Good evening! I have a question regarding cold/hot starting that I would appreciate some guidance on. I have been reading quite a bit about this topic here, but I'm still not quite sure how to proceed. Hopefully this will help someone else as well.

I just replaced my coils, wires and plugs on my '07 with 24k miles. The old coils definitely looked rough, and the spark plugs..... I should have taken pictures!

Anyway, I got slightly used BHR coils, wires and new NGK plugs to throw in my 8. It definitely runs better while driving! Much smoother over all, and it cruises at 70mph a few hundred rpm lower than before.

But it takes longer to get it started now, and it's the same whether starting cold or hot. It used to take a second or two tops. Now it takes about two to three seconds and it stumbles a bit before it finally starts with a quick squeak that I definitely don't remember. Leading and trailing plugs are in the right places with the corresponding wires for each. Also cleaned the MAF while I was at it with some CRC MAF cleaner.

What do you all think?

 

You might check to see if you dislodged a vacuum line.

 

Do you premix?

 

Just email Ray from BHR and ask him. He's a great guy for help.

 

At first I was going to suggest you verify the plug wires are going to the correct plugs and that the ground cable is connected to a good unpainted grounding point, but you mentioned the car runs fine once started.
Since this started happening after you changed out those components, I would go back to the OEM coils and see if the car starts like it used to. The BHR coils normally wouldn't cause starting delays but you did say they were slightly used and you may not know how they were handled previously.

 

I think a bad coil would likely throw a CEL for a misfire.
To be sure, they could be tested a lot easier than swapping the whole thing out again.

 

Not all the time.
I had issues with my BHR coils causing starting issues and never saw a CEL.
Installed new OEM coils and worked fine.
Keep forgetting to call Ray and ask about that...

Some people don't have tools to test coils (like an inductive timing light).
And its not like swapping coils is a difficult task anyway...

 

I'm currently having a similar issue, my BHRs have about 13K on them. I thought it was the plugs as they looked horrid, but after changing them, still the same. I still have to do some troubleshooting to find the root cause, If I have time this weekend I'll drive to the garage to do some more troubleshooting and let you guys know.

 

Go pick up a timing light from Harbor Freight, it's easy to test the coils.

But keep in mind, it could be other things, my starting issue was only after the car sat over night or for a few hours and it ended up being a slight leak (smelled nothing because my car always smells like gas, ) at the fuel tank. It was a warped nipple on the pump assembly so the fuel line would lose pressure over night, then take an extra couple of seconds to start while it pressurized the line.


bad:





Good:

 

Thanks for the info 9K, I'll be checking everything, at first I thought it was my battery as the + terminal was corroded, but after cleaning it, nothing changed. I then check the plugs, but same results. That's why I'll be taking a few hours to check, as it could be just about anything, old battery (original from 09) ground, coils, vacuum leak or fuel issue.

 

How bad was the corrosion? If it made it into the battery cables that could still be your issue.

 

Bad, that's what I was thinking, got to inspect the cables to the starter.

 

BTW, OP sorry for hijacking the thread, I was going to start one after finding the root cause, but I figure you could benefit from what I'm seeing/find.

 

No no, please post in this thread if you want. Really appreciate the input, it's all good info! If you do spend some time on your car this weekend, I'd be interested to know what you find.

I just checked to see if I bumped a vacuum line, looking good there. One thing I did notice while looking around was how the wire is attached to the second trailing spark plug. It definitely clicks into place, but it sits away from the plug a tad more than the other wires do, like there is a bit more plug showing between the wire and the engine. I can push it onto the plug further, but then it slides back to where it was. Do you think this could cause an issue?

Also, I'd be game to get a timing light to test the coils. I'll google about how to use, but any advice would be helpful!

On a separate note, is there a grounding point that works best?

 

If you feel the connection snapped tight, then you may be able to slide the boot down over the wire a little further to keep it in place.
It probably isn't a factor, but you never know.

There are beaucoup threads about grounding points and kits, you should look into it and decide for yourself.

 

Quick update, did some troubleshooting today. Re-checked the battery terminals and wires, seemed ok, but cleaned them again just in case. I found the connector under the + battery wire to be a little dirty so I cleaned it. Checked the BHR harness ground and added a couple of serrated washers for kicks. Inspected mass airflow sensor, throttle body, air filter and starter, all looked good. Rear spark plug cables were off the clips, so I hook them again (one may have been grounding out). After all that, the car started better, but not the same as before, used to start after one sec, now it takes 2 to 3, sometimes 4 like a BP or one with bad plugs. Even tried with a jumper just to make sure it was not my battery, still the same.
Since winter is coming and we hibernate our nice cars my next steps are to find my OEM coils(could not find them this morning), buy a compression tester and a bunch of goodies to install, in addition to de-badging the 8, and re-engineering the front grille so a little body work.
I may have a few good weekends left, but the issue may be fuel related and not electrical, so may take till April/May to find out. Keep you posted.

 

Did you check the fuel pump?

 

I did not, that's my next step, fuel system. Pump, filter, injectors, pressure. Just not in a real hurry to take crap apart since the weather is getting to the point where I stop driving her. I may drive with dashcommand and verify the fuel pressure today (I think is monitored, not sure) since the rain is supposed to hold off till tonight.

 

So I had the day off today and after my wife had me move a shelf from the bedroom, clean up and reorganized the shed and garage for winter, I got a chance to look for my old coils, and luckily found them.
When to the garage and did a quick swap to see if that was the issue and indeed it was. So replaced them with the OEM ones ( they have about 24k miles on them) until I get these to Charles. I'm editing a video to show the difference and post it after I'm done.

 

Just finish uploading the video, see below. One thing I did not realized is that I had stop smelling the awful exhaust from being decat, now that I have good coils again, my eyes watered as I was parking the car back in the garage, something it has not happened in a couple of months, so most likely the coils have being degrading for a few months. I suspect one of the trailing coils was getting worse than the others as I was not getting any CELs or any other issues other than the startup and (what it seem to me) running a little rich as I was popping like crazy, maybe a little hesitation at 4.5k RPM and was not getting the awesome decat RX8 smell.

 

[Coils] you never know until they go...

 

I just replaced my coils (B series) with C series coils from Mazmart. I didn't notice any difference after replacing the wires, plugs, and coils all with OEM parts on my 2010 GT. I'll post more updates on interesting things I learned later in the Series II Tshooting section.

 

Just got an email from Charles, guess I'll be checking the coils to see if they are really failing.
Since I don't drive the car in the winter, and I go to my buddy's shop to do any car work, the test may have to wait 'till spring, unless my buddy has an ignition tester. Definitely not taking this **** apart again with only a day or 2 left of nice driving weather .

 

I know Charles, not knocking you, but my years of troubleshooting tells me this is the issue. I will comply with your request as I know you have to deal with a lot of other people that don't even want to try to find the root cause to issues.

Just venting a little, too late in the season to have time to get it done. Started looking online for bench testings as to avoid taking all the crap apart, and I hate "real live" testing with questionable part if I can help it, specially if they could cause permanent damage to the car. Having aviation experience, "do it right the first time" was imprinted in my brain and some of the coil testings are questionable in my opinion, just my 2¢.
I may opt for the fuel pressure test and comp test before I try that other method you suggested, seen how the car differ from the questionable coils to the "known good" coils".

I'm pretty sure you know how your cars handle/run/sound/perform/etc. I'm pretty **** about my vehicles, so I definitely know the difference was night and day, but I see your point as a business man and I will provide you with the info you need. Might take a few months but I'll post it here.

 

I know Charles, we may just have 2 different ways of troubleshooting, I start from the "wall out" until I find the root cause, and if found, I rarely place the offending issue back in the unit "confirm" the issue. To me, that's cause for trouble.
Live and learn I guess, I know now for the next time (not if) it happens.