're seeing. Pop the hood, back driver's side of the engine compartment right above the oil filter is a black box bolted to the firewall with an electrical plug going to it. It should have a vacuum line running to it with a black plastic filter in-line. REAL easy for that to get knocked loose.

If that's not it, I can help you out. I'm not too far from PCity and can do a house call . I'll PM ya here in a sec.

Dale

FD3Steve

wut about if it was running way to rich. Could be throwin unburnt fuel out the exhaust,and it would definatly have a hard idle. i unno

JP's 93 fd

iTrader: (28)

yeah, my car drives pretty good on the freeway. My primary is still hitting 10 psi but I don't want to go over 4500rpm to see how my secondary turbo is pushing. Don't want to damage more ****. also I did check if the map sensor vacuum line is connected and my pfc also is getting a reading on it

FD3S2005

iTrader: (11)

if its as stock as it can get, meaning no upgraded ecu or anything how could it be running rich.

Take dales offer to make him see the car, he knows what hes doing........ i think... lol jk hes a good guy

BigWillieStyles

sounds like just a tune to me.

The 13B virbrates a bit when warming up anyway. The black liquid it spits out of the exhaust is condensation due to long periods of lack of driving and the cold weather. The exhausts always smell bad, as long as it doesnt smell like coolant and blow clouds of smoke after the car has warmed up, then its unlikely to be a broken coolant seal.

The idle sounds like it needs to be lowered a bit, but the engine will idle higher than 1000 until it warms up, in which it should drop to around 750rpm. It could also be a number of minor things. I would give it a good service and oil change, making sure to change all filters and spark plugs. Also change the fuel if you suspect its not been driven in a while.

I wouldnt jump to conclusions, as there really isnt anything you have said that sounds like you have a blown engine.

ThoRx7

i have a issue with my car.. i could smell like coolant rubber hoses... because i had a problem with my coolant hose connected to my turbo... changed it and sudden i could smell the coolant + the rubber hose from the inside of my car... any clues?

Tafumi

Checked the MAP Sensor and it's connected properly. Assuming what I was looking at was the right part.

Bolted to the firewall right above the oil filter. Little black box that says "Mazda Boost Sensor" and has a vacuum line and an electrical plug on it.

The car's idle problems happen at all temperatures. It happens when you first start it, it happens when you've run it for an hour (as I've been told by the previous owner.) It happens if it's 32 degrees outside or 92 degrees. The behavior is 100% consistent each time.

gafu mazda

talk to Dale

JP's 93 fd

iTrader: (28)

I did a compression test and the front compression chambers are low. This is what I got.

Rotor #1
1= 8.0kg/cm2 Rpm 259
2= 4.8kg/cm2
3= 3.8kg/cm2

Rotor #2
1= 8.4kg/cm2 Rpm 261
2= 8.7kg/cm2
3= 8.5kg/cm2

Tafumi

I plan on doing a compression test late Friday or early Saturday. I just don't want to deal with trying to get down to the spark plugs right now.

That's one thing I miss about my Impreza. Really easy to get to the plugs.

FDdragon

this is what my rpms are doing when idling. you can see my rpms moving up and down a little bit. it is more noticeable at other times and you can feel and hear when it drops a little. (the noises you hear in the back ground are the seatbelt light and the steering pod mount is loose because i wanted to try to get a closer video....i used my phone he he)

i revved it a little to see how the rpms drop pretty low.

like i said, my rpms didnt move as much as they occasionally do but i dont know if this is normal. i also dont think the rpms should be dropping THAT low when i let go of the gas.

just trying to get some info on what might be the problem if there is one. thanks.

http://www.youtube.com/watch?v=Agkj1GpPYuY

Tafumi

Did a compression test with a Piston engine tester. However, I have no clue what data to really record off of it.

I tested each rotor three times just for the heck of it. The front rotor seemed fine when I opened up the testers valve. I got 3 steady pulses, each registering the same volume of air moved.

When I kept the valve shut and cranked it, it immediately jumped to 130 pounds per square inch (give or take a few pounds) and stayed there.

The rear rotor registered in at 125 (or so) pounds per square inch. It also got 3 stead pulses of equal pressure when I opened the valve and cranked it.

Both rotors, while the valve was open, registered about 125-130 p.psi.

I hooked up my GreDDy boost guage and the entire time the car was idle, it was registering between 15 and 18 hg

I didn't actually drive it. Just left it running for 20 minutes.

I did notice something though. Once the car warms up, it's pretty ok for the most part. It idles just fine until you put it in gear which boggles the heck out of me.

If you depress the clutch, the idle is fine. If you put it into any gear (while the clutch is still in) the engine will start dying. It will stay alive, but the RPM's will drop.

The horrible vibrations go away once the car warms up, unless you put the car in gear. I didn't put it in gear and then start driving it though. That's a test for tomorrow I suppose.

I'm changing the spark plugs while I'm down there. From the information I've gathered, they're remarkably old and have tens of thousands of miles on them. Changing the wires while I'm at it.

grimple1

iTrader: (1)

well you want the valve out... or depressed. You want to register the bounces. Front and rear rotor. Here's a link on a HOW to. Also make sure the car is warmed up before doing the comp test. a cold comp test is useless.

http://www.fd3s.net/compression_test.html


the pulses can be steady but what psi are they exactly? you want to be above the 80-85+ range on each bounce.

Tafumi

I followed the instructions you listed when I did my test.

I registered the bounces. There was no delay or break in the bounces. Steady bouncing over a prolonged period of time. Each one registered at about 80-85 as you stated. This was on both rotors.

When I closed the valve, it registered a solid 120-130 when I cranked the car for 5 seconds.


I changed the spark plugs out. Didn't do a whole lot of anything that I can identify. My boost gauge doesn't bounce between 15 and 18 inHg. Now it just sits at 19inHg and only budges when I start giving her gas.

spaceman_spiff

so the strong odor of fuel coming from my exhaust is normal? i was worried that maybe my car had a fuel leak somewhere, but it drives perfectly fine. i too have slight vibrations at idle and warm up, but nothing cabin-shaking like you described.

Tafumi

Actually, since I changed the spark plugs, the overpowering smell is pretty much gone. All I smell now is your standard exaust fumes coming out the rear. Maybe a bit worse than what one would expect, but I don't know what the car was like in good condition so I can't exactly compare.

It's not really cabin shaking persay. It's a low idle that makes the car shake. That kind of thing.

Going to try to explain this again for the sake of myself so I make sure I got everything I can think of explained:

Car starts fine each time. No problems or hesitation whatsoever. No matter what temperature the car is, or how far/long/hard it's driven, it will still happen.

Car idles just fine so long as I'm not doing anything. Depressing the brakes doesn't do anything to the idle. Depressing the clutch does nothing to the idle. Gas obviously does what it is that throttle bodies do. If I give her gas, she'll return to idle. She might dip a bit low on the way back down, but then spring right back to the 750-1k mark.

Now, if I put the car in gear, the engine goes absolutely apeshit. So far I've only tested what happens if I have the clutch disengaged and I put it in gear. I haven't exactly completed the 'put it in gear' process here. I plan on doing that tomorrow because tonight I got to re-install the steering wheel, gauge cluster, drivers seat, etc.

Now, occasionally she'll idle rough for no apparent reason. But it happens like clockwork, every time when I put it in gear. It doesn't matter what gear. Also, when I put the car in gear, the boost gauge drops from around19hg to 15hg and starts slapping back and fourth between the two numbers.

sbnrx7

iTrader: (4)

Tafumi,
My car had the EXACT same symtoms as yours just two months ago. Bad smell, rough idle, etc. After performing a compression check my rear rotor showed 90 psi max and only one "good" bump on the compression gauge(blown apex seal). However, it was pulling 20 inches of vacuum which is good. I guess I'm telling you this because a compression test is the best measure of health you can get while the engine is still in the car. I would not jump to the conclusion that your engine is blown because you do have some healthy compression numbers....even bumps and a good number on the strongest face (because you're using a piston compression tester). Get ready to become very familiar with wiring, sensors, etc. as you are going to really have to search for the problem....but the guys on this site are great and willing to help. I don't think your engine is blown but something is causing these symtoms. Good luck and check what the people here suggest.

DaleClark

iTrader: (55)

From the description of your compression test, that sounds like you have a good motor. I think you're in the clear there.

Idle going goofy when shifting into gear is most likely the clutch switch. Do some searching on that. It either needs to be fixed or replaced. If it's bad, the ECU goes pretty bonkers.

Again, let me know if you need some local help.

Dale