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View Full Version : Misfire Big Time 2nd Gen



tdw6974
03-08-2006, 12:13 AM
Well saturday replaced plug wires and plugs. car ran fine. Went out tonight to finish installing tach Started and darn Thing is mis-fireing god awful. Acts like its got only one plug fireing. Maybe we cooked one of the coils when we where trying to get tach hooked up. Fun Fun. HELP!!!! TW

lateapex911
03-08-2006, 12:58 AM
I had a 2nd gen turbo that was famous for that. It would often flood. Went thru a lot of plugs. Have you put a timing light on all wires to see if they are firing? Checked the plugs? Anything else, the 2nd gen guys will have to chime in, LOL.

C. Ludwig
03-08-2006, 06:14 AM
89+? Limp mode?

tdw6974
03-08-2006, 07:27 AM
89+? Limp mode?
[/b]
1986 but with a s Intake Limp Mode? ECu 326? TW

Eagle7
03-08-2006, 07:33 AM
With a problem like this, always try fresh leading plugs. I don't thing the trailing plugs matter much, so I wouldn't bother with them.

RP Performance
03-08-2006, 08:22 AM
With a problem like this, always try fresh leading plugs. I don't thing the trailing plugs matter much, so I wouldn't bother with them.
[/b]

While the trailing plugs do not work as much as the leading they can get real wet and not fire at all. Tom, it sounds like one rotor is flooded and not firing at all. Is that the first time that you ran it after installing the plugs? Check your firing order also, make sure nothing is crossed.

tdw6974
03-08-2006, 09:18 AM
While the trailing plugs do not work as much as the leading they can get real wet and not fire at all. Tom, it sounds like one rotor is flooded and not firing at all. Is that the first time that you ran it after installing the plugs? Check your firing order also, make sure nothing is crossed.
[/b]
HMM ok I may have croosed something up. I looked is Haynes and factory service manual and I don't see anything on firing order other In haynes it of course it explans the T and L marks on the housing but on the next page it says "the boots of the leading (upper) spark plugs are Blue and the trailing(lower) spark plug are black." end of quote So maybe I have crossed wires. As I look at the Engine on the plug side. Upper left is T1 Upper Right T2 Lower left is L1 lower right is L2 I think. Is there a manual "Rotary for Dummies" ? probably I have crossed wires Actually on Saturday it Ran Fine but when missed fire started I may have crossed something looking for cause.

Eagle7
03-08-2006, 01:28 PM
Your hookup is correct. 1 is front, 2 is rear. Top is trailing, bottom is leading.

Additional info: The leading plugs always fire together twice per revolution - once when that rotor needs it and once when the other rotor needs it. You could swap the leading plug wires and it would still work fine.
The L1 combustion firing is when the timing marks on the crank pulley are visible. L2 combustion is when the timing marks are straight down. A mark on the pulley opposite the timing marks can be helpful in diagnosis.
A fouled plug may prevent the timing light from flashing for the combustion fire.
I can start my car with one rotor flooded/plug fouled. My dual EGT gauge is quite helpful in identifying that condition, as the flooded/fouled rotor will not heat up.

P.S. Make sure you're not out of gas. I spent an hour the other night troubleshooting a new setup before I noticed the nearly empty cell. ;)

ITSROTARY7
03-08-2006, 04:22 PM
You postd that you hook up a new Tach. Where did you get the Tach feed from. Dissconnect the new tach and see if miss goes away. I have found that some tach feed back thru the coil. You might have a bad Tach.

C. Ludwig
03-09-2006, 05:11 PM
1986 but with a s Intake Limp Mode? ECu 326? TW
[/b]


No. If you're using that ECU then it's not limp mode. Swap in a fresh set of plugs. If that does nothing do a compression test.

RP Performance
03-09-2006, 11:16 PM
Tom, did you find the problem?

tdw6974
03-10-2006, 07:20 AM
Tom, did you find the problem?
[/b] YES :D Finally got back at it. I think it was a combination of all suggestions above. 2 Plugs where soaked, I found out the Firing order and even discovered that the Coils are marked according to proper hook up :rolleyes: The tach is now working after calling Auto meter and finding out which wire to Snip ( the colors where different than noted in instrctions) Dumped 10 gallons of Pump gas in (oops there goes the Fuel sample) so with all put together We are back running :OLA: Thanks to all for the help! :023: Even the weather looks good today! :eclipsee_steering: TW

slydrite
03-13-2006, 02:56 PM
1986 but with a s Intake Limp Mode? ECu 326? TW
[/b]


hi all.....brand new to the forum here.....

I'm wondering if anyone can descipher this coded language?

I have a new to me 89 ITS RX7 and it has the limp mode issue......cycle the key and all is well for another ten laps or so........previous owner changed oil metering pump, ECU, mass air sensor.......I changed intake air temp sensor........no check eng light ever comes on and all temps and pressures are good.......learning on the fly is proving difficult :( :unsure:

any and all help is mucho appreciated

MaxEnergy
03-13-2006, 09:39 PM
Talk to Andy at Flatout motorsports. I trouble shot a similar problem for an entire weekend for a friend of mine and didn't fix it. They took the car and made it right in short order. Obviously the distance makes that impossible but he lurks here and may be able to give you some direction.

ITSROTARY7
03-14-2006, 12:41 AM
Had the same problem about a year ago. Found one of two things where a problem. We went through 3 Oil metering pumps ( turn out all had bad wiring), Second we found the pins into the ecu were bad (under vibration we found that a couple of pins where no longer contacting).

It would be a good Idea to check the Oil metering pump if not brand new or check the ohm readings of the wires from the oil metering pump and the Ecu.

benspeed
03-14-2006, 10:57 AM
Slydrite - take that puppy to Flatout. I had a legendary problem with my car stuck in limp mode. Had the entire garage of ITS RX7 drivers trying to fix it up at NHIS last year. We did 20 + hours of work, changed OMP twice, coils, new wiring harness and more AT THE TRACK. Only got it fixed after going to Flatout who did the trick and next weekend I won my first race - had some power under the hood that was missing too!

slydrite
03-14-2006, 06:04 PM
I wish I could just take it somewhere and have somebody wave the magic wand........I'm on the other side of the country...........

anybody have contact info for 'Flatout' ?

is it Flatout Motorsports?

maybe they can help me over the phone......

I'll try google

lateapex911
03-15-2006, 06:36 PM
www.flatout-motorsports.com

Search for Andy Bettencourt here....he posts all over the site, and PM him and he will get you a number or a suggestion. Last seen on the Jensen thread.

I don't know the SF area but there have got to be some gurus out there as well. It can be a vexing problem.