Z691

HI,
Need advice;
- my Rx just came out from a complete engine rebuilt - all internal engine parts oem ( Racing beat)
- the 6 fuel injectors were replaced by new
- the 4 oil injectors replaced
- the ignition coils oem C series installed
- the spark plugs replaced by new
- new radiator installed
- new thermostat installed
- uprated 2k starter installed

50 miles after rebuilt

current symptom:
- Car starts fine at cold but no start at hot.and sometimes no start at cold
- car starts if kick started by pushing
- car shuts off when stopped
- on idle engine runs good but when accelerator pressed and released it idles to engine stop
- no engine cut off when accelerating from slow to high speed - 180/190 kmph - up speed is smooth and engine runs as new
- when engine is heated up, half way on gauge, on shutting off the engine, the coolant leaks from the overflow tube
- doing real bad fuel mileage
- no oil leak or water leak

need your advice
cheers...!!!

ZiG

Who rebuilt it, and why did it need a rebuild?

dannobre

iTrader: (3)

Double check the fuel injector wiring. A common error is to hook up the sec 2 and P2 injectors switched.

other than that it sounds like compression.

Z691

Blew up water seal due to overheating. Prefered to get a total rebuild.
Injectors connected as per user manual. P1 and p2 checked ok
Changed the radiator cap. Turned our the old one was faulty. No pressure/ vapour coulant loss.
Tested the car 2day when back from wk. Starts perfect but no start when hot. Tried again 1 hour later. Same symptom.

Z691

Do we have compression issue after rebuild? How long does it last?
Its run only 50 miled since out.
No misfire. No lags on acceleration
Engine does not cut when driving. Its smooth

dannobre

iTrader: (3)

Drive it for 300-400 miles and give the seals a chance to bed in

OEM Mazda seals can take a bit longer to seal in.

Hopefully you didn't heat it up so bad it warped the housings...but from the sounds of things it just needs some driving

Keep the RPM's low for the first bit...

Z691

Thks... crossing fingers...
Got sme more bits nd pieces comming...
New zl01 maf.
New 2.5 kw n3r3 -18- 400 uprated starter .. mitshubishi
New ecsentric pulley... changing tomorrow
New moshimoto thermostat
New radiator shaft nd fans... main reason of engine heat up befire rebuild. It was Murphy's law that day.

Hope for the best now.

Whr i am, no experienced mechanics for rennys... have to do most by myself...


Cheers

Z691

just took this vid.
i floored the accelerated jst to avoid flooding.. at some point when trying to start when hot.

Z691

Changed the eccentric shaft pulley kit by a new one today. Received it this morning.
Bad news ... the main bolt was loose. I unscrewed it by bare hand. Now new one fixed tight. Garage mechanic seems professional now.
Amyways.
Symptoms
- hot start issue still thr
- let it run iddle for abt 1 hr
- when clutch depressed. Engine turns off. Vacuum leak ?


New step.
- just ordered new injector gromets.
Lost one of tht when i removed the injectors. Not sure if the garage mechanic replaced the lost one. Better change all 6

BigBadChris

iTrader: (4)

You did the rebuild yourself?

9krpmrx8

iTrader: (46)

Do it once, do it right.

dannobre

iTrader: (3)

Did you make sure the front stack was in the correct position before you torqued down the front bolt?

If the thrust bearings and bits shift it is really easy to fubar things up.

Check that you have some end play on the shaft...otherwise you may have pinched something when you toqued it down

Z691

I did not rebuilt the engine,did not have time... i wish i did it now.
new eccentric shaft pulley kit fitted properly, as per manual and online guides...no more oil leak from there.
engine starts perfectly from cold, i left it idle for about 2 hours yesterday.
present issue is that when heated up, and clutch depressed to change gear, it dies.

personal diagnostic;
1) vacuum leak
2) engine running too rich- new MAF sensor due shortly
3) primary fuel to air sensor on exhaust manifold either needs cleaning or change
4) issue with main clutch cylinder - got a new one, will change it soon. both master and slave.
5) injector grommets defective - just ordered new ones.

up to now, my personal view is that when on load and clutch engaged, too much fuel in the engine chokes it.

your view and advice are most welcome.

Reoze

Who did the rebuild?

RX8Soldier

iTrader: (24)

Neutral switch

Z691

rebuilt was done by a local garage, car was always serviced there. basically they were the reference on the island but now i doubt their competence. I'm From Mauritius.
they could not find the problem. i took the car back home.
up to now; i fixed
- the cooling system problem, thermostat and radiator cap faulty, these replaced.
-injector P1 & P2 wiring which they inverted on re-assembly
- ECC pulley kit which was loose
- hard start from cold, now starts on a click.

hot start still an issue and will check on the neutral switch tomorrow.

Z691

How does the neutral switch come in the equation?

- all gears can be shifted and car runs fine, have to do that without rmp going down, feet on the accelerator pedal to stop it from dropping rpm
- only issue is ;
- if clutch depressed when driving, rpm drops and engine shuts down when stopping
- if accelerator pedal is pressed when car is on neutral, rpm drop and chokes the engine.

if engine is started and left on its own, it runs hours without shutting off.. even if clutch is depressed.


lost right now....!!!

MikeTyson8MyKids

iTrader: (1)

You won't be so lost if you check compression. It's been mentioned a few times already. Hot start issues has a high probability of being low compression.

Z691

Umm... if it is a compression issue,
1- should the engine not stall at certain point when i hit hard on acceleration. I mean i just drove it on highway and the car accelerated smoothly to hit 200kmph. No power loss.
2- on idle i mean neutral...when accelerator depressed. If compression was the issue. Should the engine not stall at certain rmp?

9krpmrx8

iTrader: (46)

Not all the time, a low compression engine can drive seemingly normal, it will just make less power. The worse it gets, then the idling and stalling issues will arise if a seal just doesn't let go.

Hard start when hot indicates that it is a compression issue if it starts fine when cold.

Loki

iTrader: (1)

Hot start problems usually point to compression. One way to find out!

Z691

i guess have to wait till i get another 300-400 mileage completed before hitting the compression test.

engine just rebuilt, only 70 miles on the rebuilt completed.

cheers guys.... !!!
will keep posted on the outcomes....

9krpmrx8

iTrader: (46)

Delaying the inevitable.

strokercharged95gt

Hopefully its just the combo of the weak starter and low compression. When I first rebuilt my motor it took me hours to try and start the car with 53 psi on the front rotor and a starter with 100k miles. Compression came up pretty fast once I got the car running, went up to 90 psi within a few idling sessions. After a thousand or two miles, I am just under 100 psi on that rotor. I later added a new starter and the car starts up within 2 secs everytime.

If I were you I would pull the front driver tire, pull the fuel pump fuse, pull the 4 plugs, and use a simply compression tester to see what your max pressure is in each rotor. It should only takes 15-20 minutes and give you a good snapshot of whats going on in that motor....

Dave04

Go drive the car for a couple hundred miles and then get a compression check before you throw anymore money at it guessing.

More then likely though its a compression issue sadly, my 04 would start fine cold but once she was warmed up on a hot day I would have to let the car cool down for 15 minutes before it would restart.

Good luck, did this shop have any experience REBUILDING rotary engines or had they just worked on rx's before?