Msd system now MAJOR blow by?

[J90GT]

Alrighty, i just installed the whole msd deal (box,coil,wires,rotor,cap, plugs). So i take it out for a spin seems fine get on it a bit, still seems good. Then i notice my idle goes way down to around 400 which turns into backfiring and pretty ,much not being able to idle without holding down the gas.


Im like WTF, pull over and my oil breather(yes the filter) is totally blown off, I put it back on, she runs good again. Now i get back on my street and let her rip again, except at the top of second ended in a big backfire and more crap idle i pull in my drive way and sure enough the breather blow off again.



Now, the breather cap on my car is rather cheap and just has a rubber grommet at the bottm and kinda pops in but why after i install the msd i cant even give my car some decent gas without blowing the breather completey off which inturn makes my car run like **** due to the huge vac leak it creates?

 

[nosmatt]

totally unrelated. looks elsewhere for your problem.


i would advise a leakdown test personally.......at the VERY LEAST, a compression test.

 

[J90GT]

Hmmmmmm strange coincidence i guess

 

[Black1987Stang]

u could always disconnect the stuff u just hooked to see if it could be somehow the problem, for the msd box just unplug the ground for the box and reconnect the car harness back into the stock/msd coil. Elimnate one by one and if its fixed youll know whats causing it. Always check the simple stuff first, well thats me and also the stuff that doesnt cost money to do haha Good Luck

 

[18mustangs]

Alrighty, i just installed the whole msd deal (box,coil,wires,rotor,cap, plugs). So i take it out for a spin seems fine get on it a bit, still seems good. Then i notice my idle goes way down to around 400 which turns into backfiring and pretty ,much not being able to idle without holding down the gas.


Im like WTF, pull over and my oil breather(yes the filter) is totally blown off, I put it back on, she runs good again. Now i get back on my street and let her rip again, except at the top of second ended in a big backfire and more crap idle i pull in my drive way and sure enough the breather blow off again.



Now, the breather cap on my car is rather cheap and just has a rubber grommet at the bottm and kinda pops in but why after i install the msd i cant even give my car some decent gas without blowing the breather completey off which inturn makes my car run like **** due to the huge vac leak it creates?

This problem is totally unrelated to the MSD. You've got excess crankcase pressure. Ditch the breather cap and run this cap View attachment 499842 part # M-6766-D302** from fordracingparts.com. It allows your PCV system (which ventilates your crankcase and also prevent excess crankcase pressure which can blow out your oil filler cap or have oil leak from seals) to work properly. When you run this cap (it plugs into the VC just like your current push in cap) hook the throttle body tube to the port on the cap, and then make sure you replace your PCV filter, PCV grommet, and PCV valve and make sure your PCV hoses have no kinks behind your upper intake. Your car will run much better afterwards.
Tim

 

[J90GT]

Yes, like i said maybe just coincidence cause i never had the problem before i installed it. Really hard to say a hotter ignition causes blow by unless my old ignition was just totally in the ****ty but even than thats a real stretch.


I'll try that cap 18mustangs thanks

 

[RsStanG1987]

Yeah your ignition DOES NOT have a thing to do with your blow by at all. You probabbly all ready had pretty bad blow by and never noticed it till now. Do a compression test asap.

 

[18mustangs]

Yes, like i said maybe just coincidence cause i never had the problem before i installed it. Really hard to say a hotter ignition causes blow by unless my old ignition was just totally in the ****ty but even than thats a real stretch.
I'll try that cap 18mustangs thanks

No problem, I used to be a breather cap man until I read how the PCV system works and how efficient it is (amazingly enough, the Ford engineers really do know what they're doing!). If you spend the approximately $30 for the oil cap, PCV filter, grommet, and valve you'll notice a difference. BTW, the oil cap is only $7.50 and has a built in oil baffle.
Tim