PI HAT

Just finished up heads, rockers, intake manifold, TB and flo-pack. The car runs like ****, but is drivable. It backfires pretty bad the SES light flashes periodically, and idles high (about 2k), when not in gear. I have an appointment to get it tuned on Monday and have to drive it about 70 miles. The drive up there is mostly 55mph highway. I know not to get stupid with it but what do you guys think? Will I do any serious damage?

RE AND CHERYL

iTrader: (31)

If your tune is stock and you just installed the stuff in your sig including the injecctors, I would not drive it 70 miles at all.

PI HAT

The tune is not stock and yes, the injectors are new too. What damage do you think would happen?

ls1leadfoot

iTrader: (1)

Anything Could Happen......find A Person With A Trailer.....i Drove On A Stock Tune Just Cause I Was So Excited And Ended Up Spinning 3 Rod Bearings!!!!!......at Idle It Was Rich And At Speed It Was Lean......dont Rush.....it Will Happen.....hurry And Do It Twice.....take Your Time And Do It Once.....
Good Luck

myfast70

iTrader: (38)

If you put the stock injectors back into it you may be able to get away with driving it to the tuner. I just did a cam, intake, tb swap along with a bunch of other parts and need to get my tuned next weekend and was told that for the drive I should use the stockers and change them to the 42 #'s when I get there because I run the risk of either flooding the engine or washing down the cylinders. The computer doesn't know that you just put larger injectors in it and it uses the same pulse width as the stockers and fires them just the same as stock. The problem that you run in to is that with a bigger injector and same pulse, they will dump a lot more fuel into the engine. I may just swap mine to the larger ones and trailer it it to the tuner. I'm not really in the mood to change them out after a long drive and on a hot engine. IMO

Websy21

iTrader: (34)

This is what I was told to do by a tuner, keep the stockers in and change them when you get there. Just limp it there and be easy on the gas. This would very on what mods were done but you should be ok. I will only be doing heads and a 224/228 cam so I am not too worried. Its good insurance to be safe though

myfast70

iTrader: (38)

I threw my LM wideband in and just kept my foot out of it and it was about 14.5 on the drive home. You should be fine so long as you keep you foot out of it.

RE AND CHERYL

iTrader: (31)

I would not drive it with those injectors installed. Those injectors are rated at 36lbs at a much lower pressure that the LS1 fuel system runs. In reality they probably flow 45-48lbs at 58 psi. Your dumping way to much extra fuel in the motor just from the injectos. With out putting a wideband on it there is no way of knowing what the A/F ratio is.

70 miles aint no trip around the block. I know it would be a PITA, but I would trailer it.

Re'

Tram

iTrader: (14)

This is a great thread..

I am about to do a heads/cam swap and will have to drive 2.5 hours to get the tune done..

If I leave the stock injectors in there, should it be ok?

bowe1632

iTrader: (1)

what are these ppl speaking of with a "mail order" tune ive seen in other threads...??? I thought you just went and had it dyno'd or tuned at a tuning shop.

SweeTbone

iTrader: (8)

That's a challenge. Stock injectors might keep you running, but H/C on an A4 on a stock tune, your **** will want to stall everytime you stop.

Mail order tunes can be had if there is no dyno with reasonable distance of you. You basically tell them all your mods, send your PCM in, and they will flash your PCM with a tune that is close to perfect. By no means will this squeeze out every HP and Ft/lb, but it's worth it if no dyno is present. The other "mail order" tune type is when you send your PCM in just adjust to your new injectors and mods, making it driveable, then you drive to the shop for the full dyno tune. This is the option I'll be doing. Send my PCM in, get it back 3-4 days later, install back into my TA making it driveable and drive down for the full dyno tune.

Websy21

iTrader: (34)

I agree with him, depends on what your mods are gonna be. If they are extensive like h/c and blower than it would be smart to get a mail order tune close enough that you could limp it without boost to get it dyno'd. I too have a 2-2.5hr drive to nearest dyno and am gonna ahve to do this. I bought my car with a mil order tune and since my mods at the moment are fairly mild it was just of matter of squeezing out a little more performance. Plus it helps alot with an automatic being able to change shift points, etc.

PI HAT

Ok, understand that the injectors are not good because they will dump way too much fuel, but the only thing that I think will happen is backfire...right? I can deal with that. About half would do it or have done it. Of the ones that are saying DONT drive it, I havent gotten any reason besides too much fuel. I dont have a trailer so I think I will easily drive it up there. Thanks for all the replies gentlemen.

Tram

iTrader: (14)

How much do mail order tunes cost?

Websy21

iTrader: (34)

You would have to confirm with a sponsor I'd say it would vary b/w 200-300 but If I were getting it tuned somewhere I'd ask them if they would do it as a package deal. Especially if you bought a bunch of parts from them too.

Tram

iTrader: (14)

Wow.. That kinda blows.. 300 bucks just to drive to get it tuned again.. I guess I'll check with my tuner and see what he can do..

RE AND CHERYL

iTrader: (31)

Your tunner is gonna start by uploading a tune that is close for your set up and then fine tune it from there. MAybe if you send them our PCM they can upload a close tune so you can get it there.

Aside from dumping extra fuel which could foul the plugs or even wash out the rings if it's bad enough, It's impossible to tell what the results of driving it that far would be until you do it. At different parts of the fuel map you could be anything from too rich to dangerously lean. Keeping the larger injectors in will probably avoid the too lean thing but there is no way to tell.

If you do drive it, take plugs with you and change them before they start to tune it.

Re'

Tram

iTrader: (14)

I shot my tuner an e-mail.. So we'll see..

If not, I'll just get one of wait4meperformance.com's mail tunes and drive down..

Thanks guys.

Jeff

StevieZ

iTrader: (3)

Backfiring is a sign of too much air, not too much fuel. So is a high idle. Check to make sure there is no air leaking into the manifold. All hoses are hooked up properly?

The Alchemist

iTrader: (19)

I highly recommend against driving a car untuned for any amount of distance. Look at any of these threads about being down on power, burning oil, etc etc and a cause of a lot of them is driving untuned. One of the worst things you can do to a motor is swap out injectors and start the car untuned. You WILL wash out the cylinder bores and your rings will be toast. Look up the cost of towing the car to the shop, then look up the cost of replacing a set of rings, and rehoning a block, and you'll see it costs a lot less to have a car towed into a shop. Washing out the cylinder bores will result in poor compression, ring flutter, which leads to low horsepower and burning oil.

This isn't a time to go the cheap route, because it will cost you big time in the end.

You've got a couple options to do this right. See is someone close to you have HP tuners, efi live or ls1 edit and can come over and flash a new tune with the correct injector scaling. Or, see how much it will cost to get a mailorder flash. Or, finally, see how it will cost to have the car towed to the tuning shop.

Driving a car after swappings, heads, injectors, cams, is a bad idea and you're asking for trouble.