fstrnyou

88 TII

It's an Atkins rebuilt engine with streetport and HD corner seal springs. My dad says I have some wires crossed somewhere but from what I can tell, that can't happen. Mazda seemed to have put some thought into not putting identically shaped connectors right next to each other.

When the throttle is held steady, there is a miss. But when I rev it, it revs smoothly and idles down smoothly and then misses again when I try to hold the throttle still. I've only ran the motor for about two 5-minute sessions. Was looking through factory service manual for possible causes for rough idle today and checked several electrical devices. There are no open vacuum ports but there is always a possibility for a leak somewhere. Most of the lines have been replaced. I couldn't find a matching size on some of the lines.

Stock intake, stock exhaust. However, the air pump is removed along and the ACV and egr is blocked off. Since the ACV and stuff has been removed, some of the electrical connectors are disconnected. All the metal tubing under the upper manifold has been removed to eliminate the now uneccesary vacuum lines. And I believe the last thing that I've messed with... the coolant line running into my throttle body has been removed/bypassed. So now I have to remove the thermo-wax dohickey so I don't have high idle for 20 minutes.

Is there anything you guys suggest I reinstall or check to fix this thing. I haven't been driving my FC since late April and I am so close to getting it back up and running. Ask me as many questions as you like.

Dvst8

iTrader: (6)

timing correct? adjust tps yet??

fstrnyou

When I was going through the checklist in the FSM, I noticed some corrosion on one of the connectors that hooks up to a valve on the back of the UIM. Now it idles smooth, revs smooth, ect. Now, after a few minutes of running at just over 1K rpms, white smoke is rising from the turbo area, and at the same time, copious amounts of white smoke comes from my exhaust. Is that common with rebuilds or is there something very wrong with the motor I got, such as a water seal leaking?

Please help me. I'd like to drive it soon.

Craig

---PS--- at about 1200rpms, the timing is slightly advanced. but here's the kicker, when i check the timing, the leading and trailing coil are the same. the timing marks on the pulley are at the same spot whether the timing light is on leading or trailing. WTF???

Fingers

If it helps, mine does that too I'm convinced it's a vacuum leak, because i fixed two small leaks, and it got considerably better.

Fingers

the above was in regards to the misfire issue btw.

i'm not sure about what's wrong with the smoking

Kuhrazy7

I also have a small miss at idle. Im thinking vac leaks or maybe need to go over my timing. Revs increase and decrease smoothly but at idle it seams like theres a slight miss.

Dvst8

iTrader: (6)

I would definitely check the TPS.

can you tell us which mark its pointing at only? the first mark or second?

dr0x

Sounds like they pinched a coolant seal when assembling the motor.

AE_Racer

iTrader: (1)

yep, prob cooling seal...happened to me on a fresh build too

fstrnyou

well, i think the exhaust smoke was due to my motor overheating. when i filled the radiator there wasn't any coolant making it's way into the block. i took the thermostat out and filled the block and radiator again and put my old thermostat in. seems to be ok now. small amounts of smoke still seem to be coming from the turbo area tho.

now i have another problem. after driving for a few minutes at 60-70 mph, the turbo is glowing red when i pull over to look at it. don't think that's normal...

RETed

In regards to your original question, the engine will idle "funny" after a fresh rebuild. I usually can't get the engine to idle nicely under 1,500RPM. After the initial 500 miles, it should be able to idle to stock specs no problem. I use Mazda stock 2-piece 2mm seals, and I don't have any issues with them. These rebuilds crank over easily after the frech rebuild motor is installed on the first try usually.

Smoking turbo is not a good sign - how long has the turbo been sitting around? Glowing turbo is not a good sign either - EGT gauge or AFR gauge available? The engine does "run rich" due to the fact that compression is still coming up - this means there is fuel blowing out the exhaust, which can explain the glowing turbo.


-Ted

5 point whoa

I know most turbos do glow sometimes, but after 30 mins, I've never heard that

fstrnyou

Well, the car has been sitting since late april of this year. I do infact have a Defi' A/F guage. I'll hook it up tomorrow and see what's up. I just have to remember which wires are which.

The engine seems to idle fine around 1k. however, after a few drives down the street, it is ever so slightly rougher, but acceptable.

PS--- is it possible my pre-cat may be clogged???
when I took my pre-cat off to begin with, there were several large chunks floating around in the bottom side. I broke them up and removed them before reinstalling it after the new engine was installed.

Also, I set the timing of the leading coil to the leading mark and went to check the trailing and the pointer is still on the leading mark.

Craig

hypntyz7

Man, this isnt like a rebuilt 350 that you pop in your old chevy truck, fire up and have it idle and then go raise hell. Rebuilt rotaries are at their weakest when first started, and often run worse then they did before they blew in the first place. Do NOT expect your engine to idle perfectly. Even new housing engines are low compression to begin with. Just set the idle up a bit to between 1000 and 1500, and drive the car as much as you can. You'll notice it is weak and not really responsive, but the more you drive the more it will come up.

RETed

Oh, that's not good. If chucks of the pre-cat was busted, punch out the entire pre-cat. Also, CAREFULLY inspect the main cat downstream - the failing pre-cat tends to clog the main cat, so it's a good chance the main cat is also bad. This would explain a glowing turbo!


Wrong trailing ignition firing is usually an indication the TPS needs adjustment.


-Ted

fstrnyou

Well, I removed the pre and main cats. there were a few small pieces of precat in there but other than that the main cat appeared to be fine. In the inlet of the main cat there is a plate. I guess to keep pre-cat pieces from slamming into the mesh of the main cat. I'm interested in the RB group buy, so maybe I can just get the turbo back and forget about it.

fstrnyou

Update, I gutted the precat and left the main cat alone a put it all back on. Since I was under the car, I went ahead and unhooked the wastegate actuator from the lever arm. So now my waste gate will open simply from the exhaust pressure. I figure...why wire it open when it wants to be open anyway.

Anyways, I'm still haveing a problem getting it started. This morning I tried to crank it and it wouldn't start. Took the plugs out and dried them off, took the EGI fuse out, and cranked themotor with the plugs still out. Put the plugs and fuse back in and it started but was missing. Revved it and the miss went away. Drove it around for a while and saw the turbo wasn't as red as it was yesterday. Thought I was in good shape so I went home and shut it off. Was gonna put my hood back on and decided to check to see if it would start back up. Nope. Wouldn't start. Why does if flood out everytime I try to start it up??? I just put those plugs in there two days ago, can they be fouled already?

Was thinking about sending my Injectors to RC Eng. to have them cleaned.

Craig

hypntyz7

I don't believe you're listening to what anyone is telling you.

Fresh rebuilds, regardless of who does them, are LOW COMPRESSION. They are weak as ****.

What causes lack of power in a rotary? ONe major thing is LOW COMPRESSION.

What about poor idle? Low compression.

Flooding? A ton of people think injectors are the culprit, and true they can cause flooding, but more often than not, flooding is a direct result of LOW COMPRESSION.

I FULLY EXPECT a fresh rebuild to flood, idle poorly, and lack power for the first 1000 miles. IF it does better than that, well, you know you have a very tight engine. I expect the thing to still be less than spec for 2000 miles. I have seen engines that were still building compression after 2500 miles.

Furthermore, your glowing turbo was partially due to the engine running really rich...compression affects how much of the fuel charge actually get's used, and so low compression = unburned fuel. Since the seals begin to seat immediately, the thing smooths out a lot in the first hour or 2, and runs less rich, but still rich. Thus your turbo quit glowing.

Again, idle it up, put a fuel cutoff switch on it, drive it as much as you can (easy driving) and it will get better on it's own. Not much use in fooling with idle settings, TPS settings, a/f ratios, boost control, or cleaning injectors right now, because none of it means jack until that compression comes up.

fstrnyou

The only problem is, when i get up in the morning to go to work, i don't want to have to go through the routine of unflooding it.

before you yell at me for that, tell me more about the fuel cutoff switch...well, nevermind, i'm sure there is a thread in here somewhere.

jreynish

iTrader: (2)

I would listen to the man...
he knows..
Besides my engine only iddled at 2000 when i first got her started! and i let it iddle for about 4.5 hourse like that.. let her cool down over night.. then started her in the morning then it would iddle at about 1500 comfortably... I have an s5 with stand alone. and mine even flooded just like hypntyz7 said because of low compression. heed his words!

hypntyz7

Im not yelling, it just seemed like me and others were repeating ourselves and not being heard.

Instructions for a flood switch are here (my page):

http://www.rotaryresurrection.com/flooding.html

RETed

Boy, I question these rebuilds.

I've went through 4 rebuilds in 3 weeks, and all are up and running.&nbsp ALL of them started on the first try, and they all restart with very little problems.&nbsp Half of them are using brand new Mazda OEM 2-piece apex seals - this would normally cause lower compression on start-up, but nothing bad so far.

I've got one more I gotta do (waiting for parts), and I expect that motor to fire up right after being built.

dan atkins doesn't want to answer me on a previous thread on stock versus other parts, and his rebuilds don't sound too healthy either.&nbsp How much did you pay for that engine?


-Ted

AE_Racer

iTrader: (1)

RETed, whats with the &nbsp after each period? just wondering

RETed

Sorry, it's a matter of habit. It just adds an extra space in between sentences after the "." - the new code shows the "&nbsp", and I type that automatically sometimes.

Remember when your typing teacher told you to use two spaces after the "." in a sentenace closing?



-Ted

AE_Racer

iTrader: (1)

nah, I didnt pay attention in typing class, because I knew the basics already