COP running really bad.
 

I have all my Cops installed and it does run however it has a misfire at low revs which I cant hear or tell if its there at higher revs/70mph. Every so often the exhaust will bang as if fuel has ignited in the exhaust.

My Tach has also stopped working. Do I still need to do the 1K resistor MOD even though im running a DIYPNP?

Also I couldnt understand where the 2.5ms dwell rating was entered on tuner studio. I changed cranking to 3.5 but where do you cnage dwell to 2.5?

Would that cause it to run like a bag of s**t.

the dwell rating is as measured at 14v, so you should use 2.1ms and then tune your battery dwell correction table to match the curve that jason has mesaured.

that will bring up back up to ~2.5ms when running


yes on resistor.


running like shit = bad wiring job? did you gap the plugs out too large?

0.8mm gap

try gapping them out to .11mm

0.11 thats tiny.

Just searching for the graphs from Jason and I found a page which lists some dwell setting but not sure if this is it?https://www.miataturbo.net/showthrea...ighlight=dwell

These figures?
10V: 5.9 mS
11V: 5 mS
12V: 4.25mS
13V: 3.75mS
14V: 3.3mS
15V: 2.9mS

i meant 1.1mm or ~.040"


yep, so you gotta do some math assuming the dwell number in the spark settings is based around 14v and you know you run at Xvolts when cruise around, you need to convert his final numbers into a percentage and plugged into your battery-dwell curve to get your desired output.

You have lost me there.
So based on what you said at 14V that should be 2.5ms. Then im lost sorry.

i dont know what curve you just posted but Jason measured the ideal dwell curve for the Toyota COPs at:

9v = 3.4ms
10v = 3.1ms
11v = 2.8ms
12v = 2.6ms
13v = 2.4ms
14v = 2.2ms
15v = 2.0ms
16v = 1.9ms


so under your ignition settings you should use 2.2ms as the dwell value.

But what is your voltage when the car is running? 13.5v as reported by the MS?

So your correction curve needs to make sure that at 13.5v you dwell-battery correction is 105% and 140% correction for 10v.

makes sense now?

if 2.2ms = 100% then 3.1ms = ~140% and 1.5ms = 68%

so:

9v = 3.4ms = 154%
10v = 3.1ms = 141%
11v = 2.8ms = 127%
12v = 2.6ms = 118%
13v = 2.4ms = 110%
14v = 2.2ms = 100%
15v = 2.0ms = 90%
16v = 1.9ms = 86%

Brain why would increasing the gap help the misfire?

i dunno, but that's where it should be at now with these coils; but i fear the issue is a bad coil and/or wiring.

Thanks for the figures that explains it much clearer. Just need to get my laptop sorted out now and then change the dwell settings and my ignition table.

As I suspected the car is still running very lumpy. I change some of the settings in the dwell correction table. Only problem I had is that there wasnt enough points to set each of the values set above so I nevr had the dwell correction set for any lower than 10 volts. Is there a way of adding more points to the graph so I can input all the figures above.

I fear I may have damaged some or all the cops. I hope not but still the car runs very lumpy

Is there a way to add all the figures to the dwell correction table? If not what voltage should I start at or shoul I just leave 13v and the odd numbers out and assume that when the curve passes through that point then it's the value above.

I mean I just did the math for you, if you cant figure out how to apply that to a table...hint, you don't need all the data points.

The dwell is not your problem, it's either wired incorrectly (eg. firing order) or the coil(s) themselves are bad.

I appreciate as always your help Scott, Just wanted to be sure so I can eliminate that as the problem. My wiring was ok. It wasnt the best but I would think its fine. Only things I did a bit crappy was I never had full lengths of wire for each wire on the cop and then solder them to the correct points on the connector. I joined the cables that could be joined with as short a wire as I could get away with. That might mean that 4 wires where soldered together and then 1 wire went from that to the connector. Other than that I cant think of an error with wiring. The CAP is in and must be right as its not blown up :D

COPS yes they could be damaged. I have 1 spare so I could do a swap on them all and see if it goes.

Assuming I input the figures above I assume the COPS shouldnt now get damaged (Yes if they are already damaged they will still be)?

I need to use the car tomorrow to travel 100miles. Just hope it gets me there and back.

My revs are up and down like a yoyo any suggestions on what this could be. I have changed max dwell to 2.1, cranking is 3.5 dwell table is
6V =200
9v=154
10v-142
12v=118
14v=100
16v=86

Ok so I left it running for a while and the revs seemed to stay constanta fter a minute or so. I have chaged the gapos to 1.1mm up from 0.8mm. When holding a constant rev the engine idle drops then recovers. I have took a small clip to try and show you. i will upload in a sec.

View My Video
It may not be the best footage but you can here the small miss as it ticks over then when I rev it and hold it at the same revs you can hear the engine tone drop then recover and do that several times.

Any suggestions?

I tried swpping all the coils 1 by 1 with my spare new cop and the engine note still drops. TBH I think this may have been there before going to COP as I remember when the crap tuner was tuning the car and he held the revs at certain revs and then adjusted the timing/fuel the same sort of thing been there.

Any suggestions from watching the video?
Is it normal or does anyone else have a similar thing where if you hold the throttle constant at certain revs the engine dips the revs then recovers?

These "problems" can be due to all sorts of things not necessarily related to your COPs. Stuff like AFR, airflow wierdness, idle valve, vvt.

What happens when you actually drive the car?

Anytime I've ever held the rpms constant and it did that it was because that area of my fuel map was highly untuned.

the engine idles like they are all firing.

Bit of update. I drove the 100 miles today with a few observations. The car was running hotter and the temp gauge almost went up to 3/4 which is much hotter than normal. Afr guage was at about 16 but would flick back and forth to 14 depending on my throttle position. It would make the gauge rise when doing 70mph. If the timing want correct that would cause the engine to over heat wouldn't it?

It also would start missing when I took it on boost around 5 psi ish. Only changes I have made are to the area of the ignition map below 100kpi. I used the table above that starts around 33 in the bottom right corner. I copied all the figures and left the rest as the map was. I never made any alterations to fuel.

It does smell rich I think. I also set the gaps back to 1.1mm from 0.8

Double post from my phone sorry

Dude you need to learn how to tune a fuel and timing map and when and why.

You also need to learn how to look at the logs.

If you did what Brain said your dwell should be fine.

Do a pull in 4th gear to redline at WOT and log it. If you go lean (above 13AFR) in boost, lift. Look at the AFRs in the log. If they're fucked, correct your fuel map. Relog after you adjust. Don't touch timing for now. Keep going until your AFRs look good. Then report back on your results.

If you are missing I recommend decreasing the gap, not increasing it. I would start at .5mm Brain may not agree and that may not produce max power but it should be a consistent spark and eliminate that potential issue.

Thanks for the advice. I have no laptop at the moment but when I get one I will do some logs and report back. Thanks for the advice.

Could to much timing make the car overheat? I assume it may be running lean and therefore could be overheating

Whose timing map are you running?

Post a screenshot of your timing map.

Running lean in cruise won't make you overhheat. EGTs are also highest at stoich.

Your overhheating is probably an unrelated issue.

https://www.miataturbo.net/attachmen...ine=1311966391
This is teh map im now using. I entered everything under 100kpa (Not including the 100kpa line.

The car idles with a miss fire. But weirdly it goes then comes back but most the time its there.
If you hold the revs constant below 3k it missfires every 2 secs or so.

It wont take the boost it feels like it hits the boost inhibitor even though its only at 5psi.

Im having a play around now but its hard work as I still havent got a laptop. Is it possible for someone to show me a fuel table that would match the ignition table above so I can compare?

Would a bad tune cause this miss?

I did a bit of reading about the setup of the tuning when idling and there was a piece which mentioned tuning the car so when it trys to jump with the revs it knocks back the ignition and so idles perfect. I cant think where the hell I red it can anyone elaborate on this as I cant find wher I read it first?

I think you're talking about the ECU pulling/adding timing to try to hit an RPM target at idle.

Honestly, what you're talking about doesn't sound like a big deal. How does the car drive?

I changed the map slightly using the other map from my other post "how do you get 300bhp..."

I changed the spark plug gaps back down alittle to 0.9mm and that seemed to resolve the idle dropping issue. I also turned off the EBC function as im still on MBC at present. I then took it for a drive and gave it WOT and it seemed ok for the first 2 pulls. Maybe alittle bit of pinking from the engine and holding back slightly. Then I took it on the bypass (Freeway) and again WOT and it started to miss under boost. Its like there is too much boost and the fuel/ignition isnt right to cope.

Thats the feeling I get. I never had any of these problems before going COP so I cant understand hy it would happen now.

I tried to get the revs to stop dropping today by keeping the revs at about 2100rpm and then adding and removing fuel from the fuel map to try and see if it helped. Strangly sometimes it stopped and then it would restart. But most the time it would keep dropping.

I noticed a change in the tone to the engine so I started to pull of the connectors for the COPS and 1 of the COPS had failed. So I changed that for a spare I had and then continued removing the COP connectors and I noticed another had gone! (Didnt sound like it was on 3 or 2 pots but when you removed the COP it wasnt clicking away as they do when the spark is arcing to the plug just as you remove the COP).

Am I melting COPS like no tomorrow as thats 3 gone now?

Or do you think they where damaged previously before I changed all the battery Dwell and they just decided to give up?

It makes sense in some respect as the car was misfiring on boost badly. Just hope I havent got something wrong thats causing this problem.

On a positive note the Revs are working now thanks to the resistor MOD.

Any thoughts would be much appreciated.

Just replaced a coil and now the car seems to running excellant. Im going to set the gaps back to what Brain recommended and play with the tuning as it is pinking at high boost I can hear it as I give it WOT.

Its strange how its just started I never noticed any pinking before.

Full boost will usually be above 100kpa range wont it?

My ignition map has changed under the 100KPa mark but above its still the same. Thats the only think I can think might be causing the pinking.

I sense imminent engine death

I hope not!

I will have to go and really try and listen but im sure it did pink. Maybe its time to take it back to the same tuner but just for him to make sure there is enough fuel and ignition at the top end of the map.

Either that or I give it a go myself.

This will be you.

https://www.miataturbo.net/attachmen...ine=1312669248

lol

how did you determine which cop to replace?

threadjack

I've had a problem with start-up since installing COPS, for the first 5-10 seconds after startup, there's a miss, after which the problem goes away completely. Occasionally the car will die during this 5-10 seconds. If the A/C is on when the car is started, it will almost always die. This only happens if the car has been turned off for 30 minutes to an hour prior to starting. It seems more prevalent if the engine is still hot (leaving a restaurant) than if the engine is ambient (leaving for work in the morning). It is not repeatable a second time in succession.

I made 2 changes at the same time - I changed to COPS; and at the same time, I also removed the EGR system. I made no changes to the tune when I did this, and the problem began. I have since made changes to post-start enrichment, fuel map, dwell, idle airflow, etc., and have been more or less completely unsuccessful in solving the issue.

Any suggestions?

very low timing will cause high egts and can cause overheating. Grab a timing light and double check.

I just removed the connectors and listened to the engine note. Then I pulled the cop up alittle bit and on a good coil you could hear the spark clicking as it arched bak to the plug. when I pulled a bad one there was no clicking noise and so either no or a weak spark. Its running great now but I cant determine if I have pinking. I have been giving it WOT most the time and its still going so it cant be that bad or it would have blown by now.

Just on with modifiying the exhaust at the moment as it was to low. When it fixed I will try an listed for pinking and report back but I think all is well:bigtu:

(zack morris's phone)

ping. Not pink. Its and adjective describing a noise not a color.

In the UK it is, in fact, called pinking. I sh*t you not.

silly brits.

Please check your compression when warm, and post results.

Note: When the engine is cold, empty the water reservoir tank, fill up the radiator, and go for a drive, boost it to redline, and then check how much water went into the water reservoir once it is cold again.

How much time does it take for the engine to go from cold to warm?

Will it heat up if you let it idle for 10 minutes or so after a good pass of under boost?
When was the last time you changed the radiator cap?

Does is still hesitate whenever you start boosting? I read you said like around 4 to 5 psi or so...

LOL Yes it is called pinking over here "Knocking (also called knock, detonation, spark knock, pinging or pinking) in spark-ignition internal combustion engines occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front."

just because they call it that, doesn't mean it's correct ;)

I'm still getting the pinging. Just reduced my ignition map by about 3 on each of the higher values and it's ticking like a time bomb. The original map as bad as it was had the highest values at 7k rpm set at 25. The other values where less and at these values all seemed well on the pinging front.

I changed the map to one posted on my other thread and essentially this made the map look nicer and the highest value went up to 37 at 7k rpm. All the values seemed to flow nicely on the graph. However this ignition advance is killing the engine.

Is it a case that the ignition looks correct with a map like the one a few posts back and is it time to alter the fuel map? Or is it time to revert back to the original map but tune it to look better and flow instead of been rough?