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-   -   Think my motors done.... (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/think-my-motors-done-411878/)

Brent 94 04-05-05 02:25 PM

Think my motors done....
 
When i was driving home from school today, i was braking to stop at a light and i noticed my car didn't feel right. When i looked down to check the gauges, i noticed that my A/F ratio was at 11.1 on my wideband and the motor was stumbling(sounded like it wanted to stall). So i tapped the gas a few times, thought maybe an injector was stuck open or something. This fixed the problem a little because the ratio went up to about 11.7-12.0 but the car was still stumbling so i put my foot on the gas to keep the RPMs up around 1.5k and the ratio was normal 13.7ish. This happened every time i stoppped (just my luck i was stuck behind a school bus). I started to get really worried so i called ray( the mechanic i have always took my car to. I described the problems that i was experiencing and he said that it sounded like a broken apex seal but he doesn't really know whats wrong unless he can take a look at it. So i've decided i'll drive the car up there next week sometime.

Does anyone think this could be a different problem aside from a blown seal? maybe like faulty injectors or something along those lines.

The problems i've been having before hand are that my idle bounces sometimes but sometimes it doesn't and also my A/F ratio changes at idle frequently, like it used to idle in the low 12's so i had ray change it and now it idles around 13.3 but sometimes the idle bounces from 12.7-13.1 and sometimes it idles at about 12.5. Another thing is that in the upper RPM's i get black smoke (unburnt fuel) which was a way to protect the engine from the overboost and leaning out. does anyone have any ideas? I am really worried because right now i don't know if i can afford a full rebuild.

NeedFD 04-05-05 02:43 PM

how many miles on that motor?
could be faulty fuel system.. when was the last time that youreplaced the fuel filter?
i know that my friends' car, when the apex seal went bad he couldn't keep the car running..

Brent 94 04-05-05 03:04 PM

Um, i'm not exactly sure, i had the motor rebuilt about 2 years ago and that was around 60-65,000 miles and now my car has 97,000 so i guess around 25-35,000 miles. I had the fuel filter replaced about 2-3 months ago. Or at least i told them to replace it and they charged me for it so i hope they did. I've heard of people driving a car with a chipped seal before so i dunno.

CourageOO7 04-05-05 03:29 PM

Are you noticing severe power loss? When a seal is badly broken you can basically hear that only 1 rotor is running right (especially at idle). It's like "pla blunk pla blunk pla blunk..." My boost gauge was showing floppy, inconsistent vacuum at idle, too. Don't boost if you have a broken seal! You can mess up your turbos if a piece of a seal gets through... When I broke my motor I could just tell because it sounded and acted just like everyone has described on here. Some people with minor breaks say that the problem remedies itself as rpm's increase. I think Rikki told me it was because, although a seal may be cracked, the problem is disguised by a false seal that forms due to the oil/fuel injected as rpm's increase? Someone help me out here...
From previous experience, Ray's an awesome mechanic! Hope the new place is thriving!

Snook 04-05-05 03:34 PM

yours doesn't sound like a problem with the engine. There are many things it could be. Just let the mechanic look it over. I see no reason for the engine to give you a problem unless you've changed something reasently.

DaleClark 04-05-05 04:23 PM

As always, don't assume a motor is blown until you do a compression test. It's easy to do and will give you a hard answer before you jump to conclusions.

Dale

Brent 94 04-05-05 05:10 PM

Thanks for all the advice, i just drove up to the gas station because i needed to get gas before i go back to school tonight for my night class. I went very easy on the car and it didn't act up at all. It seems to be running....rough though. Could my cat be clogged? there is a slight rattle from underneath the car. Also, when i'm sitting next to a car or a curb i can hear my injectors (tick-tick-tick-tick) but it has done this for a long time with no problems and i plan to replace them.

Thanks again for your replies!

Brent

zayrx7 04-05-05 06:20 PM

have you changed your spark plugs

NeedFD 04-05-05 09:21 PM

agreed, maintenance check up
-spark plugs
-spark plug wires
-is the throttle body clean?

maybe the catalyc is getting old?
or o2 sensor going bad?

i'd let a mechanic diagnose it, sometimes it's worth it to pay and not deal with replacing a billion parts only to find out it was only one thing.

DaleClark 04-05-05 10:13 PM

Don't do ANYTHING until you do a compression test. Period. You're just wasting money if the motor is bad on anything else. If the motor is good, that weight is off your shoulders, THEN it's time for a tune-up and tracking the problem down.

I've driven FC's with blown motors for LONG periods of time - a blown motor will typically run fairly well.

Do a search on compression testing. You just need a $30 compression tester from Autozone and about an hour to do the test. That will tell you what you need to know.

Dale

kevinbtz 04-06-05 12:05 AM

sounds like a chip off the ol apex seal.
let me gues, it still builds boost like normal, and high way driving is fine.


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