13b N/A, has been fine for 3 months since purchase, little bit of stumble at idle but runs strong. Have changed spark plugs since I didn't know when previous owner had. Used NGK proper plugs like in FAQ (BUR7EQ and BUR9EQ, trailing=top, leading=lower) . Made sure plug wires are on proper (per FSM).

Drove about 10 miles for errand, was just fine. On restart after 5 minutes, idle was rough and a heavy miss continued up at speed. The car would buck at all rpms if held steady and also if decelerating. Had to hold RPM's up at stoplight to keep from dying.

Came off freeway exit near home (another 10 miles) and all of a sudden it smoothed out and ran normal.

Only recent change was addition of K&N Filter in place of stock filter.

I have read through the FSM Fuel and Emissions section and am intending on testing components this weekend.

Looking for experiences (if any) of others if this has occurred and what was the solution(s)?

Also any and all opinions are welcomed.

Tnx Fred

 

TPS. Try cleaning out the connector for it and then measure the resistance of it to see if there are any spikes. I have some how to's for the turbo version, which is a tad different, but it will give you an idea of how. www.rx7turbo.com/howto.htm

 

Cool, I'll check it out!

Tnx Fred

 

I tested the TPS (disconnected) with an ohmmeter and it was a smooth transistion up and down. I made a test light and set the TPS to one light on. It was off according to the lights.

I started the car and it seemed ok. Drove down the block and it started missing again, but this time with a bunch of oil smoke when it misses. It smoked real bad one time before\, almost like something was stuck and then it cleared up and did not smoke anymore until now.

I used the test lamp to check for engine codes but nothing happens with just the switch key on (not running) whether you have the other connector jumpered or not. I followed the procedure I found on the web site. It called for hooking up on a 6 position green connector up near the battery using ABR, Dcc1, and Dcc2, then jumpering the smaller green 2 pin connector right next to the first.....no signals.

If I start the car Dcc1 stays on solid while running!. I also can hear the BAC clicking everytime it has a miss.

I'm really confused now, Did setting the TPS to the lights cause this and if so, how come it's smoking? I never have traced out the oil injection system but could it being off cause it to inject too much oil?

Any help very much appreciated.

Tnx Fred

 

I tested the TPS (disconnected) with an ohmmeter and it was a smooth transistion up and down. I made a test light and set the TPS to one light on. It was off according to the lights.

I started the car and it seemed ok. Drove down the block and it started missing again, but this time with a bunch of oil smoke when it misses. It smoked real bad one time before\, almost like something was stuck and then it cleared up and did not smoke anymore until now.

I used the test lamp to check for engine codes but nothing happens with just the switch key on (not running) whether you have the other connector jumpered or not. I followed the procedure I found on the web site. It called for hooking up on a 6 position green connector up near the battery using ABR, Dcc1, and Dcc2, then jumpering the smaller green 2 pin connector right next to the first.....no signals.

If I start the car Dcc1 stays on solid while running!. I also can hear the BAC clicking everytime it has a miss.

I'm really confused now, Did setting the TPS to the lights cause this and if so, how come it's smoking? I never have traced out the oil injection system but could it being off cause it to inject too much oil?

Any help very much appreciated.

Tnx Fred

 

Dadgum double post!.....Sorry

 

1) how did the TPS connector spades look when you had the plug apart? corroded?
2) if you can, rig up the ECU code LED lamps from the plug to the cabin, so you can see any codes real time, as they happen (you can leave the ABR, DCC 1&2 wiring in the plugs while running, but take the jumper out of the initial set coupler)
3) if you have it connected properly, DCC1 should not stay lit all the time- it should come on for 3 sec at startup, then go out (DCC2 should do this, also)
4) sorry to be pessimistic, but you could have blown a seal or oil control ring with the rough running & smoke

 

Appreciate the response.
1. I checked the condition of the connector, burnished them with an old points file and sprayed with contact cleaner.
2. I did exactly that and just got the solid Dcc1.
3. The lights come on for about 3 seconds, go out and then the Dcc1 comes on
4. I sure hope not!

Tnx Fred

 

does the DCC1 go off, after like 5 seconds, or does it just stay on all the time? you didn't do anything to fry the ECU, did ya? Also, make damn sure you got the spades in that plug in the right spots...

 

Pretty sure I didn't fry anything. Dcc1 comes on with Dcc2 at initial turnon of the key, goes off after 3 seconds then stays on solid as long as the engine is running right. When the miss occurs, the click I hear from the BAC corresponds with Dcc1 going out, then it comes back on. The light stays on solid as long as idle is normal. I would think if the leds come on for 3 seconds and then go out they are hooked up correctly.

The only question I have had on this whole thing is most of the writeups call for a single wire green connector be connected to ground to get the codes. I assume this puts the car in limp mode. My car has a green connector with 2 wires. I assumed (I know!) the two wires needed to be jumpered to each other since none of the procedures indicated a specific wire to be grounded.

 

This is really getting wierd. When I got home from work I started the car from cold, it runs fine. It is only after it starts to warm up (ie: temp needle starts up) the missing and the smoke starts. Also still had the test light still plugged in and it did the typical 3 secs on and then off and did not light up again!

What is there that can cause one to only smoke when hot? It sure sounds like there is a valve or switch that is malfunctioning.

We are talking clouds of smoke, BTW, lots and lots (ie:cannot see in the garage at all)

As always, any ideas appreciated! Fred

 

Fred, check your OMP rod. If it's sticky or even worse, stuck, there's your problem. Mine was stuck open, so the car would run fine for a few minutes until revved, and then it would die due to too much oil. Installed new FC OMP and it runs better now. Gave me back some top end power too, strangely enough.

Zac

 

****ing forum. This is officially my first double (yes I know there's 4) post.

 

...

 

...

 

that sounds good...BTW, when you jumper the plug, you are grounding pin 1J of the ECU, that's why everyone says to "ground the plug"

 

That maybe it. I waiting for the car to cool down to stick my arm down there and check it. I'm gonna owe you guys bigtime!

Tnx Fred

 

OK, it cooled down enough for me to get my arm down there. I can move the rod up and down, both by hand and using the lever that the TPS is conected to. The drawing makes it look like there are two cams down there but I only feel the piece that the rod connects too. Am I missing something? I may get under it this weekend and see if I can get a better vantage to look.

I really appreciate everyones help!

Tnx Fred

 

I am having the same problem...I replaced the ecu and it went away.. then 6 hours later that ecu went to crap.. if you figure it out lemme know.....

trevor

 

Is it possible for the OMP rod to move and the OMP still be stuck open?

I got the car up in the air and warmed her up and the rod moves just fine but I still can't get an angle to observe if the shaft going in is moving.

Never had an OMP open so not to sure how it's setup.

Anyone that has had one stuck ever really looked?

Gonna go do a compression check now. Will let you know results.

Tnx Fred

 

Well, compression is good, following procedures 85 on front, 72 on rear, well within specs. Gotta really be suspecting OMP now

Fred

 

Yo,


Fred, I'm gonna throw my two bits in.

Check the connector to your AFM. When you put the new K&N filter in, did you disconnect it?

Make sure to spray some cleaner on the connector, plug it and out a few times.

I remember when mine was loose, the car would billow white smoke and run like crap.

Good luck man!

Kevin
1989 GTUs "*crosses fingers*

 

I JUST LOVE CHANGING SYMPTOMS!

Kevin,

I didn't disconnect the plug when I changed the filter. I looked at the AFM but since the plug didn't want to easily come off I didn't pursue it. Does it have screws holding it on? It looked like it but like I said I didn't pursue it.

After all of this business with smoking I talked to Don Marvel at Mavelspeed who said it's probably the oil seals. Put MMO in and let soak overnight and after burning off the MMO it stopped the smoke. Don't know if it was that or monkeying around with the OMP rod to make sure it wasn't stuck.
It was still running rough so I went back to where I was before the smoke, checking the TPS. Plugged the test lamp in and NOTHING at any throttle position! Disconnected the connector and checked with ohmmeter and it was OK. Plugged it back in and got single light that progresses to two and then none.

I'm beginning to hate this car!

With the TPS set I took it out for a test drive and I have a good idle but I still have the "chug, chug, chug" at acceleration and deceleration that was my original symptom!
It is like it is a miss but much more massive than what I have hit on conventional engines. When it does this your upper body actually moves forward and back, it's so strong.

Really grasping at straws now. Haven't changed the fuel filter since acquiring from previous owner so I guess thats my next step.

Why the hell are the filters so darn expensive? Don't seem to be all of that different than what I have put on other cars like my 280Z!

Damn Mazda!

More to follow.

Any ideas welcomed

Tnx Fred

 

the Fram G6566 fuel filter will work, not exactly OEM, but then it's only $10 at your friendly Wal-mart. You can use the bracket spot-welded to the filter to bolt it to something, or just let it hang (I actually cut the bracket off the first time & put the filter back in the OEM bracket, but on subsequent filter changes just let it sit there next to the frame- make sure the filter or lines won't chaff on anything)...if you have a bad relief or switching solenoid valve, the TPS light test doesn't work sometimes (those are the ones that "click" on & off while you're trying to adjust TPS)...also, have you checked the fuel pump inlet filter?...also, there's a clip on that AFM plug that you have to remove (or at least pull back on) to get the plug off...

 

Pulled the old filter, was pretty blocked. Put on the new. Took on a test drive, still chugged. Tried to remove connector on AFM, did not see clip on it and when I pulled (not hard at all) the damn piece that should have been screwed to the housing came off in my hands. The screws were backed out and not holding. I pushed it back in and tightened the screws and now it won't start!

I hate this car!

I removed the AFM from the car and did resistance checks and they were not right. Tried to move the measuring plate and it would not move more than 1 inch. I cut the silicone around the plastic cover and exposed the internals. When the connector went back in the contacts for the fuel pump didn't go in the right place. Removed connector and put back in the right place (I hope). Put AFM back in car and still won't start. (Will it start without the air cleaner on?) .....still won't start.

Checked the resistance and the switch is now working. How much tolerance is there for error on the resistance readings? Where the FSM lists E2 - Vs as 50-500, I read 150-500. The fuel pump contacts don't read 0 ohms but about 5 ohms. I wouldn't think that little would keep it from starting. Anyone know when the fuel pump contacts make? (How far the door is open)

I guess back to basics. Will check for fuel, air , and spark tonight.

One thing after another!

I really hate this car!

Any ideas appreciated

Fred