Turbo II - Rough idle, smoking, choking under accelleration.

[NJGreenBudd]

Okay.

First some background for anyone who hasn't already heard:

It's an '87 Turbo II with a fresh engine from Mazda with less than 600 mi on the engine. Everything is stock except the HKS intake, the Racing Beat downpipe and the straight exhaust into APEXi N1 Duals.

The idle is now relatively steady give or take 200 rpms, it is idling around 1250. It still sounds kinda rough though.

Secondly the smoking is definitly noticeablle. It doesn't really stink like burning oil or coolant, its a light colored white/blue smoke. It doesn't seem to smoke as bad when you rev it up but once its revs down it smokes again. The engine seems to be running okay though, it isn't shaking or stalling. My dad says it might be running rich.

Thirdly under moderately hard(spirited) accelleration it kind of misses or bogs down or something. It starts to pull quite nicely but then, right when rotarys start to really shine, it just has no power and misses. You can feel the car just lose power when it "misses".

I'm thinking these issues are all related. I'm guessing the TPS needs to be adjusted....but I really don't know. Its needs a new blow off valve but this wouldn't cause these symptoms right?

My major concern is the rough idle, the smoking and the power loss under hard accelleration.

Here is what has been replaced : all vacuum hoses, belts, lights, motor mounts, gaskets, lines, injectors, seals, plugs, wires, battery, alternator, brake master cylinder, clutch, p-plate, throw out and pilot bearings, rebuilt rear, Racing Beat downpipe, new 2 inch y pipe into APEXi N1 Duals, fuel filter, diamond cut headlights, o2 sensor, factory stereo, HKS intake, tires(less than 500 mi on them), brakes and wheel bearings.

There is also a "screaming" or screeching sound that comes from the read end when you give it gas while driving.

Please reply with any/all ideas, comments, suggestions, questions or ideas. Thanks alot guys. I'm gonna see what else I caqn find on the forum.

[black rocket]

First, where did you pick up the engine from? I know you said straight from Mazda. Any warranty on that engine?

Second, it sounds to me like seals, apex seals, i.e., though mileage does indicate it's fresh, however, seal just as easily be blown (your idle for example and possibly improperly rebuilt).

Is that 2mm seals or 3mm seals? Hope it's not 3mm as if in fact seals are blown your housing maybe severely damaged.

As to the noise from the rear end area...being rebuilt... hmmm, did you ck for proper level of gear oil? Pack your bearing?

That's my suggestion.

[NJGreenBudd]

Hi there,

First, I actaully just got the car yesterday. This is what I have receipts for:

The engine came from Malloy Hyundai-Mazda-Kia located in Woodbridge, Virginia in October It's part # F008-99-008R-48 REMAN, ENG. The engine was installed by John's Automotive in Aberdeen, Maryland on 11/6/04.

Yes, there is a 1 year or 10,000 mi warranty on the engine. That is in effect until next October I'm guessing.

Second, I really don't think that the apex seals are blown. Not only because this motor is fresh but because the car runs good, it doesn't idle way erratic or stall, it starts and runs, just idles higher than I think it should. I think she should be down around 750-800 rpm but she idles at around 1250. The motor doesn't exhibit the death shake, it actually revs very smooth and has excellant power and pick up until you give it alot of throttle.

The main problems are that the car idles high, it emits a lite white smoke from the tail pipes and loses power when you gun the motor during accelleration. I'm thinking either an EGI issue such as pressure sensor or leaky intake line or possibly a bad collant seal in the turbo.

I didn't persoanlly check the level of gear oil, I will do that though. I'm thinking the best thing to do would be maybe rebuild it again. I am not aware of exactly what was done to it during the last rebuild. I was told that it had the "pinion gears" replaced. How hard is is to rebuild a rear? I got the service manual so I think I'm gonna be doing some reading.

Please let me know what you guys are thinking. Anyone ever had similar problems with idle, smoking and loss of power during hard accelleartion??

[black rocket]

That's exactly what I had happened when I blown my apex seal. You can try to adjust your air/fuel.

I've done swapping of Jspec rebuilt with adjustments (of course), my idle is exactly at 750 all the time exception of during warm up.

And it is certain that vac lines are all intact without any of them gotten loose? What size of hose have you used to replace that?

Most recommend 3.5mm instead of 4mm as it seem to come loose. And I was recommend to use Hose Tech silicone hoses and I'm quite impressed with their products (I think they are way proud of their stuff considering what they are charging...hehe)

And don't go with them cheap silicone hoses as it only has 300 degree max temp compare to Hose Tech's 500 degree tolerance.

And, yes I thought of coolant seal...ck thru filler cap and see if you see little bubble rises as it is an indication of coolant leak. Or pressure test it. Either way.

Have you done compression test?

Also how does your oil look? smell of gas, gunky...etc. That tells you a lot.

Keep me informed!

[NJGreenBudd]

Ok.

No I am not sure that every vacuum line is good or even still in place. I will be checking that either today or tommarrow. I'm not aware of what size hoses were used to replace the old vac lines. I imagine they were replaced by OEM lines or similar.

I'm gonna check that coolant filler neck and see if I can spot any bubbles. Is thi supposed to be done with the car running/idling/boosting? Will this detect a bad coolant seal in the turbo?

I haven't done the compression as I just got the car home and found this issues. If it can't be resolved at home in 3-5 days I'm gonna drop it off at my mechanic and let him see what's going on.

I also haven't checked the oil but thats a good idea. I'll probably do an oil change tommarrow and see what it's like.

Thanks for all your input. I know I am a noonie on this forum and really do apppreciate the help.

[Canaduh]

Okay black rocket is right, you should check all your fluids, and if your coolant is getting low, top it off, and if it continues, its probably a coolant seal. A white smoke is usually coolant.
Also check your Throttle position sensor, If not, it sounds like a vacuum leak. I dunno what else to say, goodluck!
Oh, if you find something wrong wtih your engine, just phone the company you got it from, and throw your weight around, you probably won't have to pay anything, and as for your mechanic, i hope he knows rotaries, as many don't. =D

[NJGreenBudd]

I'll check the fluids tomarrow.
I am aware that white smoke in the exhaust is usually indicative of either coolant or water being present in the combustion chamber.

I'm also going to go over the TSP, the cranke angle sensor, the fuel pressure regulator, the mass air flow meter, the variable resistor and the BAC valve.

I am also replacing the old air bypass valve with a new blitz ss BOV. I have heard that if the bypass valve is stuck open it will cause the wrong fuel map to be selected and possibly cause the rough idle, lack of power under boost and the smoking due to either too much fuel or too mucg oil.

Thanks again. Keep the ideas, comments or questions coming.

[black rocket]

And this is another pointer...

Since you have no clue as to what type of gas was used you may even want to look into carbon removal process by either yourself or by the dealer.

[Canaduh]

Good point, and also, if its a wrong f/a ratio, it wouldn't/shouldn't cause a white smoke, if its burning oil, it will be blue exhaust, and you can smell it. That could cause the bogging im guessing though, too much fuel might cause bogging. Im not sure on that though.

EDIT: Will carbon build up make those symptoms?

[NJGreenBudd]

A little update:

Started her this morning and waited for the smoke to start, lo and behold no smoke or very very little if any at all. The idle is still kinda strange: its starts at about 1500 to 2000, then slowly starts to bounce its way down to around 1250. I know these have the cold start and I'm not actually too worried about the idle, however I do think its kinda starnge to idfle like this. If driven and placed in neutral it will idle around 750.

The engine seems to be running a bit smoother though it never ran really rough either.

I am gonna give this a try tomarrow again, we'll have to see how it goes, I guess if I still don't like the way it's running after checking the specs of the TPS and replacing the BOV and other checks, then I'll just take it down to my mechanic. I'm lucky in that this guy actually know rotaries.