nonameo

My engine cranks rough and most of the time it won't start. Could this be my ignition coil(s) going bad?

It started this as I was pulling up the driveway.

1FastT2

iTrader: (1)

It could be a hundred different things, an easy way to check to see if your coils are ok is to hook up a timing light up to each of the spark plug wires and see if each coil if firing while you crank the engine,

nonameo

Well here is what I have done:

New gas (no premix)

Checked for spark, so getting spark when sparkplug is OUTSIDE of engine

Cleaned sparkplugs that are in the engine (this helped for the next crank, but was just as bad afterwords)

Checked drain on battery

Performed De-flood method

Checked AFM

It also smokes a lot and smells of gas.


Also checked the sparkplug wires for continuity and they seem fine.

I will do the haynes coil check shortly.

nonameo

Can't find my haynes manual, wahat is the procedure for checking the coils?

nonameo

bump

Rx7Nub

I'd like to know the answer to this aswell, with my car, if I start it up cold, it starts fine, but when I have been driving a little distance and turn it off, then go to start it up again, it has trouble, it will start, but takes a little while... what do you guys think? Coils for me? I also heard poor compression can also make it hard to start the car, and I also have a bumpy and high idle once my car is warmed up, I was wandering if this might be poor compression, and could this be nonameo's problem aswell? Thanks..

-Mark

StarionX

Welcome to MY world. For me, after the restart, I get very slow acceleration, and sometimes very little boost. I would say not enough spark.
I've narrowed my problem down to to the coils or the ignition wires (much more likely it will be the coils), but... it's too freakin' cold out, and I can still drive it so I am going to wait for Spring.

Rx7Nub

Well... at least I am not the only one... Starion, do you have a fuel cut off switch or anything? I got one of those... but I don't think it's the injector's, because it starts fine sometimes and not other times... I was thinking it's the coils too...

StarionX

Fuel cut switch, you better believe it (this should be the first modification on any RX-7 ). After I finally got my vacuum leaks fixed, the car almost runs fine. I've had a 'warm-start' problem for about 2 years, which is why I have the fuel cut switch. I've also replaced all 4 injectors with new ones.

After you finally get the car restarted, does it drive with no problems? If so, you don't have a problem with the ignition coils, just a 'warm-start' problem (engine flooding). You could have leaky injectors, or the compression on the engine could be getting a little low. The fuel cut switch will get it started with no problems.
If you have the same problem as me after restarting it (rough, slow acceleration), probably a spark problem (spark plugs, ignition wires, ignition coils).
Have you pulled the codes from the ecu?

Rx7Nub

I have a fuel cut switch, and I use it to turn the car off, and I still get this problem, I changed the spark plugs not too long ago aswell... and I got a bouncy as hell idle right now from like 1500-1700 over and over... only when the car is warmed up though... when it is cold the idle is perfectly fine... except it is high... like 1500.. I think I need to adjust the tps, do you think I should replace all the vacuum hoses with silicon aswell... the car always runs fine after it is started.. it is just hard to get it started. I haven't done anything with the ECU at all... I don't quite know what my problem is.

StarionX

The high idle you get when engine is cold is normal. If the cold-assist is working ok, you should see the engine rev to 3000rpm for 17 secs, then it should go down to about 1500, then eventually go down to 750 after engine is sufficiently warm (everything working perfectly of course ).
If the idle fluctuates when engine is warm, it could be a vacuum leak. There's no harm in replacing all the hoses with silicone (it's a PITA to do, hope you have lots of patience or a knowledgable rotary mechanic ). If it's a steady high/low idle, could be TPS, maybe even the BAC.
If the car runs fine once it's started, then your main problem is it is getting flooded on restart. Many different causes for this. If you don't mind using the fuel-cut switch, then I wouldn't bother fixing it unless you have the money. You may have leaking fuel injectors, low compression (apex seals going bad, or OMP could be failing so that the engine is not gettting any/enough oil)... could be anything.
I recommend looking at the following site. It has great information about TII's.

Rx7Nub

Mine dosn't go up to 3000 at all, just to like 1500 and stays there, then after a little while it starts to bounce up and down alot from 1500-1700... not quite sure what to think...

Zach McAfee

That is exactly what mine does when it's really cold (freezing) out, but once it gets warmed up it stops. It sounds like a ported engine but then goes back to normal.
It didn't used to do it, and when it's warm it goes up to 3K just like it's supposed to.

Edit: I have MSD leading coils.

Hot_Dog

Best way to check the coils is to use a peak KV tester and measure the secondary voltages of each one. You can get a peak KV voltage tester from Actron for $30. Check out this website:

www.actron.com/cgi-bin/web_store.cgi page=cp7870.htm&cart_id=1305847_9460

(If this doesn't work, go to www.actron.com, then "Garage sale" then "Test equipment".)

A timing light only gives you a "go" or "no go" indication. You really need to know the voltages that the coils are putting out.

Hot_Dog
90 GXL
02 RSX-S

nonameo

I got it fixed. It was just flooded! thanks anyways though, and I found my manual too.

But if you have a cat-back or turbo back exhaust system you want to get rid of, IM me.