88turbotime

Hey guys, the car in question is an 88 TII.

When I try to start the car, the engine either turns over really slow, or hardly at all. It sometimes fires right up, but thats pretty rare. It usually acts like a weak battery, but I put a brand new battery and a new starter in it today and it still doesn't work. The old starter (which was recently rebuilt) either turned over really slow or just clicked. The new one started the car twice (although slower than usual) but now it just strains. You can tell its getting power it just sounds like its binding or something.

I can push start the car no problem and it runs and idles fine. It does have a little bit of a hesitation while cruising every now and then, but I don't suspect that's related. I'm going to get a new TPS installed (mine is unplugged right now because its on its way out) and see if that helps it run better.

So what am a looking at here? I wonder if maybe the battery cables are bad and its not putting enough juice to the starter or maybe the coils are going bad? I don't know what the symptoms of bad coils are so i'm just taking a WAG.

Thanks guys.

KusImmak7

You should get a volt meter and check how much volts is getting to the starter.

calpatriot

Is the new battery fully charged? i.e. is the charging system keeping the battery up? You could have a shorted diode in the alternator bridge, and the output voltage would be low enough to not provide a full charge to the battery. In some conditions, the battery can actually be discharging through the shorted diode. Sears can do a full check of your charging system for $10. Look especially for the diode pattern check.

If the charging system checks out ok, I would be suspicious of an impending carbon lock (internal friction due to excessive carbon build up.) Is there any reason to believe that the car might be running rich? Have you checked for trouble codes, and done the monitor lamp/closed loop operation check?

need RX7

iTrader: (4)

It could be a battery drain. I had very similar symptoms for the longest time, until I traced a battery drain back to something in the 'room' fuse circuit. I pulled the 'room' fuse at that time (about 2 months ago) and it has fired up right away every time since then.

If you do have a battery drain, you'll have to figure out what's causing it and fix it. I just lucked out and discovered that my car doesn't even have most of the stuff that the 'room' fuse supplies power to, so I'm able to leave the fuse out most of the time.

88turbotime

I'm not sure if the battery is fully charged, I didn't get it checked. I did have the old battery and the alternator tested at O'Reiley's, and they said both checked good. The voltage on the S-AFC reads 14 when running and 12.3 or 12.4 when not running.

I am interested in this carbon lock theory... I did think to myself that it seemed like there was a lot of friction in the motor or something, but it runs pretty good once started. I do believe it has been running rich, though. Is there any way to check this without pulling the motor apart? I've heard great things about seafoam, should I try that?

It is sending a code, but I believe its the O2 sensor code which it always has done since the emissions were removed.

I am not familiar with this monitor lamp/closed loop operation check.

88turbotime

Battery drain sounds pretty plausible, too. This thing has had little electrical quirks for a while now, like the instrument lights don't come on right away when the headlights come on, and some times they flicker a little bit. Thanks for all the help guys, and keep the ideas coming!

calpatriot

Carbon lock is the buildup of internal carbon deposits such that the engine cannot turn. I know that it happens; it happened to my car, and the mechanic was quite familiar with it, which suggest it happens with some frequency. The exact cause and mechanism is not clear to me.

If you are running with no O2 sensor, it will be running rich all the time. I believe that increases the risk of a carbon lock, but no one has any hard evidence.
Not directly, at least not that I know of. If it were me, I would reinstall the O2 sensor and make sure it plays with the ECU, and see if the problem gets better.
I have no experience with that.

I would put it back in; it will not affect acceleration.

I am not familiar with this monitor lamp/closed loop operation check.[/QUOTE]
One led to check to see that the ECU is seeing the sensor and adjusting the mixture up and down around stoichiometric. See my posts on 'green lamp test'

88turbotime

Ok guys, I'm going to start checking on all the stuff you've said so far, and I've been reading up on this carbon buildup. First I'm going to just bite the bullet and get a new TPS. Having that thing unplugged makes my S-AFC read 0% throttle all the time, which has to mess with the tuning. Think that could be causing it to run rich and accumulate some carbon?

I bought some sensor-safe carb cleaner today that I'm thinking about putting in the engine to see if it dissolves some of the carbon and lets the engine turn more freely.
Or, should I just push start it and drive the **** out of it for a while? I admit that I'm probably guilty of not opening it up enough, but at this point I'm worried about too much friction at high RPMs if that is my problem.

Thoughts?

BASTARD

iTrader: (4)

your car needs a good battery, good battery cables, good starter and good connections between the starter and the battery

the engine needs to spin over at at least 250 rpm in order for the crank angle sensor to trigger a signal across the reluctor/pickup

If your getting 12+ volts at the battery then your battery is probably acceptable

check the battery connections... disconnect them, clean them and then reconnect them

if it still cranks slowly, then you probabably have a bad starter

no_luck

iTrader: (3)

would the crank angle sensor cause a slow start condition?

im having the same problem with my car except i relocated my battery
but i have 1000 cca red top. new starter 2 gauge wire all around. i donno wtf it could be..oh and btw when i hook up a jumper pack to the battery in the trunk boy does she turn fast.

op im sorry to thread jack but we have a semi or very similar problem didnt see the point on starting a new thread. hope you dont mind

calpatriot

IF your problem is internal carbon build-up, you need to increase the internal combustion temperatures above 450C for a time; it should burn off the carbon (450 is the lower limit NGK reports for self-cleaning of the plugs; below that they foul).

If you have no operting O2 sensor, the ECU will run the engine rich all the time. This will lower the combustion temps, especially at cruise, and potentially lead to fouled plugs and carbon deposits. Under hard acceleration you are probably getting above 450 and burning off some of the carbon, but once you return to cruise, with the rich mixture, the buildup is likely starting again. The best thing for keeping the internals clean is to raise the combustion temps at cruise (where you likely spend much more time than at full accel), so that it will burn off the carbon while you are driving. This requires an O2 sensor, and verification that the ECU is going into closed loop during cruise, and this should also eliminate your code 5 (O2 sensor).

None of this will degrade your full power operation; the ECU goes into open loop/rich there anyway. You might gain some power because the plugs and other internals will be staying cleaner.

My carbon lock occurred after an extended (5 hr) trip (cruise) during which I later determined the O2 sensor was not working (open loop, rich).

Since I have fixed the sensor problem, and verified closed loop operation, the problem has not recurred.

Your hesitation at cruise might be related. It could be friction from an imending carbon lock (not my first guess, but possible); or, it could be a misfire due to fouling of the spark plugs, or ?

If your rich mixture is causing carbon buildup, removing the carbon with any of the various cleaners is probably a good idea, but only a temporary fix. The problem will return if the rich mixture/low temp operations continue.

rotorface85

im having the same issue in my 12a. i called racingbeat today because thats the only number i have on my cell phone when i was at work because i couldnt figure it out for the past couple days. it cranks real slow when i try to start it. when i remove the spark plugs and crank it over it spins real fast therefore i thought my starter was bad. the guy from racing beat told me to check my connections going to the starter and to check the voltage because it sounds like its a voltage problem. so i will do this tonight and if it works i will post again tommorow. i suggest you all do the same if you are having any problems like the ones above.

rotorface85

well i checked the voltage to the starter and its the same as the voltage at my battery 12.6V therefore its not the starter wire. i am going to try to ground the starter better and see if that works. i also bought a jump box today at a liquidation sale and it still doesnt change anything. i am starting to think i have a short somewhere. almost ready to rip my dash out for the 5th time and re do all the wiring to the engine and everywhere else. ps i bought a new starter and installed it just to make sure it wasnt the starter and it still does the same thing so i returned the junky autolite starter and re installed my mazda one.

rotorface85

well as a followup for all you rotor heads it turns out that i had a bad ground going to my starter (should have checked all the easy stuff first) i put a 4 guage ground directly on the starter and now it cranks fast again. i guess i should have thought of this before because of the thick coats of paint i put on the engine and starter and everything else when i had torn it out to paint under the hood. now i cant get it started again because im guessing my timing is off. i removed the eccentric shaft pulley when i painted the engine and didnt take note of where the timing marks were at... oops so now i am looking for the correct allignment of the pulley in relation to the shaft itself. does anybody know this ? i guess il be doing some research for a little while here and try to figure it out. i know that i have to slide the distributor in with the marks lined up when the pulley is on the first timing mark but i dont know if i have the pulley off by 90 degrees or 180 or 270 so i will figure it out soon.
anyone else having this problem do all the simple things first and dont waste 5 days like i did.

calpatriot

I have not tried the procedure, but I understand you can establish a new TDC position by taking the two plugs out of the holes in the #2 housing. TDC occurs when the apex of the rear rotor is halfway between being centered in the leading and trailing holes.

rotorface85

well i think i have it timed right now. but im still having issues starting it. i think it might be time for some new coils? i tested the ohm load of the coils and the leading coil is reading 1.5 ohm and the rear is only 1.2 ohm do you think that maybe im not getting enough spark? i found a set of pertronic coils for pretty cheap through jegs and they are good to 8500 rpm and deliver 45000V i think that should be good enought for my stock ported engine. i know im getting fuel because about every 5 minuites i have to un flood the engine. its been a long week of headaches with this 12a and im not too happy about it. the engine will spin about 1000 rpm when i go to start it and will fire about 4-5 times trying to start as tons of smoke pours out of the exhaust.