greenman100

I've got a spare Enthalpy ECU set up for 740cc injectors and a z32 maf...

jspaeth

This happens at all RPMs above 4000 or so....like sometimes it barely makes it past 4000 eventually, but then does the same at higher RPM if it can even make it there.

I am like 99% sure it is not a valve spring...bc initially the problem was limited to 6000 RPM...


However, what you (and Steve Shadows) mentioned about setting timing to 20* across the board and free revving is a very good idea, and one that I am going to try this weekend.


Thanks for the idea.

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Daily driven

jspaeth

I just spoke with Matt at R/T Tuning in Lansdale, PA about this issue.

It turns out that Apex'i CAN do diagnostic tests to see if the ECU is not working properly and also can "service" them

Matt said that they had a customer recently whose ECU was completely fried by a lightning strike....like completely fried.....Apex'i charged $150 to "fix" it.....my guess is that they probably just gave him a new one.....

Anyway, it is good to know that there appears to be a more affordable route other than just buying a BRAND NEW PFC....something that could cost $200 or less.....



Also, I told Matt that I could NOT get the car to start with the stock ECU setup....

He suggested that I should definitely REMOVE the 2 wires that are added for the PFC (IAT ground and sensor wire)......perhaps these are causing the stock ECU to shit itself, even though I unplugged the IAT sensor itself.




Does anyone else know the answer to that???:


If you have extra superfluous pins added to the harness for the stock ECU and let's say one of them is having constant 5V, could this cause the stock ECU not to work?

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Daily driven

2fast4y0u

finally something that seem to be in your favor.

RBMadess

run HKS spark plugs and Splitfire coils...DONE

2fast4y0u

you obviosuly didnt read ANY of the thread

jspaeth

Okay so this morning I woke up and decided to check the harness grounds. I printed out the ECU pinout and checked to see how much resistance there was between the chassis and each of the possible ground wires (2 ECU grounds, 3 injector grounds, 2 sensor grounds, 2 or 3 ignition grounds, etc etc).

So, first I unplugged the harness from the ECU, and checked a few, then I plugged it back in, and checked them all again by "back-probing" the pins in the blue plastic plug....

Anyway, all ground were exactly 0 Ohms.


So, I fire up the car, and go out for a drive.....well I drive the car for 45 minutes, and VOILA, PROBLEM GONE.....I revved the car out to redline at least 15 or so times with not a single hiccup at all.


Then I took it out tonight again for over an hour and again, not a single problem.


This is SO FUCKING WEIRD......I can't imagine that it was bad contact of an ECU pin, because I have unplugged the ECU from the harness at least 10 times in the past 2 months during this troubleshooting adventure.


Furthermore, when the problem started, I hadn't touched the ECU for a reallly long time.


Lastly, I should add that during the drives, the ECU was out in the open, not inside the kickplate.....


It seems obvious that this is either a bad connection somewhere, or still possibly the ECU.....maybe the ECU didn't get as hot today because I didn't have it covered by the plastic kickplate?



I am COMPLETELY befuddled on this one.........but also kinda happy that I was able to drive my car again (well, actually being able to rev over 4K) for the first time in like 5 weeks.


I wish I could know what the issue was so that I could feel like I resolved the issue and maybe help out others in the future....but for now, problem solved, but NOT sure why.....

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Daily driven

jamanrr

are you connections soldered or crimped? You know I had a similar problem on a Honda I owned once. It would do the same thing. Sometimes the wiring strands will stray out like one wire and make contact with another wire in the loom. Grounding out and causing an on again off again problem. Remember however unlikely you think the repair that fixes the problem is -- it has to be the solution. Sounds like you are getting there.

jspaeth

I am not really sure....someone did the swap for me 4 years ago, and as far as I can tell, they did a really good job on the wiring....have had NO electrical issues like this for 4 years, and that is with ahving moved the ECU and wire harness around more than once.

I guess it's possible that a bad connection has been the issue, but everything I've experienced has seemed like a problem that got worst as the car was on for a longer period of time (i.e. heat related).

Ugh....who knows.

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Daily driven

2fast4y0u

after all this time and research...WTF!

glad its working again though.

handinpants

from what i heard, gap the plugs with a smaller gap.....

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jspaeth

This is not a spark plug gap issue, you should go back and read the thread if you are going to post.

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Daily driven

hsitko

We fd owners are familiar with this issue. The solution that we use is the hks twin power. HKS Twin Power DLI Ignition System Harness SR20DET
http://www.rhdjapan.com/hks-twin-pow...-12353?nflag=1

We get spark blow out at around 350whp. This is the solution to 550+. This is on the fd reliability mod list and most people modifying fd's run these as a standard. Probably translates to sr20's too. But the communities are VERY different, and these units are kinda pricey. AEM makes one too but i'm not confident in their ability to make quality electronics.

mattsil80wis

i guess your another one that didnt read the thread because he bought a splitfire coipack system which is the same the the hks product


wow i cant believe no one reads?

maybe they are just trying to get their post counts up? foolish kids

anyway justin glad to hear that your car is running good...we will have to meet up and chill again

2fast4y0u

makes ya wanna beat some one

jspaeth

Hey Matt, thank you again for offering to help out with everything (ECU, coils, injectors, etc....)

I hope to come up and visit again....maybe within the next few weeks and after Cody is done training.

Anyway, did you pull the head yet to survey the damage?

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Daily driven

mattsil80wis

im in VA right now on vacation with my gf and her family, once i get back ill be installing my new motor mounts, 2 way diff, and pulling the head off the car....than ill wait til cody gets back to make sure everything is straight and slam it all together and get this beast back out on the road....i still need to get RUCA and some new front pads and i should be good to go

blkmrkt

wow i am having this same issues as well. Pretty much i drifted an event put my car on the trailer went home and unloaded it. Parked my car in the garage and went to Japan for 3 weeks. Came home and went to go redyno tune my car before irwindale. So the night before i was supposed to get the tuned, i went to go start my car for the first time since i had been back. The car would not start for the longest time, finally got it to start and it would not free rev over 4k. Changed the plugs(NGK iridium 7's) and fuel filter since im running race gas and that helped the car to start up right away and free rev to 8k. So i was assuming my car was legit and took it to intec racing for another tune. First run on the dyno and it starts cutting out, so we change out all the coil packs. That helped a little and made the car still cut out around 5-5500 but not as bad as before the new coils. So we try another new set of plugs and gap them to .022, check all the plugs again and made sure the ground on the coilpacks is good. We then tried the ignitor and still was cutting out. Although we did notice that as the car was turned off and new parts were being put on, the car would fire right up(cooled down) on the dyno and the first pull it would not cut out. But by the 3rd run or so on it would start cutting out again around 5-5500 still as the engine got warm. We call it a night and assume we'll figure it out the next day. So I was thinking why did the car run perfectly at the drift event and now it runs like shit? All it did was sit for 3 weeks while i was in japan. I decide that maybe the race gas went bad or something so we drain my fuel tank and put in 114 octane. Also we made way more beast grounds and made sure everything was sanded down paint wise for the grounds. First dyno pull with new gas and better grounds it doesnt cut, second run no cut either, 3rd run slight cut(not as bad as day before though), 4th run cuts, 5th run doesnt cut. So now it's really odd beacuse it does not seem so much of a heat issue anymore, lawrence the tuner dropped 1 degree of timing somewhere (not sure at what rpm) but by lowering the timing by 1 degree we lost almost 100hp. So right now i really don't know what the hells going on, i pulled my wiring harness and am going to go over all the ignition wires and grounds. Although i've never once had an issue with this harness. The only thing else for me to change is the crank angle sensor. Also during all these dyno pulls my ignitor chip was not grounded. Not sure if it's supposed to be grounded but i've never had issues with it not. I dont think it's fuel because i had a good AFR all the way through the pull 11.5 and when the car would cut out AFR would go rich. I have a s14 sr as well with a power fc d jetro.

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Walker Wilkerson

jspaeth

In my case, it ended up being a ground pin going into the ECU that was making poor contact.....at least I THINK.

I did every possible thing and replace every possible source of the problem and nothing helped...


Then one day, I decided to check for continuity of the ground wires going into the ECU....by back-probing each one with a multimeter.

Well, pushing on the back of the pins must have pushed the loose one into a more secure position, because since that day, the problem has been completely resolved.

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Daily driven

blkmrkt

yeah for sure my wiring harness is pretty rats nested so im going to go thru all the ground wires and ignitor wires tomorrow. I'll let you guys know how it goes, wish me luck! haha

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Walker Wilkerson