SSCoulter

iTrader: (4)

I installed a new cam over the fourth of July weekend. The car is running great except for on occasional problem starting. I will turn the motor over and it doesn't start. Turn it again and it will hit just fine. Then every once in a while on the first try it will not start and as the motor is stopping it's rotation I here a small hiss of air gurgle out the back or a small back-fire. Other than this issue, it runs it's *** off.

Question:

When we did the cam install and we were pumping the lifters up in place they all responded immediately except for one. We held this one up with a pin magnet. Could I have a lifter problem? The valve train is as quiet as stock. I mean no noise at all. The guy that helped me install the cam who has installed many was even surprised how quiet the valve train is. Anyway, this one lifter we had to hold up is bugging me. Could this be the problem? Maybe the valve is not seating all the way and air is getting in the engine when it's not supposed to. I have no more ideas and I need some help.

Thanks!

SSCoulter

iTrader: (4)

Anyone? I know with all the experiance you guys have on this board somebody can help me.

Dan_the_C5_Man

The lifter tray not holding up a lifter should have nothing to do with your issues..

Installing a new cam w/o a tune might though.. The other thing that might be an issue is the cam position sensor..

code4

iTrader: (30)

I'm not an expert but if you had a lifter collapsing on you it would be very obvious ie; loud ticking & you would have a miss. I don't know what could be happening but I would double check all connections etc.

SSCoulter

iTrader: (4)

Ok great thanks guys. I will rule out the lifter being the issue. The tune I will have done this week the hold up has been the dyno or lack there of at my local performace shop. I have had them do a "basic" tune which was raise the rev limiter and turn off SES light and so forth. I didn't think wideband tuning would have anything to do with how the car starts, rather a/f tuning on the top end. Am I wrong?

Tell me more please about this position sensor. Where is it? How do I check it?

blkZ28spt

The tune will absolutely help the way it drives. A typical basic tune can't do anything but raise the idle speed, which helps but doens't do a whole lot. A proper, hands on dyno tune will make it run 100 times better. I don't know the specs on your cam, but the larger it is the more it needs tuning in order to run properly.

PREDATOR-Z

Why do you seem so astonished since you don't have a tune????

Tune it.

SSCoulter

iTrader: (4)

I'm not astonished. I just have never heard anyone else say they had small back-fires when trying to start because of a lack of tune. Did you even read my post? For the love of God I understand that I need the tune. If the back-fire issue is because it needs to be tuned so be it. But I have yet to see where anyone else has had this particular problem. Run like crap, die at idle, surging. I have heard of all of these problems BEFORE a tune but never about the back-fire. I just wanted someone to say "yeah that's what mine did" or "gee, never heard of that before" or something, anything helpful. Has anyone else personally had this particular issue after a cam install? Anyone at all?

SSCoulter

iTrader: (4)

Thanks, but your pointing out the obvious. I know it will run better with a tune and I will have that done as soon as the shop gets the damn dyno ready. But how does that have anything to do with a small back-fire when I'm trying to start it? That's the question I need answered please.

The cam specs are 226/226 .591 on a 112LSA.

blkZ28spt

Take this for what it's worth, but i wouldn't worry about the small backfire. Not only is your car likely running rich, but after an attempted start there will be fuel in the exhaust that did not burn. The small backfire is probably just that fuel being burned. No guarntees that it's not something else though, I'm no expert.

If nothing else I would avoid driving it until it is tuned and/or you get a specific answer about the backfiring.

SSCoulter

iTrader: (4)

Thank you. I will let it sit untill the dyno is ready. I hope it will be Friday.