Need help with ignition problems (new engine)
 

Some of you may have seen my build thread (link below). We finally cranked the engine last week and it started in first go super smooth. Ran for 20 seconds. Second go started again but after that it didn't start. Looks like we are having ingition problems. It may also be related to Power FC or datalogit I am not sure. I'm listing the issues and actions below. What should I check, remove, replace next?

- The car started with lots of white smoke, turned the workshop into a nightclub.
- The tuner was adjusting the power fc but the car died.
- It is wetting the spark plugs a lot.
- No ignition.
- Crank angle signal is OK, ECU reads revs.
- Removed power fc installed oem ecu, still no ignition.
- Removed HKS twin power, still no ignition.

My build thread:
https://www.rx7club.com/build-thread...ssible-989042/

Test ignitor?
Test coils?
"No ignition", did you put a timing light on each wire to verify?
What did the tuner change specifically in the PFC?
Did he start with a fresh basemap?

May also just be flooded. New engines do NOT like to be shut down cold, if it only ran 20 seconds, was shut down, was started again, was shut down again, you probably flooded the engine.

Crank the engine over with the plugs out and no spark to get some of the gas out of the chamber. Get some new plugs - on a FRESH engine that you're dialing in, just run 7's in the leading, even if you won't run those long term, they will have a tendency to foul less as they're a hotter plug. At this point you're not hard-core tuning the engine, you just want to get it running, idling, and let it warm up.

Dale

How can I test the ignitor and the coils? The tuner started with a fresh map afaik.

We tested the crank angle sensor it shows 240-250rpm while cranking with plugs out.

We may have flooded the engine but eitherway we still don't get ignition. We tested with plugs out etc.... I will use 7s in leading like you've suggeted.

Testing the ignitor and coils can be done with a multi-meter per the FSM. Ignitor sits where the cruise control module was on the drivers side wall.

Foxed.ca - Mazda RX-7 Manuals

I ask about the timing light because the pickups can be creating a signal, but if the coil is not pushing an actual spark via the ignitor then you won't know. With an inductive timing light, you would know if the signal was making it through the plug wire. Furthermore, you could pull the plug, attach the wire, and ground it to the UIM and crank it to show an actual spark.

Also, when deflooding the engine as Dale mentioned, make sure you pull the EGI fuse first. This will disable the injectors and spark as you crank the flooded engine. You don't want a fuel mixture spraying from the plug holes with your dangling wires sparking... You can get an engine fire easily this way. Place a good size rag next to the spark plug holes as the mixture will spray out a bit.

We will check the coils today but according to the FSM we need an igniter checker to check the ignitors which we don't have.

as XLR8 suggested i would check for spark by just removing a spark plug wire and either attaching a spark plug tester ( easier and safer than removing the actual plug) and be sure you have a spark on each spark and trailing wire. if no spark trace your steps, check and verify power and ground going to the coils, just basic process of elimination

Also check the wires going to the coils it is easy to switch the trailing wires. This will cause you to flood out really bad...ask me how i know.

Thanks guys. Findings so far:

- We could not check the igniter because we don't have an ignition checker.
- Ignition coils are checked. A-B primary coil winding is 0.6 ohm (within spec) but L1-L2 secondary coil winding is 27kohm (out of spec).
- Coil with single exit A-B primary coil winding is 0.6 ohm (within spec) but A-T secondary coil winding doesn't show figures (spec sheet says infinity).
- My friend will give me his spare coils and igniter and we will test with them.

If the problem is my coils or igniter, should I buy OEM replacements or can I improve the ignition system for a similar cost? I already have a HKS Twin Power but should I buy MSD or another brand of coils? Which brand or model would you suggest?

As you mentioned, you have a few choices.

1. Replace the OEM - Depending on what is wrong, this may be the easiest route. You do have the twin power in place and it doesn't seem to be the issue. The TP does a good job of pumping up the stock system, if the stock system is in order. However, over the years the OEM system does wear and fail, as you may be experiencing. I have personally seen 500whp on OEM coils with the TP many times. As long as everything is in check it will do it. But like all systems, it falls to the weakest link. If you stick with the OEM system, I highly recommend replacing the leading coil with a new one, Magnacore wires, and NGK race plugs. I am running this setup at my power level with no issues. I plan to hit 500whp in a few months.

2. Aem IGN-1A coils - As innovation takes over, things change. AEM has hopped on the bandwagon and recognized the IGN-1A coil as a very valuable solution. These coils essentially put out the same mjouls as the TP on an OEM system. However, they do house the ignitor internally and work well with the 3 trigger system of the Power FC. The following thread supplies a lot of valuable information. I recommend reading it and looking into these as a viable option:

https://www.rx7club.com/3rd-generati...nstall-992444/

CRAP! We cancelled the HKS twin power, then replaced the coils with the ones I borrowed of a friend (which are in specs according to multimeter) then replaced the igniter. Still no ignition :(

Cranks angle sensor works fine with spark plugs removed we see 200-250rpm at first crank, this is normal right?. Tried both oem ecu and apexi power fc. Ran out of things to check. It's weird cause the car started at first go then we lost all ignition at 3rd try.

Any ideas?

I will do some research tonight and post back. You need to start verifying continuity through the system.

Ok I will try and I'm looking forward to your reply.

Meanwhile if anyone has any ideas or suggestions please chime in as we are stuck atm :(

Would a new wiring harness fix my problem?

Sorry I haven't had a chance to research this.

Just a shot in the dark, but did you verify the EGI fuse isn't blown?

The ignition signal to the coils and igniter flows through the body harness. Under the dash, through the drivers side fender, and up through the engine harness. The igniter wiring takes the short route and comes through the small hole under the fender. As you can see, it's quite large.

The coil harness is a small separate harness. It is replaceable. Verify continuity through that as well.

Yes, we checked all fuses, none blown.

Ok, will do. Thanks for the suggestion :icon_tup:

The fact that you lost all ignition on the 3rd start is odd. It can only be a few things here.

- ECU
- Igniter
- Pickups
- Coils
- Plugs
- Plug Wires
- Wiring harnesses

To track down this dodgy little issue you are going to have test every component individually, as well as how they work together. You must comprehensively follow the signal from each component to ensure its operation. Something isn't doing its job.

This should help.
https://www.rx7club.com/3rd-generati...iagram-964089/

Hey XLR8, and everybody who replied, thanks a lot for trying to help. I've been told the problem was a faulty igniter and when they changed it with a new igniter they did not install it fully which meant it wasn't grounded properly. Also they looked at some wiring inside drivers side fender like XLR8 suggested which helped troubleshooting so thank you again :icon_tup: