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-   -   Did my motor go boom? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/did-my-motor-go-boom-660361/)

TwinJDMSnails 06-08-07 03:15 AM

Did my motor go boom?
 
Hey guys,

i was driving home, on the last street before my house, gave it a little bit of gas and maybe hit 8 PSI or so.
Heard a pop and i lost all power. Motor instantly only rev'd to 3 grand. Made it home, but now when i start the car, it shakes violently, revs up to about 1500 rpm.. and then dies after about 10 seconds. Boost gauge goes up to about -2/3 psi when it is running.. which it def didn't do when starting up before.

is my motor gone?
i searched and some of the guys said it may be the MAP sensor, or a blown charge pipe... will i be lucky with that.. or am i looking at a rebuild now?
i miss the 7 already :(

Ottoman 06-08-07 05:35 AM

don't think you coulda broke it that easy...

easiest way is to pull a front and rear spark plug out disable egi

and the listen for even puffs while cranking

Mahjik 06-08-07 08:54 AM

What's your vacuum at idle (for those 10 seconds)?

Have you tried to pull the ECU codes?

A map sensor problem will cause the car to run badly, but it will run.

Sprockett 06-08-07 09:02 AM

That definitely sounds like a bad engine. Get your compression checked and pull any codes to see if it might be a sensor. Check the vacuum line going to the map.

Busted7 06-08-07 09:20 AM

Could even be a hole in the ic pipe.

Mahjik 06-08-07 09:24 AM


Originally Posted by Busted7 (Post 7022635)
Could even be a hole in the ic pipe.

That wouldn't cause the car to stumble and die.

TwinJDMSnails 06-08-07 11:11 AM

so you guys think it might be ok?

Mahjik 06-08-07 11:14 AM


Originally Posted by TwinJDMSnails (Post 7022993)
so you guys think it might be ok?

If the engine is shaking violently at idle (i.e. looks like a one of those paint shaker machines), then NO it's not ok.

Sprockett 06-08-07 11:21 AM

Is the needle on your boost gauge moving at all at idle? If so, this is a good sign your motor is done for.

TwinJDMSnails 06-08-07 11:48 AM


Originally Posted by Sprockett (Post 7023029)
Is the needle on your boost gauge moving at all at idle? If so, this is a good sign your motor is done for.

goes from its normal -15/20 psi to -2/3psi

TwinJDMSnails 06-08-07 11:48 AM


Originally Posted by Mahjik (Post 7023006)
If the engine is shaking violently at idle (i.e. looks like a one of those paint shaker machines), then NO it's not ok.

it does : (

rynberg 06-08-07 11:52 AM

It's a goner. You can do a compression check to be sure, but you should prepare for it.

TwinJDMSnails 06-08-07 12:07 PM

i figured its gone :(
crap.. back to the civic daily driver :S

rexhvn 06-08-07 11:59 PM

Is there a possibility of it just not getting spark? Causing the engine is shake..? Compression test is a good idea.

CantGoStraight 06-09-07 11:58 AM


Originally Posted by TwinJDMSnails (Post 7022993)
so you guys think it might be ok?

Based on what you've told us we'd have no better idea if it's gone than you would without a compression check. Just for future search's if you think something is a miss with the engine "GET A COMPRESSION CHECK"

RX7Crazy_84 06-09-07 01:22 PM

get compression test done! wish you good luck

jkstill 06-09-07 05:46 PM

Have you checked to see if the hose blew off the MAP sensor?

That will definitely cause very rough running.

TwinJDMSnails 06-13-07 02:35 AM

it started today and was able to hole idle.. def didn't shake like a paint shaker.. but def wasn't normal
no black smoke... some unburnt fuel though.. but that could be from almost flooding when trying to start it last time.
the hose didn't come off on the map sensor side.. so it could be under the UIM. Ill have to take a look at it tomorrow after i get off work

you guys think it might be ok?
i am gonna try to get it to a shop asap to find out, just been to busy with work.
so i am kinda happy that it starts up and idles.. just rough and not like a paint shaker. when idling, it almost sounds like a hole in the exhaust.

TwinJDMSnails 06-13-07 03:01 AM

anyone have the link to the guide on how to remove the UIM? ive been looking for hte last half hour.. and i must be retarded. I just dont' wanna remove anything the wrong way on this thing and break something else lol

Sprockett 06-13-07 08:24 AM

For FKS sake GET A COMPRESSION TEST!

Mahjik 06-13-07 08:25 AM

The map sensor line doesn't go "under" the UIM, it hooks into the side of it. No need to remove the UIM to check that.

IMO, get a compression test done before removing anything. If the compression test comes out ok, then you can start removing stuff to troubleshoot. Just use a piston engine compression tester which will at least give you an idea of the health of the engine.

RX7Crazy_84 06-13-07 01:06 PM

take to RG their out in new westminster they work on alot of fds, on of the guys their use to work at forcefed!

Fsunoles06 06-13-07 07:33 PM


Originally Posted by Mahjik (Post 7038187)
The map sensor line doesn't go "under" the UIM, it hooks into the side of it. No need to remove the UIM to check that.

IMO, get a compression test done before removing anything. If the compression test comes out ok, then you can start removing stuff to troubleshoot. Just use a piston engine compression tester which will at least give you an idea of the health of the engine.

wouldn't a piston compression tester just hold the peak amount of PSI for one chamber? Would seem hard to get any type of reading if you ask me.

Mahjik 06-13-07 08:32 PM


Originally Posted by Fsunoles06 (Post 7040226)
wouldn't a piston compression tester just hold the peak amount of PSI for one chamber? Would seem hard to get any type of reading if you ask me.

You pull the valve out so it doesn't hold the peak value:

http://www.rotaryresurrection.com/3r...ion_check.html

TwinJDMSnails 06-13-07 09:09 PM

when i look at the map sensor, the vacuum hose that comes off the bottom goes to a check valve, and then the vacuum line connected to that goes undernieght the UIM. Where is that supposed to connect? Ill look when i get home at the shop manuals.

I will get a compression test done, its just hard to do when you work 9-5 each day.. and the shop that you deal with is 9-5 as well. Im gonna do my best to do it on the weekend.


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