Governmule

Hey guys not sure if this is the right area to post this or not but I want wanted some input on if I should start my car without a tune or not. I have an intake exhaust and tune right now. But I just installed a cam, pushrods, valve springs, oil pump, timing chain, and injectors. Would it be safe to start the car just to see if it will leak anywhere or should I just tow it to the shop and get a tune and hope for the best?

subeone

iTrader: (5)

nothing will happen you can turn it on.

jsteele90

iTrader: (13)

I would not recommend starting the car untuned with the larger injectors. You run the risk of washing out the cylinder with fuel. Which is very bad. I took my injectors with me to my tuner and he changed them out for free when i did my cam swap.

LSX Power Tuning

iTrader: (4)

Great advice, I agree 100%

Burken01

iTrader: (88)

How quickly can you wash the cylinders out?

1 min, 5 min, 20 miles?

Burken01

iTrader: (88)

When you tune vehicles that are rich, and it takes you 5-10 min to get it running in the safe zone

How much damage if any is being done while your tweaking the car during that 5-10 min window

MontecarloDrag

iTrader: (3)

I always advise my customers to bring me the car using stock injectors to avoid washing the cylinders and fouling the plugs. It takes me 15 min to install them
I prefer to install injectors for free than having to change spark plugs, some cars are a nightmare to change the plugs. I never tune a car with fouled or old plugs so it makes my life easier changing injectors myself.

Burken01

iTrader: (88)

Ok but if you start to wash the cylinders, how long would it take to do damage?

If its rich and you only have a handful of start ups and 20 second idles vs driving a car that's rich and putting 50 or more miles on ot

thunderstruck507

iTrader: (18)

you don't seem to know how tuning works, the tuner will pull the stock tune and alter the injector tables as well as some other things before he even starts to tune the car

it's not just as simple as being "rich" or "lean"

Burken01

iTrader: (88)

Even after adjustments some tunes still need work once the car is started hence recording a log to see what's goin on.

But while your recording a log and tweaking things it's overly rich for x amount of time till you correct everything..

My question, does the fuel have enough time to cause damage during the initial stages

COSPEED2

iTrader: (7)

It can but only if you let it run for an extended amount of time before you modify it. If there is dark smoke coming out or white smoke that smells like raw fuel you may want a few more sets of spark plugs. Those normally go first. Then the O2s. But sometimes all that fuel will wash the rings as well and that is always bad. Hard to come back from that.

COSPEED2

iTrader: (7)

Also depending on the inj size change your engine can choke itself to death on fuel just idling trying to warm up. I would def recommend a startup tune before you cause any issues.

Burken01

iTrader: (88)

I totally agree, how quickly can you wash rings? Within seconds, minutes or miles?

COSPEED2

iTrader: (7)

Minutes to miles depending on how large the transitions are from stock or whatever tune is in it.

We do offer remote tuning services that can help nearly anyone understand the basics and we can either assist with the build/tune from start to finish or just help get you on your way. Our tunes are personalized and unique to every car and combo not just some generic copy and paste and a slap on the ***.

Remember though when it comes to tunes and injectors, alot of the time you get what you pay for. Stay away from ebay throttle bodies and ebay injectors. Also if you call up a tuner or vendor and they havent heard of the brand...best bet is to stay away. Quality tunes not only come from quality tuners but also from quality parts.

LSX Power Tuning

iTrader: (4)

It doesnt take that long to get the a/f close, maybe a couple minutes total run time if that. When I fire one up I already have the laptop logging and the wideband on, I look at the a/f and shut it off. Make changes based on how far off it was and go again. Even if its way off the first it only takes a couple tries to get the a/f close enough where it isnt hurting anything.

There isnt any set time limit before damage can happen. I wouldn't even risk it with bigger injectors if it were my car. At a minimum you'll most likely kill the plugs within a couple of minutes. The risk isnt worth the reward IMO.

joecar

LTFT's may possibly be able to trim... the problem comes in if the LTFT's peg and/or CL is not achievable.

And, the amount of injected fuel during transient throttle/air events will be incorrect.

Regardless, there is NO reason/excuse to run with incorrect injector tables.

COSPEED2

iTrader: (7)

I have seen fuel trims max (either way) with the install of a relatively small cam by todays means.

Better safe than sorry and have to pay more later.

MontecarloDrag

iTrader: (3)

It's not a matter of time. It will happen, the larger the new injectors the sooner.

If you are driving 5 miles or 500 without a starter tune, it's much better to leave stock injectors so fuel trims can compensate for part throttle and no damage will occur. There is no point using large injectors without a tune, period.
If you sold the old injectors or they are bad, send the PCM for a mail order tune, then you can drive the car safely.

danieloneil01

Tuners will not only load the new injector data but also make many more changes to the tune before starting it up. One of those is increasing the VE table across the board a certain %. Idling the car once this is done has a wide range to be safe at to see where it's at before strapping it down and going ***** out on the dyno. I've been as low as high 9's AFR for a mile or 2 at part throttle before shutting down and making adjustments.

Burken01

iTrader: (88)

That's what I'm getting at, when you were high 9's for 1-2 miles is that enough time to wash and do damage?

I guess it's too subjective since nobody checks after something like that happens