12abridgeport

Finished installing msd boxes this weekend, started up the car...ran for a little bit but then stalled out. That happened before but it's usually something like flouded spark plugs or something (that's why i installed the boxes). No big deal....

But now i have tried everything and it still don't start. Got spark on all plugs, getting all the fuel to the motor, timing the same way i always had it (rechecked bunch of times), tried two stroke oil TC-W3, ATF, still don't work. Checked the compression, 80 psi with no oil and 115 psi with ATF. Also checked it by hand and it's got even no. of puffs on both sides, so no brocken seals.

The motor itself is a 12a brigey that's not even brocken in yet w/carbon seals. Have about 15 miles on the motor and a lot of idling time.

Sorry for the long post but i ran out of things to try. If i can't figure out anything else, my last resort would be towing the car down to Jesus Padilla at kilo racing.

JIMMY54

iTrader: (2)

You could always try to tow start it.

12abridgeport

That would be the last thing...i tired it before...just made me look like a fool in the neighborhood. But i believe if the car don't start with some type of oil in it...there is got to be something else wrong with it most of the time.

nimrodTT

try changing spark plugs

racintang

I'm having the same problem with my MSD setup. I don't know what to do now other than buy some more parts for a direct fire setup. I posted a wiring diagraphm on page 3 of how I did mine.

racintang

https://www.rx7club.com/forum/showth...0&pagenumber=4

vipernicus42

iTrader: (4)

How did you hook up your boxes?

Were you the guy who said you ran two MSD boxes? I don't think you can do that.. From what I can recall you run either one (on the leading) or three (one leading, one each trailing)... If you're trying to run two, in some wierd configuration, it's probably that.

Take one out and return it, run only one. If you're the person I'm thinking about

And if you're properly running the one, make sure it's wired up correctly. Other than that, put a new set of plugs in, spray some starter fluid in and crank... hope it doesn't flood.

Jon

12abridgeport

Racintang, my wiring looks very much like your 2msd setup diagram. Defenetly let me know if you can come up with something or how your direct fire setup goes.

Vipernicus42, yeah i'm the guy with 2 msd's and i'm having second thoughts about having 2 boxes, i wish i only got one.

From the looks of it i got everything hooked up the way it's supposed to be though. And i know both boxes actually work cause i'm getting spark everywhere. Also i have seen people at the track using 2 boxes a bunch of times.

I guess i could try the starter fluid. The spark plugs are new but they have been flooded before. I cleaned them up pretty good so they look almost the same color as new. The spark itself looks pretty strong too.

Also the last time i did start her up, it felt pretty strong before it stalled out but the bridgeport does that a lot when cold.

nimrodTT

What type of plugs are you using?

racintang

Use the one box setup. Run the pickup wires to the MSD Box. MSD wires to the coil, For starters, take the coil wire and run it the dis. like you normally would, I know people say it defeats the purpose but it will work for now. Run the trailing pickup wires to the ignitor, The ignitor to the coil and then the coil to the Dis. OK, Pull your gas line off of the carb, stick it in bottle or a rag, turn your car on to the on position and see if gas comes out. The problem with mine was that the fuel pump relay wire was orginally hooked to the trailing coil so when I eliminated that I eliminated the fuel pump. Took me a week in a half to figure that one out. Now for the ignitor. I gutted out the old ignitor box pre-1981 dis. and used the same wires to tie them in. If you dont know which part of what wire does what on the ignitor I can get back to you on it. Get it running and then you can add up the other coil. Just make sure you disconnect the third coil before you start it up your you will get the hell shocked out of you, Opps.

racintang

With two boxes, I would run one box for trail and one for lead. Running the boxes through the Distributor and to the spark plugs. The MSD boxes will still be giving multiple sparks. They were designed orginally to be used with distributors anyways. I'm running my MSD box through the distributor right now and it smoothed my idel out and I still have considerable amount of power.

racintang

Try using this to shield your magnetic pickup wires to the MSD box. Remember to ground it to the car. I just ordered it today so I should be getting it shortly.

http://www.aircraftspruce.com/catalo...opperbraid.php

13B4port

guys very quickly said. one MSD box running the trailing spark will not work. the fuel will be ignitated b/4 it even gets compressed. this is very bad. if you all are wondering why one msd box can't control the trailing side, well it's simple. look at the leading side and see what it's doing. in a direct fire setup with MSD both coils will fire at the same time no matter what. in the leading side this is great. when one coil fires to ignited the compressed gas in one rotor, the other coil is fired when the other rotor is in the exhaust cycle. this is good b/c it helps burn any un-burnt fuel that is left sitting in the housing. it'll help get a cleaner intake charge and also clean emmisions up. now if you put the direct fire using one MSD box on the trailing side, you get huge problems. the fuel will start be ignited b/4 it even gets compressed. remmeber the MSD box will fire as many coils as you tell it to but they will all fire at the same time. so one coil will fire when it's supposed to, but the other will fire at the same time before that rotor has a chance to compress the gas. a couple things can happen. you can get no start, very bad power loss or even pre-detonation(this will ruin an engine). so thats why you either run one MS box for the leading and leave the trailing alone or you run 3 MSD boxes one for the leading and one for each trailing. also as a tip for the MSD triggering. DO NOT USE THE IGNITOR!!!! use the mag pick up inside the distributor. the ignitor is just like the stupid wrap that they put on tools when you buy them in a box. it's very un-nessisary and is really annoying. it jsut doens't do anything. so get ride of them b/c all it'll do is dirty up the signal. to trigger the MSD box off of the mag pick ups in the distributor, take the distributor cap off, take the rotor off, take the metal protector off. youll see a green and red wire running from the ignitor to the mag pick up. cut them and run the the purle wire from the MSD box to the green wire on the mag pick up. run the green wire from the MSD box to the red wire on the mag pick up. doin't mix them up!!! if you mess that up you will advace your timing by about 30 degrees(bad news).

my sugestion to you is to take the trailing MSD box off and run the trailing threw the distributor using a MSD blaster coil and run the leading as stated above.

jerad

13B4port

well i should correct myself. you can use one MSD box for the trailing bubt you'd have to run it threw the distributor and not direct fire.

FB II

the way to use 2 msd boxes is use them as your ignitors. plain and simple. and i know it works for a fact. my puerto rican friend here does it on his peripheral port (sp?) haha. it's soooo sweet. here's a pic.

13B4port

he's runnign threw the disributor, no direct fire. h'ed gain a lot by buying another coil and seting up one MSD box to fire 2 coils for the leding and leave the trailing the way it is

praveen

i jsut cant get my 3rd gen started after a engine rebuild..im geting spark, fuel delivery to primary injectors(secondary are on only after load, right?).
maybe my battery is weak....anyone had this problem?
pls help

tk49

ONE CURE FOR EVERYTHING IS A PUSH START,NOTHING LIKE RPMS TO START A ROTARY,JUST START OUT IN 2ND GEAR,WITH THE CLUTCH ALREADY RELEASED,ONCE THE CAR HAS RUN FOR AWHILE YOU CAN GO BACK AND DIAGNOSE

jimmdog

I am no guru but, why would you need huge spark on the trailing any way? I figured with no spark it didn't make a whole lot of a change.

Keaponlaffen

Or if something major's wrong, pull starting could give the car enough momentum to break things....

Proper fault diagnosis is important in attempting to fix a non-running vehicle. I'm tired of redneck, hear-say, backyard mechanic "tricks" always being suggested as end-all be-all fixes for all RX-7's no matter what's wrong with it.

Oh, while you're on it, you might want to dump a couple bottles of ATF down the intake... that'll really help...



Try to narrow it down to fuel or spark systems... check that you've got a good supply of gas coming from the fuel pump, and then make sure it's not too much (are plugs coming out wet after cranking, etc). If both check out alright, check your spark.

It seems you've already got a good start on those things though.

After installing something new, there's bound to be something small that goes wrong that puts a halt on everything. When I installed my last engine, I missed connecting the switch wire on the bottom of the starter... This problem of yours could be as simple as something like this, so double and triple check your connections.

Also, if it ran for a few seconds, then died, and now it won't start again, check simple things like fuses, and fusible links first. If you blew a fuse for the engine 'cause something's hooked up wrong on your MSD boxes, the definately won't run.

Sorry about the rant, I'm just kinda tired with the newbies, etc suggesting things that are completely useless pieces of information, and do nothing to help with fault diagnosis. Most actually do more harm than good...

12abridgeport

The car is running now better than ever before with a single MSD DFIS through a locked dizzy. Still can't figure out what was wrong with it and why my 2nd box that went on the trailing side burned up. I actually had it start up with 2 boxes but then i noticed smoke from the wire in the front that goes to the negative side of the coil.

I would say that locking the dizzy and running a DFIS was the best thing to do. Now the motor idles 10 times stronger, setting the timing is much easier, and it doesn't stall out when cold.