I have noticed a slight miss while in 5000+rpm range. I have 240K on my motor and wondered how long the stock coil lasts...

 

Could be a weak coil, bad wires, etc, but it's probably shot valve springs.

 

If you think it's a bad coil start with this test-

http://shbox.com/1/coil_testing.jpg

When I performed this one, my stock coil was showing some funky readings, and it only had 138k on it. I replaced it with a Crane coil, but have heard the stock is pretty good, and if you source it online you can get it for $30 or so if you know where to look.

These ignition systems are a bitch to diagnose and troubleshoot, so be prepared to look into it further when you find stuff that's bad and start replacing it.

 

Kevin...

Anyway i can determine if its infact my valve springs? You are you saying i am getting valve float?

If it were the springs wouldnt it happen consistantly? This problem seems more hit or miss.

I will start with the simple items first... Plugs, wires, coil

 

Yeah, simple stuff first. I had a 5000+ rpm miss and it was the coil wire. Then I had a 6000+ rpm miss after that and it was the coil itself.

 

Good plan. Do the easier, cheaper stuff first - not that plugs & wires is easy . That's a tune-up. If it was springs, I would think that it would be consistent, but same goes for ignition, unless it's heat related and those problems are best solved by substitution of parts. at work, we boil a coil in hot water or run it with a heat gun pointed at it and see if it fails - but that's hard for a guy to do at home. I can't tell how you're equipped, but understand that the stock valve springs are marginal in the upper rpms when new let alone the kind of mileage you have on the clock.

 

Well the guy i bought the car from didnt exactly take care of it. I pulled some plugs out of the car that look like they had gone through a nuclear explosion. When i did the tune up for some god for saken reason i didnt change the plug wires... we pulled one plug and the connector looked all nice and shiny -- but that doesnt mean that the entire length of wire was toasted.

As for the valve springs i'll probably just leave them for now. My focus is on building up the car to handle massive power later on. So now my focus is on stiffening the frame and such.

 

Still having problems dubb? Did you ever get that fuel/start up issue fixed?

I would say coil also. Coil - spark plugs - wires, only things to check other than opti.

 

Shibby!

Whats up?!

Yea still trying to sort things out.. but this car needs some serious TLC. Shibb.. it turned out that my FPR was toast. It was so bad that when i went to relieve the pressure at the rail not a drop of fuel came out!

I am a nut bucket for not changing the plug wires when i did a tune up!

 

Ha! I knew it!!! I even made some little start up diagnostic thinking about your problem on my site.

About the miss though. It really can be almost anything since it is missing erratically. But, coil is the first thing to look at. You can try that test on shoebox's site that FastZ posted. Although any meter that measures ohms works, mine is small enough to fit in my hand.

EDIT: I just remembered someone told me his car had a miss, and it was the coil sparking to the outside of the housing. He never found out how to fix it unfortunetly. So that might also be a cause.

 

Yea yea..

Well i'll start slow and work my way back towards the more expensive part. I was just interested in know how long does the stocker last. I think after you hit the kind of milegage i have.. all bets are off anyhow

 

What is also entirely possible is that my tach is off and when i think i am at 5,000 i may be higher.. and bouncing off the rev limiter. I am also looking at an after market shift light for more accurate shifting.

 

If you are bouncing off the rev limiter you'll know. I bounced off mine constantly when my tranny died and couldn't get out of first. 6100 rpm and 55 mph, that was a lot of fun. It makes a weird sound and the engine will act like it is going to die for a split second, than regains itself, and than does it over and over.

Stock parts can last a long time, like mine have lasted 182k (knock on wood), but 240k is another story. Plugs, wires, coil, opti. I always liked the method of going from cheapest to more expensive.

 

Well thankfully the opti was changed prior to me buying the car :-D