Mazda Rotary Club

General => General Technical => Topic started by: Jovic82 on June 08, 2009, 09:16:12 PM

Title: engine got me a bit stumped!
Post by: Jovic82 on June 08, 2009, 09:16:12 PM
well im finally back on the rx7 adventure after being away for a little while! i knew the bug would get me hooked again sooner or later and I have now bought myself another 92 Type r to keep me tinkering.

Anyway,

The car is running extremely lumpy on idle and also when driving seems like it is hesitating badly all through the rev range. My initial thoughts were that one of the apex eals had gone. I have performed the compression test by removing the plugs and listening to the "chuffs" - surprisingly everything sounds spot on and all chuffs are strong and of the same noise. A compression test was done last year and the results were as follows

Front Rotor
6.1
6.6
6.4

Rear Rotor
6.1
6.6
6.1

Now i know these are not great results and vary slightly but i would expect to get a few miles out of this yet.

There are new plugs in it, ignition pack has been changed, checked the earths in the engine bay and reset the ecu - still no change.

Car wont even start now and dies following me doing the compression test! could it possibly be a vacuum / valve problem?

Im running out of ideas peeps and would appreciate any thoughts/ recommendations before i go down the removal rebuild route.

Cheers
Nick
Title: engine got me a bit stumped!
Post by: Jono FD3 on June 08, 2009, 09:48:45 PM
as for the compression.... don\'t worry, drive it till it dies!! that\'s what I\'m doing & mine is some how defying the laws of physics!! 2 years ago at rotorstock (3 years this year) I had a comp test done & mine was between 4.9 - 5.4 on both rotors & she is still geting driven on the same engine :) !! As for the hesitation.... what boos pressure is she generating & are there any odd needle movements (if you have a boost gauge)??

Jono
Title: engine got me a bit stumped!
Post by: Jovic82 on June 09, 2009, 05:01:48 AM
Hi Jono,

Blimey thats quite inpressive that you are still running on the same engine! I have absolutely no idea what the boost pressure is as i do not have an aftermarket boost gauge on the car and still can not get her to fire up. When turning over i can hear here tryin to catch but just dies straight away
Title: engine got me a bit stumped!
Post by: Jono FD3 on June 09, 2009, 01:29:37 PM
Fuel filter..... fuel pump possibly?? They both OK?!!

Jono
Title: engine got me a bit stumped!
Post by: Grizzly on June 09, 2009, 02:57:49 PM
Have you checked the Map sensor, Water temp sensor?

Do you have a PFC?
Title: engine got me a bit stumped!
Post by: michaelb on June 09, 2009, 03:37:43 PM
When I had the T2 ( I have an FD now ) I had identical problems and as Jono says check the fuel filter as that what was my problem â€" it was filthy and almost all blocked up.  They should be changed every 2 years..

Regards,
Michaelb
Title: engine got me a bit stumped!
Post by: Jovic82 on June 10, 2009, 05:31:09 PM
right guys i have checked the fuel pump and that is okay - priming when ignition turned on and strong smell of fuel when i turn it over so its definately getting in the engine. Fuel filter i assume is okay as this has not been a gradual thing but started fairly quickly.
is there any way to check apart from removing to see if it is okay?

 I also noticed that the earth braid running from the plenum to the bulkhead has melted the connector a bit. it is still connected though. Im thinking it could well be an earthing problem but would this be severe enough to prevent the engine actually starting?

cheers
Title: engine got me a bit stumped!
Post by: Jovic82 on June 12, 2009, 10:09:29 AM
Gonna have a go at sorting this tomorrow so any tips? Think the car is flooded aswell now as massive smell of fuel when turning over!
Title: engine got me a bit stumped!
Post by: Jono FD3 on June 12, 2009, 01:31:48 PM
whip the plugs out, take the fule pump relay out & turn her over for a few seconds, put the pluchs & relay back in & see if she goes!

Jono
Title: engine got me a bit stumped!
Post by: Jovic82 on June 13, 2009, 10:51:02 AM
Cheers Jono,

Is the fuel pump relay the one marked egi? If not probably explain why its flooded after doing the chuff test!
Title: engine got me a bit stumped!
Post by: Jovic82 on June 14, 2009, 10:03:47 PM
discovered this afternoon that when removed the plugs to de flood her that one of the plugs does not screw all the way in and will only tighten to leave it 1cm out from being all the way in. i think this could well be causing the problem! would this create such an issue as running rough and sounding like only firing on one rotor?

if the thread on the rotor housing has been nakered, is it possible to re-tap it in situ or is this an engine out job?

cheers
Title: engine got me a bit stumped!
Post by: ozzyvelcro on June 14, 2009, 10:22:59 PM
Mine had a cross threaded plug a couple of years back, I took it to reworx where they used an old plug with groves cut into the thread and gently rethreaded the hole with the engine still in place, it didnt seem to affect the running of the engine though.