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Spark blow out maybe???

1K views 13 replies 4 participants last post by  MY 85 GT 
#1 ·
How long do spark plugs last on a turbo set-up mine are around a little over a yr...I had a water pump failure so I replaced that I installed a flex-a-lite fan..then I was having very low battery voltage so I bought a PA performance 3g alt upgrade ok did that today..took the car for a ride seems nice charges awesome...But now when I get on it start building boost 5 psi and the meth injection activates I get a bog like it cant take the fuel...im thinking spark blow out...plug went bad..got wet from weak spark from low amps before I replaced the Alt?...Any ideas air fuel gauge is reading fine not going lean at all..if I drive the car normal its fine only does it once I go into boost...Oh also car is running anywhere from 180-195 temps im guessing that ok...any help would be great thanks...
 
#2 ·
Whats your plug gap? You running standard stock plugs? hotter, colder?...more info needed. If you just wanna do something just for the sake of trying it close the plug gap by .05 and then .10, see if it helps any. Not an authority on boosted 5.0s but my old GN had meth injection and I didn't have it coming on til 15 psi. Was running a total of 26 psi and closed my gap to .35 to avoid blow out at high boost. 15 psi really shouldn't do it.
 
#3 ·
I checked 2 plugs yesterday there champion i hate them the shop that did the install used them not my 1st choice...gap was .030 i have a cran HI-6s ignition,MSD coil,Msd wires,cap,rotor,...THE CAR DID NOT DO this for over a yr it started doing this when the water pump let go i replaced the water pump.while in there i installed an electric fan...at the time i had the stock Alternator I thought because the stock ALT coulndt keep up i had weak spark..so i just installed a 3G alt yesterday took the car out..runs great going into boost it bogs...almost like it isnt taking fuel...AGAIN...it didnt do this until the water pump let go and i put the electric fan on....
 
#4 ·
It's possible you have a fouled plug caused by the weak spark- only way to tell is pull them and look. The passenger side is a pita, the down pipe has to come off.
I'd probably replace them since they are out no matter how they looked.

Have you checked base timing since the water pump replacement? Possible it got bumped/moved when everything was apart?
 
#5 ·
Thanks no the timing didnt move at all its marked...lol...How hard is it to take the down pipe off can i leave the exhaust attached???? Im trying to see what plugs to use im not using champions again...lol Im also going to close the gap up to .025 too
 
#6 ·
Do you have the on3 y pipe?
The downpipe has a vband at the turbo and under car at the ypipe. Use something (jack stand, etc.) to hold up the y pipe and then release the vband clamps on both ends. It isn't too bad. Hardest part for me is my strut brace needs to come off first.

I use Autolite 23 plugs gaped to .030
 
#7 ·
Ok cool thanks..yes i do have the ON3 y-pipe...i have trickflow aluim heads 170 cc so i dont think the sutolites would work...the 2 plugs i pulled out were gapped at .030
 
#8 ·
Make sure all the hose and clamps are attached. When I had my SR20det I kept blowing off my hoses and it would run fine and put around but when I got into the boost it would fall on it's face.
 
#9 ·
What hose...the intercooler piping couplers? Thats what it feels like..drives normal hit boost it has no power...
 
#10 ·
Yes......1234567
 
#11 ·
New
Before I take the rest of the plugs I did a little more research..I found 2 vac caps dry rotted im guessing from the heat of the intake/ Underhood temps from the turbo I have a Trick flow street heat intake..under the upper intake there are [2] 3/8 vac barbs that had vac caps on them they were leaking bad..i didn't even hearany vac leaks or see it on the Air fuel gauge which is weird...But can a vac leak cause this bog...Someone said that its un-metered air so it could effect it...Do you think that is the issue?? I did get into boost hard the last time I had it out before the water pump went and then I did the electric fan thinking it was the Alt draw,,,were then I did the new 3G Alt... I was going to get 2 pipe plugs and take the barbs out and install the plugs so this wont happen again then just try taking it for a ride and see if doesn't Bog what do you think????​
 
#12 ·
Yes good idea. Vac leaks will wreck havoc.
 
#13 ·
Fixed the vac leak still doing it...I had my wife watch the Air fuel gauge today when it did this bog/stumble she said the AF goes rich the very lean and its very erratic looking not steady of course I let right out of it....I have no idea what to check now..
 
#14 ·
EDIT car is fixed....
Someone suggested to turn my metrh off and i did,by turning the Meth off it allowed me to find the real problem...lol..when I wired the Autometer Water temp gauge up I got lazy and I tapped in the MSD coil for the Light...well wouldn't you know that isn't a good thing to do...When I shut the meth off it allowed me to stay in the gas a little more because with the meth on it bogged really bad so with it off I hit the gas heard pop pop then the light blew on the gauge and the car took off pulled over turned the meth back on ITS FIXED...car is running back to normal..I have a big smile on my face that the car is running again.....
 
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