Ok, being relatively new to the minor nuances of the rotary I may just be seeing normal stuff and worrying about it, but my new FD, compression tested recently good on all 6 faces, exhibits the following:

Cold:
Idle is lopey, 1500 rpm, never does the 3000 rpm fast warmup deal, supremely rich, like white smoke full of fuel and stinks.

Warm: runs perfect, idles good but LOW <like 500 rpm indicated> pops and crackles at idle <seems normal from what im reading> passes a dynometer style emission test easily, stalls ocassionally dropping back to idle and occasionally hard to restart when hot...I think some of this may be recall issues as my car is #253 ever by vin...<0200253>. Also appears to have the 3800 rpm hesitation...

From what I can tell the primary problem is the 3800 rpm hesitation deal, which i think is related to the whole grounding thing...any thoughts? I'm going to try and fix up the grounding this weekend to see if I can narrow the symptoms down.

 

Mike,

Did you just buy the car? Because the previous owner might have modded the Upper Intake Manifold and removed the AWS(Auto warmup sysytem) & the double butterflies. I recently swapped my UIM for one that had this done and my idle was suddenly very rough when cold and then once it's warmed up it idles smooth. Also, my car no longer revs to 3000 rpm at start up, thank god!

Just a thought.

John

 

Hm, I'll check it out, I just have to yank the intake elbow and look at it to check that out right? I did just buy the car, but all I can see done to it is the exhaust, which i THINK is a greddy SP, but that was kind of a guess, its definately a 3" though...and the car does move awful quick...also one thing i forgot, after its been driven like at highway speeds for a while it had an faint burning oil smell when you came to a stop, but its diminished alot since i got the car <maybe it was just a spill...?> Also the plugs are new cuz they were fouled when the mazda dealer did the compression check...the Honda dealer guy said he was told by the previous owner it ran a 12.7 in the quarter somewhere which seems awful fast for a virtually bone stock appearing FD...I'll have to do some more looking.

 

First off, congrats on the car. Welcome to the world (or hell) of owning an FD. It's truely a love/hate relationship with the cars.

The AWS (accelerated warm-up system) won't happen if you start the car in gear. Most people don't even notice it because of that reason.

As for the idle, it's a little low if it's at 500 rpms when the car is warmed up. The ideal idle is typically 750-800 rpms. However, if it's not bugging you or causing problems, don't worry about it.

The smoke and oil smell however could be a problem in the turbo area.

Since you just got the car, I would recommend getting the following things taken care of:

* Oil change
* Fuel filter changed
* Coolant system flushed

The spark plugs apparently have already been changed, so no need for that. Taking care of those items will at least let you know where you stand with the car as far as maintanence goes. Then any other small problems you have you can start diagnosing.

You could do those things yourself if you have the time and tools or just take it to a shop. Even most dealerships can perform those tasks without tearing anything up.

Good luck, and welcome to the club!

 

I'll tell you what I saw the other day...

Typically, I leave the hood open all night in my garage. The engine cools off to the point I would feel comfortable to close the hood after an hour, but with a secure garage, why go out there? So I typically start the car in the morning (daily driver) after I close the hood, but one morning, I went ahead and started it up with it open. Now, my car is quite stock, with only a DP. So when I start it up, it tries to shoot for 3K for warm up, but I tap the throttle, and it settles to 1750 or so, then gradually drops as the car gets warmer. Note that a 1K idle is acieved WELL BEFORE the engine temp is even to 160F. I will mention that the idle is typically VERY rough during this period, much more so when the parking lights are on. I'm pretty sure this has to do with the idle speed control valve (ISC) attempting to modulate the idle with respect to the input from the ECU's temp sensor (DIFFERENT from the dash temp sensor!!) and the electrical load sensor, which increases rpm to compensate for the higher load of the lights, or rear window defrost, or heater fan turned to 3 or 4. So a pretty rough idle during the 1.7K to 950 RPM is typical for a stock setup.

Now, what was interesting was that I looked at the DP as it was ideling high. BRIGHT ******* ORANGE!!! So bright that I could literally see STREAKS of hot gasses moving past the walls of the DP. OMFG!!

As it turns out, this is normal too (I hope!!). The ECU is set up to run the engine SUPER rich during this warm up period, mostly to heat up the pre-cats, which are of course now gone. I'm pretty sure that disableing the AWS system WILL NOT change this fuel mapping, and that this must be done using some sort of engine management system. By the time the engine is down to 950 RPMS or so, the glow disipates rapidly as the fuel mixture goes more towards stiochiometric. Also, of course, this NEVER happens on a warm engine.

So that's what I know, but this is a data point of one. Others with stock setups that retain the AWS AND the ECU should comment here. But I really think the AWS only controls idle speed (not fuel mixture) through both the ISC and thermo-wax plunger, and the double throttle system a is separate system, though not unrelated.

 

I'll have to do a fuel filter, all the others were done before i took the car <they did a coolant recall so the cooling system is fully redone> it had fresh oil too. On the AWS, its never been in gear when i started it, i always leave the car parked out of gear with the ebrake on unless im on a steep incline. The fuel filter could clear up some gremlins though, ive also been meaning to do a DP to eliminate the problematic precat. Thanks for all the help so far.