MazdaManiac

iTrader: (3)

Yes.

Any OBD scanned will read RPM during cranking.

You would like to see 300 RPM or higher. The original starter was rated at 250, but often produced only 175 RPM.

Mazurfer

Now that's a good data point that I really didn't know!
Should be useful in helping others debug issues.

MazdaManiac

iTrader: (3)

I wish mine cranked as fast as some others that also have the updated starter.
Mine struggles with 250 to 275 and gradually adds RPM until 300, where the car suddenly leaps into life.
On a "good" motor, that isn't an issue, but on a low-compression motor like my current unit, start RPM must be high when warm.

Now that there are side seals in the retail channel again, I'll rebuild this motor with proper clearances and it won't be an issue. But the starter we are saddled with - een the updated unit - is pretty crappy for a rotary motor.

yamahayzfr6

Many thanks for the info.... I take it OBD is the On-Board Diagnostic? sorry if thats a stupid question !!!

I have the car booked in for later today for a diagnostic check, so will see what the results are... I rang the main dealer earlier and asked if they could check the RPM of the starter... answer from the service manager... "don't know"!!!! "I will try and find out for when you bring it in tomorrow".... God help me !!!!!

Will update when I have more info.... or not, as the case may be....

krisad13

somebody mentioned to me the other day that he had a similar problem to ours with an MG he had. He discovered that because the starter motor was close to the manifold it was making it so hot it wasn't working properly. He put a barrier between them with a bit of tin foil to reflect the heat and that solved his problem.

I could be wrong but i'm sure the starter motor is pretty close to the exhaust so i'm wondering if i could try sticking something to the exhaust to try and insulate it a bit as a temporary measure till i can get a replacement starter, anyone got any suggestions of what i could use?

Another thing i've noticed is that if take it really easy when driving then when i come to start it again it seems a little easier.

muckwarrior

I'm also suffering from this problem. Last night drove for about 20 min, stopped for about 5-10 min and then it wouldn't start. Had to crank it 4 or 5 times for about 10 seconds before it finally caught. Tried giving it some throttle a couple of times but it didn't seem to make any difference whatsoever. Same thing happend about a month ago.

I'll be replacing the air filter, coil packs and leads this weekend in the hope that it fixes it. If not, will try plugs after that and then a new starter.

Is it possible to tell whether you've got the upgraded starter by looking at it? I don't have access to OBD, and don't want to shell out even more money for that if I can tell by just looking.

J8635621

iTrader: (10)

There is a difference in size and also part number. Try looking up the DIY thread for starter replacement. It has the information.

Jon316G

iTrader: (1)

https://www.rx8club.com/showthread.p...hlight=starter

muckwarrior

Perfect, thanks.

MazdaManiac

iTrader: (3)

Nope. You are wrong.

krisad13

oh well just a thought like i said in my earlier posts i'm no mechanic, last time i messed about under a car was with my XR3i about 15 yrs ago.

krisad13

ordered my new starter today hopefully will solve my problems

krisad13

My Starter arrived last week and got it all plumbed in on sat. Took it for a good run and then no problems starting. Took it out again sunday and again no problems starting. Took it out again last night and when i got home thought i'd test it by trying to start it again on my drive. And the same problem is there. Anyone got any suggestions of what i should try next? New plugs, leads? or should i just get rid?

yamahayzfr6

Apologies for the delay in updating..... Took the car in to the main dealer (50m) round trip.... When I arrived they said they couldn't carry out a diagnostics check, as they had broken the connector lead... (could they not have rang me !!!)

It would be 3 -5 days for the replacement.... So.... I shared a few of my thoughts with their "8" expert mechanic as to the possible causes of the problem... He had never come accross a warm start issue before, so not much help...

Anyway, had a thought on the way home... in the old day's (3.0 Ford Capri's - RS Escorts) if you had a compression problem, a tin of STP oil treatment sometimes helped.... So stopped off and purchased a tin of WYNN's (they had no STP)..... added it later that evening....

Since then, (8 day's ago) the car has started every time.... once it took three 5 second attempts, but apart from that it has started first time, every time...

Yeah, I know it's not a permenant fix but fingers crossed, it will continue for a time.... and I can always add a little more.... :-)

It's up for it's TAX/MOT soon, and I think it may be time to part company not long after... Sad after 6 years, but at least I can trade it in as a "starter" which it wasn't before....

At £6 a tin, it's worth a try if you have the warm start problem.....

uncleant

iTrader: (1)

im having the same problem it wouldnt start last thursday and had to get it towed home, no start friday even changed the plugs, saturday started right up. made an appointment with the dealer and brought it in yesterday, on the way there had to get gas turned on the car started rolling away and stalled, wouldnt start for 10 min. dealer called me today saying they had it in and out of the shop multiple times yesterday and today and it started for them each time and they tell me they dont know what it is and the only way to find out is if it doesnt start. i am going to call tomorrow and have them do a compression test. i know with my luck once i take it back and it started each time for them its not gunna start for me

burnell

what happens if u have low compession.....mine has always starts but it takes a second to start sometimes ...

Mazurfer

if truly only a second, then that's normal.

krisad13

I would like to know if low compression shows any other symptoms other than warm start trouble?

And also is my problem (if it is low compression) likely to get worse in time or stay the same?

bse50

Every engine wears so yes,compression will get lower during time. However running with an engine with low compression may lead to serious engine damage in the event that a seal breaks etc. Something to keep under control definitely to avoid serious housing and side plate damage. Then there's the higher risk of detonation\pinging if the seals don't seal well but that mostly happens with FI rotaries.
You may experience harsh idle and symptoms like this, and a loss of power.

krisad13

Fitted new spark plugs and leads yesterday. And unfortunately made no difference at all. Still having trouble starting when warm. One thing i noticed is when after new leads plug where fitted and while the engine was running i touched one of the leads (coil end) to make sure it was fitted securely and got one hell of a shock. I assume this isn't normal anyone got any ideas what this could be?

krisad13

Any ideas on how to keep it under control? Still have the same problem, currently trying to sell it (at a cut price) but had no interest so far. So now wondering if i can get a bit more life out the old girl.

RotoScooter

Same prob with my 2005 Shinka 37,500 miles. Weak starting, especially when warm, seems like the cranking speed is down.
Initially suspected the Interstate MTL-30 battery I was upgraded to, by the dealer a few years back. I don't think it is. I keep a battery tender on it now when it's not being driven. So the battery is always fully charged.

So today, I started it cold, slow crank, but maybe 2 revolutions it fired up. Brought it up to operating temp for maybe 15 minutes. Shut it down. Restart was slower cranking, maybe 8, or 9 revs to get it to fire. If there was low compression, I would assume the engine would crank over easier, and therefore faster. It seems like slower cranking when it's hot.

Are these engines designed to have higher compression when they are warm? It kind of seems that way.

The next thing I did, while it was still hot, was to hook up my 200 amp charger/starter assist. It cranked right over and fired on the 2nd rev.

So, not sure, what, if anything, I've proved here, but it definitely seems crank RPM related. I'm leaning toward the starter as well.
If it's the weak one, which it probably is, (cuz' I would have remembered the dealer swapping it out), and the compression increases when the engine is hot, it all makes perfect sense...

Anyone know if the compression increases when it's hot?
Maybe the starter just gets tired when it gets hot, at least at first, it seems to pick up rpm as it begins to fire. Also it seems to fire easier if I turn off the starter just before it fires while l'm cranking it. That leads me to believe the voltage is down, maybe the starter is drawing too much current.

Tomorrow I will check the starter part # with an inspection mirror.


RS

bse50

Hot\warm engines have lower compression

RotoScooter

Ok, so the starter is the original, weak one. That's getting changed.

Meanwhile, did some more experimenting. Added about 6 ounces of Marvel Mystery oil with about 3/4 tank of gas. Went to the gas station, shut it down. Guy behind me was pissed already, he'd never seen anyone mixing stuff with gasoline and pouring it in the tank, well FU, bud. Then tried to start it. Wow did he get mad, cuz it took maybe 20 seconds or so to finally get it fired up. So then, I'm thinking, ok it's a hot start condition, huh? Alright lets get it really hot, and see what happens then. We have some very steep hills around here at least 2 miles to the summit, so here we go!!! Never let it drop below 5k, mostly 7-9000, plenty of beeping all the way to the top, saw a couple flashes of CEL just as I came to the top, never again. Some very spirited driving to keep the temp up, then down hill a few hundred feet. Pull over (heading downhill just in case). Shut it down. Waited about a minute. Cranked it over. Guess what???

FIRED RIGHT UP, and it was HOT, HOT, HOT!!! Continued down the hill, cooling some, pulled over, same thing. Turned around at the bottom, headed back up and flogged the holy cr@p out of it going back to the summit again. Now I can smell the thing as it it's screaming in agony, but that's what it likes, right?
Turned around, headed down shut it off, waited a minute cranked, and fired right up. So...


Is it really a HOT START problem??? Or masquerading as one? Or, does it just like Marvel Mystery Oil?? And if the compression drops as the engine gets hotter, can these results be from using that oil in the gas?
Anyone else try any of this?
RS

RotoScooter

So it's been a few hours, and it's finally cooled down. Went to start, and it did, although I think it did better hot. took it out for about 15 minutes worth of speed limit driving around 4500-6000 RPM. Parked downhill. Shut it it off. Waited a minute or two. Fired it up. Seemed like it was taking a while to fire. I think it does better when the engine is really on fire after a really hard, high rpm run. Maybe on the next tank with no MM oil, there will be a change..


Sure wish someone else would try some of this so we could compare notes.
RS