I was having problems with misfires in high boost about two months ago. Turns out it was a blown head gasket. I replaced the head gasket, was able to boost and all was well even through the night before last.

Yesterday the wires that are connected to the MSD coil blaster, the ones that are spliced into the distributor and have to go through the disti cap, got caught up in the disti rotor and cut one of the wires. The engine shuts off, I fix the wire and the car starts well and runs fine at idle and part throttle. However, it is misfiring bad in boost again... this time it is at a lower boost level than last time (12 psi vs 18 psi).

It could very well be that I blew the head gasket again, but I did a compression test and it was fine (180 across the board). Oil and coolant looks good. I'll do a leak down this weekend.

I checked the rotor out real good and it does not look like it has a problem.

What do you think?

 

Were you having the same problem w/o the MSD parts? Most people 'upgrade' to MSD because they think they have to, not because the OEM parts are having problems. Then they encounter issues or the MSD parts break/fail, then they revert to stock (if under 500whp), and do a real upgrade to M&W parts if stock can't handle it. If you search the site, you'll find I'm not making this up.

There are many people using 100% OEM ignition parts to do 12-18psi on large turbos, so unless you're using 94mm turbo at 18psi, chances are stock parts will work.

The only thing besides that I could suggest is you check the HG mating surfaces for flatness. Using slightly warped parts will lead to eventual HG problems, ones you can't detect with a 14.5psi absolute (0 psi) compression test.

 

I have had the MSD stuff for a while.

A leakdown test would show problems with the HG though right?

Also, I did notice that there is a tiny bit of play in the rotor... very little but noticable. The play is left to right (rotation/circle) not in and out. I wonder if the wire catching the rotor put just enough stress on it to cause it to get a little loose.

 

a leakdown test won't show up on most hg leaks because 100 - 150psi isn't enough to break through the gasket.

a better method to check for a hg leak is to remove the radiator cap while the engine is running. if it's bad, bubbles will come up through the neck.

You can also feel your hoses after you boost. if your hg is bad the pressure will cause the rad hoses to become real hard

 

OK, I'll try that after work.

What are the odds that I am having dizzy problems? It is just strange that it worked fine the night before the wire got caught up in the rotor and I had problems after. It could just be a coincidence as I noticed some familiar white smoke a little bit this afternoon from the exhaust.

 

My b16 was misfiring at the dyno, i had to change the spark plugs to colder ones and fixed the problem.

 

I thought it could be that too b/c I had just changed the plugs before it started happening. I kept my old plugs and put them back in but the problem persisted.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jewjew bean &raquo;</TD></TR><TR><TD CLASS="quote">a leakdown test won't show up on most hg leaks because 100 - 150psi isn't enough to break through the gasket.

a better method to check for a hg leak is to remove the radiator cap while the engine is running. if it's bad, bubbles will come up through the neck.

You can also feel your hoses after you boost. if your hg is bad the pressure will cause the rad hoses to become real hard</TD></TR></TABLE>

wha?
squeeze me?

ok i cant even interpret your cyl leakage test.

removing the rad cap will show you a leak if it is blown to a water jacket. wont show you a between cyl pop.

and i can go out to my driveway and squeeze my rad hoses and they will he hard. i just got home and the car is at opperating temp.

hi profile is correct on the MSD stuff for the most part. i am saying that based only on the fact that i have had a blaster ss and a 6AL on my car for 7 years now he hee. no issues.

what is your gap set at on the plugs just out of curiosity? and what other dammage was done when the rotor caught the wire and wrapped it up?

 

Will report back on the leak down this weekend.

Gap is set to 25, same as it has been for 2 years. This is on NGK 8 step cold plugs. I usually can run up to 27psi with these plugs.

I just hit it hard in third starting from low RPM and it started to misfire as low as 4000 and 7psi. I was able to get up to 15psi last time I blew my HG. Coolant looks clean and compression test is OK.

No other damage was done, it just tore through the wire. I was able to resplice it back up with no issues. Like I said, the rotor has a little play but it may have always been like this. I tried to check the other connections on that wire to the Dizzy and it looked OK.

 

yea if your upper radiator hose is bulging when the car is completely cold that COULD show something is up with the h/g...

what plugs do you have and how much boost are you trying to run? what gas is in the car?? Is the wire on the dizzy taped back up, anything like that needs to be soldered back together!! For ***** and giggles if you can get another dizzy, try swapping out some internals, BUT you should just start with the basics like your plugs and look from there first.

 

Radiator hose is not bulging, not bubbles in the coolant, coolant looks clean.

Just put new plugs in, NGK 8 step cold gapped at 25. This is what I allways run without issues. I run boost as high as 27 psi with a lot of methanol on top of 93 octane.

I can't go above 12 psi now. It is like hitting a rev limitter.

 

you need to get that spliced wire **** out of there and throw it in the trash. nothing is good as a solid wire with no interuptions. for all you know the spark could be jumping to one of your handy splices and causing **** to happen.

 

Thanks, I think you nailed it. It was the positive wire that broke and now since it has two splices in it (the orig and the fix), I am probably getting too much resistance to fire off the heavy fuel injected on higher loads. I just talked to MSD and they said to hardwire the blaster coil to the battery to issolate the issue to the wire itself. Also, they said it is probably not my rotor as that would cause a problem throghout the load/rpm range.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaveF &raquo;</TD></TR><TR><TD CLASS="quote">you need to get that spliced wire **** out of there and throw it in the trash. nothing is good as a solid wire with no interuptions. for all you know the spark could be jumping to one of your handy splices and causing **** to happen. </TD></TR></TABLE>

Well, I went in to look at the wires and it turns out that the other wire which did not get torn must have got caught up a little but never tore. However, it did pull at the origional splice and I think it was loose enough to loose some voltage. I am going to get in there this weekend and put a solid wire from the distributor to the coil and hope that fixes it.