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1G Spark blowout/misfire?HELP

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rbrandona

Probationary Member
14
0
Dec 22, 2007
Pekin, Illinois
91 gsx, gt3076r, 1250 fic's, a1000 afpr, walbro 255, e85, tuned with ostrich and tuner pro/jackal on 30psi. Now onto the issue...my car runs/idles/drives/cruises perfectly, AFR is dead on and the tune is great but for some reason the car doesn't pull like it should. It has a slight miss at idle, and if I run it to 7k in 2nd gear it sounds like a Subaru and misfires. If I let it run for about 30 seconds it goes back to normal, and I can rip on it again and as long as I stay under like 6500rpm it doesn't "blowout"? The car is tuned on 30psi and should pull like a freight train, instead it pulls like a 16g on 20psi. This is super hard to explain but it isn't missing under WOT, atleast not that I know of. It doesn't go lean, or anything under wot and it doesn't jerk or anything, it just doesn't pull like it should. that's the best way to explain it. What should I gap my plugs to? and what plugs should I run? Currently on bpr7es and .024 gap. Any help would be GREATLY appreciated, and thank you in advance for reading! I will try to answer questions the best I can, the car is just being weird and its hard to explain, also no CEL.
 
My plugs are gapped at .20, I rock the weaker 16g at 20psi as you describe.... I had blow out problems at .24 and above.

And also as you describe, my issues were mostly above the 6k mark... when I had the plugs around .28 I would have the same reaction at around 5500. As I went down with the gap, the rpm it would occur went up. It stopped just below .24, like .22 or so, so I did some research on if that was safe and saw .18 was the lowest recommended, settled at .20 and never looked back.
 
Ive been told to use a step colder with e85. So BR6ES's may help. Gap it down a bit as well.

Also, do a compression test. Trust me. I had a very similar situation where i would sputter past mid 40lbs/min airflow and up. I kept playing with gaps and plugs and wires etc... come to find out had a intake valve that wasnt seating in cylinder 2.
 
Yah, 7 are colder, I would try br7es which is a motorcycle plug, it dosent protrude as much and lots of ppl have good results. Test your coil packs just to be safe and try .022 gap and if it still does it try 2 down each time. I had to gap my plugs at .016 before I got my dynatek system boosting at 32psi.
 
You're using E85... gap your plugs down! Gap them to .018-.020". Projected plugs and 7 heat range are just fine for your setup. No need to change to anything. So many people try to make this so difficult and it's really not.
 
I just went down to .020 but haven't drove it yet, but will post results when I do. This is still on bpr7es.
 
Also, compression is good, what else could be causing the underpowering issue? And how do I go about testing my coils?
 
Another thing. The car isn't stuttering all the way through the rpm range. It's literally just not pulling hard at all, and a dbb30r on 30psi should pull hard LOL. It doesn't sound like it's missing or anything. Just doesn't pull
 
Yah, 7 are colder, I would try br7es which is a motorcycle plug, it dosent protrude as much and lots of ppl have good results. Test your coil packs just to be safe and try .022 gap and if it still does it try 2 down each time. I had to gap my plugs at .016 before I got my dynatek system boosting at 32psi.

I had the same prob and did what ^ this guy did but gapped at .020
Had spark blowout right at 30psi with BPR7es w/ .025 gap.
Now switched to BR7ES w/ .020 gap and boost fine and runs perfect.

Another thing. The car isn't stuttering all the way through the rpm range. It's literally just not pulling hard at all, and a dbb30r on 30psi should pull hard LOL. It doesn't sound like it's missing or anything. Just doesn't pull

Trying Switching plugs and use gap .020
 
Coil packs can go bad and test just fine. Same goes for plug wires. Under load they can fail. Just another idea but im sure you've already tried both of those....just in case
 
What type of plug wires do you have and how old are they? This shuttering that your speaking about is most likely a missfire, but in your post you say its a missfire and then you say it's not a missfire(confusing). When it does this shuttering does it lack in power and stops pulling as much and shakes, or are you saying it just lacks in power general through out the pull? It also runs bad, sounds like a Subaru for 30 seconds after a pull with normal driving?
 
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E85 is a much colder firing fuel due to the high alcohol content and produces a lot less BTU's (explosive power output) than hotter and more explosive 87 octane.

But the advantage of E85 is the 110 plus octane that alcohol contains for high compression usage.

Thus, the suggestion on doing the slightly hotter, even though stock, BPR6ES plug would help compensate when using the colder firing alcohol fuels.
 
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I had a broken injector clip that caused the "subaru" sound you describe. Intermittently under a high rpm load (high vibration) it would lose connection randomly, I only assume by vibrating loose just enough to cause a dead cylinder.

Not saying thats it. But your description is all over the place, so your answers will be the same.

I ordered all 4 new clips for I think 8 bucks a piece. Something to look into. If your clips have a decent wiggle to them, it could be a problem.
 
Gonna try to answer as best I can. Ngk plug wires. I know my description is all over the place but it's super hard to describe without you just riding in the car. It has a slight miss at idle and cruising. Under WOT it doesn't "sound" like it's missing, nor does it cut out at all, it just doesn't have the power it should AT ALL. it pulls throughout the rpm range, just not consistently and not like it should. Plugs are bpr7es @ .020. the Subaru sound doesn't happen anymore since droppin the gap from .024 but it still does the other misses and such. Haven't tried a coil, or wires yet. Didn't think it was the coil because usually it would cut out with a bad coil under wot. This doesn't cut out, or if it does it's faint and I don't notice. It doesn't help that I have an open o2 dump so I can't hear shit LOL
 
What's your af throughout the pull and timing, are you getting any knock? Any codes? How the hell do you look at ppl's mod list, haven't figured it out yet with the new change in the site.
 
It sounds like a timing issue to me as well. It could be a bad knock sensor, or the wire to check timing (I don't know exactly what its called) could be grounded out. That would make your timing set at 5º all the time. It also makes the car run like crap.

I also agree with the above statements about trying to figure this out at 30psi. Maybe drop it to 20 and get it running right, then work up to 30. Whatever is happening isn't good for your motor and pumping 30psi into it on top of its issues is asking for failures.
 
What's your af throughout the pull and timing, are you getting any knock? Any codes? How the hell do you look at ppl's mod list, haven't figured it out yet with the new change in the site.

To look at profiles you click the number next to where it says "dsm profiles" by a persons avatar. Then it takes you to that persons page and you click on their "build journal". A mod list is now a build journal.

He doesn't have one set up, so you can't see everything that's done.
 
I listed everything that's done. And we found the issue. Switched to ecmlink for tuning, my turbo is only flowing 24lbs per minute. It's not gettin enough airflow into the engine, I need cams. Because we just leak tested it and no leaks.
 
Seems how a stock t25, on stock cams, with stock internals, on a stock car, with stock tendencies, and a stock ecu, with a stock maf, and stock injectors, and stock stockness, flows more than what you "logged"...

Its not the cams.

A 16g on a stock motor can push almost twice what you say you logged, you have other issues. Dropping $400 or more on cams will only put you $400 in the hole with a super poopy idle and tune.
 
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