Evo8 Misfiring Issues - Need a Donor

[Falcon]

I'm looking for a local Evo8 who'd be willing to swap coilpacks with me for a quick 10 minute test drive.

I've been having some really bad sputtering at high RPMs, and have done a ton of diagnostic work to try and solve the issue. I've swapped all of the basic (and less costly) items such as plugs and wires, and I even put in a new O2 sensor. The coils are the only thing I haven't replaced, but I don't want to spend a couple hundred bucks on coils unless I know that is the culprit.

If it is the coils, its definitely not a blown coil... just a bad one, or even a bad boot coming off the bottom of the coilpack.

Is there anyone close to the Levittown area who'd be willing to swap out coils with me for a quick 10 minute drive? It takes about 5 minutes to actually swap the coilpacks.

Also, if anyone has used coilpacks they want to lend me, that'd be cool too. :mrgreen:


Check out my full thread on EvoM: http://forums.evolutionm.net/showthread.php?t=282691

Thanks! :thumbup:

[Honest_Bob]

Bad gas? My car would fall flat on its face at 5k rpms when I had a bad tank of gas. Get you some octane booster!

[markley02]

Are the VIII and IX coils the same?

[slowevo9]

yeah the 8 and 9 coils are the same. i had the same problem. i have my buddys 8 coils in my 9. my plugs were cracked and took out my coils and wires. but yeah 8 coils will work in a 9

[Falcon]

It's been going on for quite some time (a couple months), and I reset the ECU three times at least in between several fillups, so I'm not sure if its bad gas... but I guess Octane Booster can't hurt. I've got fuel system cleaner in the tank now, so I wanna run through this tank before I throw any booster in... but its a good thought.

Based on what I've tried, I'm speculating that its either a bad coil or possibly a bad/faulty injector/FPR/fuel pump. Who know.

Thanks for the replies -- keep the ideas coming :)

[RayArroyo]

yeah the 8 and 9 coils are the same. i had the same problem. i have my buddys 8 coils in my 9. my plugs were cracked and took out my coils and wires. but yeah 8 coils will work in a 9

awsome just like i thought :cool:

[peteyturbo]

What are your mods?? Any?? Why not take it to the dealer, should be covered..It's been going on for quite some time (a couple months), and I reset the ECU three times at least in between several fillups, so I'm not sure if its bad gas... but I guess Octane Booster can't hurt. I've got fuel system cleaner in the tank now, so I wanna run through this tank before I throw any booster in... but its a good thought.

Based on what I've tried, I'm speculating that its either a bad coil or possibly a bad/faulty injector/FPR/fuel pump. Who know.

Thanks for the replies -- keep the ideas coming :)

[markley02]

I just got back from his place a little while ago. The coils were not the problem. He was saying his walbro whine is not a consistant note. I know mine is a very consistant sound. Anyone else want to comment on there whine? I believe his next step is going to be to change out the pump with my old stock 9 pump. Another thing I just thought of is taking a volt meter to see what the power and ground is like at the pump.

[Falcon]

Markley - thanks again for your help man.

I think we've narrowed it down to the fuel system. We'll start with the pump and go from there. Testing the voltage isn't a bad idea *at all* as the inconsistent whine may be a result of faulty wiring. Who knows what the hell the previous owner did. :)

[Suckface]

just out of couriousity, is this sputtering happening when you are driving the car in fifth gear on the highway, or is it constantly happening at the mentioned rpm's in any gear at any speed?

[Falcon]

Its RPM related... so, if I'm in 4th gear on the highway and mash the throttle down (say at 3k rpms) it will spool up nice-nice, and accelerate perfectly until 6k rpms and then sputter.

Same thing in any gear. I don't see the problem as much in 1st or 2nd, but I get through the top of those gears so quickly, its difficult to really tell. 3rd and 4th above 6k is where it is most evident now.

Gonna try to swap the fuel pump when its not 100 degrees out and see where that takes me. I've got my fingers crossed though. :)

[Falcon]

So I swapped out the fuel pump tonight... and I'm getting the _same_ freaking problem.

I've tried
* plugs
* wires
* coils
* intercooler hoses
* fuel pump

This is beyond frustrating. It's not throwing any codes, so I have no idea how to narrow it down at this point... the only things I have left to check (that make sense to me):

* voltage going to the fuel pump (as suggested by Markley02)
* fuel pressure at the rail (no idea how to test this)
* injectors (I guess if the pressure at the rail is good, but I'm running lean, it might be an issue with the injectors - no idea how to narrow this down though)
* fuel filter (there are apparently two, I'll have to research on how to replace the in-line one)

Any other thoughts?

My car is virtually stock at this point (Evo XI fuel pump on an Evo VIII is the only "mod") and I have a base 2004 Evo VIII map in the ECU. I'm running a BR7ES -- maybe I should try a BPR7ES?

[markley02]

I was looking at your early logs on evoM. Your accel enrichment reads 200 in evoscan. According to MalibuJack (which is almost like a god when it comes to the evo ecu) the value should be 0-100 only. What that means..... I have no ****ing clue. Just something else that is wierd.

Lesson learned: never buy a used evo. lol. You never know what the last idiot did to the damn thing!

Compare these numbers to the accel enrichment chart in your ROM

RPM %
500 1.625
1000 1.5
1500 1.125
2000 1
2500 1
3000 1.20312
3500 1.32812
4000 1.42969
4500 1.42969
5000 1.42969
5500 1.42969
6000 1.42969
6500 1.42969
7000 1.42969
7500 1.42969

[Falcon]

I'll take a look.

This may be a NOOB question, but whenever I look at certain maps via Evoscan, I can never see the full value of the number because the table is too small. You can't drag the table and make it larger, and I've tried changing the resolution on my laptop with no luck there.

Is there another way to view the actual value?



** update/edit
Something I posted on EvoM:

How noticeable is the stock boost cut? I've never really noticed it hitting at 5k... is it possible that the ECU is expecting a boost cut, and is going wacky because its not happening for some reason?

Also, I have no idea regarding Accel enrichment...

[markley02]

Have you tried logging 2-byte load at all? With the load calcs you are running you should not be near fuel cut, but them again that is calculated load not 2-byte load. I don't know that much about the accel enrichment and from searching it doesn't seem like anyone else knows either. lol. If changing the fuel maps (which were different) didn't change the problem that pretty much discounts the ecu being the problem.

It almost seems like the old owner kept seeing it go lean so he changed the fuel maps to compensate. When that didn't work he turned it back to stock and it was still doing it. Which would be why the front O2 sensor went bad. Not from fouling, but from the uber hot EGT's!

The messed up Accel Enrichment is confusing as hell, but who the hell knows if that is the problem or how to correct it.

If you want to check the voltage or swap injectors sometime let me know. Just not when it is 90+ degrees out.

[Suckface]

I have no issue with boost cut or it trailing off above 5,000 rpm's which some people experience. my car holds boost strong all the way to redline......

you could try running bpr8es pplugs from NGK, these plugs run only on step cooler than stock and most evo guys will tell you they are the best plugs for the car.....that's what I run in mine....

good luck man, i know what it's like dealing with a used evo and an almost unsolvable problem, but I finally got mine kick in the ass, so hopefully you will too

[Falcon]

Thanks for the support guys... I've got my fingers crossed.

Suckface: Do you think the BR8ES would work, even though I'm stock? It already seems to be running lean up top; wouldn't a colder plug only make that worse?

Markley: Swapping injectors isn't a bad idea... we could try that, too. In a few weeks, we could also just swap motors. :D I'm not sure what the timing has to do with this particular problem, but it definitely goes nuts at higher RPMs it seems.

The previous owner definitely had a laundry list of mods. Just from looking at the car when I first bought it, I could at least pick out exhaust, intake, intercooler, and ECU flash. So, who knows...

[Falcon]

I ran a boost leak test tonight with a new tester, and I can't keep any pressure in the system.

From what I can hear, there is a decent air leak by the throttle body; from playing around with stuff, it seems to be where the throttle cable armature connects to the throttle body. If I push in on it (towards the firewall) the leak slows. This isn't a gasket, as far as I know - the seal between the TB and the intake manifold seem solid.

Even still, I'm not sure how a leak like this would be causing such a pointed loss of power and causing the engine to run lean.

Any thoughts?


Also, has anyone used ScanTech? What a POS... It kept reading a P0000 (FF) code. I have no idea what that is, and haven't found anything about it yet on EvoM.

[Suckface]

the plugs didn't seem to lean my car out at all......and I am basically stock.....as far your boost leak is concerned even a slight drop in pressure will cause the car to stumble all over itself, especially when in high rpms and full throttle......good luck man, hope you figure it out!

[Vince@R/TTuning]

Aaron give me a call when ya get a chance i might have some time to check it out this up coming week. And was wondering if your gauges came in?

[evomike]

take it to the dealer stop giving yourslef a headache

[Falcon]

I took it to the dealership; they're a bunch of tards and ended up pretending to void my warranty over the fuel pump.


Vince: I will give you a ring tomorrow. The gauges were shipped on Tuesday (from NY) so they should be arriving soon... :)