Daytona T/A

Ok, my car has been having some light spark knock when I lean on the gas and it if I floor it it makes like a rattling kind of sound. It gets better if I use premium and when the engine is warmed up. My owner's manual says that light spark knock is normal under acceleration and when going up hills and I using anything above 87 octane is not necessary. Also, the guy I bought it from said he always used midgrade because if he didn't the engine would knock a little. My question is, is what my engine doing normal??? It's an '83 Trans Am with a 305 w/crossfire injection. If it was just "light spark knock" and only when I used regular I wouldn't worry about it but the fact that it's still doing it when I use premium has me worried. If I do need to get it fixed how expensive is it going to be???

Daytona T/A

oh, yeah... my car only has 44,000 miles on it and the guy I bought it from is older and had it since it was a year old and the car's in great shape so I don't think it's been beat on...

THEGENERAL

try putting a full tune up on it and it should help ..i would also run the higher grade fuel whenever possible

Daytona T/A

I pretty much did... cap and rotor, plugs, fuel filter, thermostat, flex plate replace & they said they adjusted the timing when they did that... um.... I didn't do plug wires because I want MSD and I don't know where to get them... what else can I do???

ShiftyCapone

iTrader: (7)

You can get MSD stuff pretty much anywhere nawadays including autozone. I would check your timing. With the low mileage your car has I doubt you have any carbon deposits that are causing knock.

MrDude_1

i dont.

i would suspect carbon deposits.

RebelTillDeath3

Best thing to use to clean up carbon deposits in the intake is a 3 piece kit from Well-Worth. I used to think there's no way this crap actually makes a noticable difference. The other day at work someone brought in a newer V8 Ford pickup, it was missing so bad the whole truck shook and it did it in a constant pattern. The guy bought the intake clean. I though he's going to be pretty pissed after he spends $70 and it's still missing. I let the bottle run through the vacuum line for 30 minutes, drop it into reverse and it ran smooth as could be, I was shocked.

MrDude_1

water works equally well, and its cheaper too.

RebelTillDeath3

You'd let water run into a vacuum line for 30 minutes?

ShiftyCapone

iTrader: (7)

You can just squirt a little water into the TBI/carb from a mister just enough to make the car unhappy but not enough for hydralock. You should see black stuff come out the tail pipes. Might want to dissconnect the cat first.

Daytona T/A

Hey would there be black stuff coming out the tail pipes anyway? Cuz this winter I kept my car in the barn and every couple days I would go out and start it and after a few weeks I noticed two spots where there was kinda some black moist stuff...

Daytona T/A

This well-worth stuff... where can I get it??? and you just start the car up, dump it all in and let it run for 30 minutes???

RebelTillDeath3

Check around on the net, we have it where I work, but I haven't found it in stores. You pour the oil supplement in the oil, pour the gas supplement in the fuel tank.

To use the injection cleaner you'll need to rig something up. You have to pour the injector cleaner into a bottle that seals pretty good and with a valve at the top to control the flow. You should have a CLEAR vacuum hose or anything else that's fairly small (if you can't find a valve to rig up the flow of the bottle, go with a pretty small vacuum line). Hang the bottle somewhere on the hood so it sits above everything and the liquid easily flows down the line. Hook the line up to the vacuum line that goes to your brake booster. Let it run until the bottle is empty. Hook the vacuum line back to the brake booster and start revving the motor up. It will smell BAD, like burning food on a grill. White smoke should start coming out of the tailpipes, that would be the carbon buildup in your intake coming out.

This pic will give you the idea.....

It's called Pro Shock. Go to www.wellworthproducts.com

If you need any more help or an explanation that makes more sense just ask.

Red Devil

Water, ATF, sea foam, water/alcohol mix. Lots of stuff work that are cheap to expensive. Do a search for 'carbon AND deposits' and you will find some interesting things. I think my posted explanation of the why water works is still listed as well, but it's old. And IIRC some guy with a pop can hat actually listed two of sea foam's mixtures. And they work really well.

Red Devil

Most likely because it was cold and probably not moved. Those are the formings of carbon deposits from unburnt fuel/improper combustion.

Daytona T/A

um.... how about this... if I call the repair shop will they know what I'm talking about and do it for me??? I'm pretty good at one thing- F***ing things up- I'd feel better if a stranger did that to my car than me... did I just say that?

Red Devil

Unless you know the guy, probably not. If you are paranoid of screwing it up, go buy the sea foam. I would take the time and reach through the threads that come up in the search. All you need to do is hook it up to a vacuum line. If you are really paranoid about too much water get a spray bottle or use a larger amount of alky.

Daytona T/A

alright, thanks for all your help, guys. But do ya think I could check the timing first, tho???... just in case???...maybe??? ( Red Devil- yes, I'm very paranoid )

MrDude_1

no.

id spend about 5 mins doing it

and spend the other 25 watching TV or doing somthing equally unrelated.

DonP

Daytona T/A,

I don't know how you did your starting up through the winter months, but did you start it up and run the car long enough to hit operating temps? If not, I suggest you do so in the future. You need to heat the pipes up enough to burn the water condensation out, and to get the car out of open loop mode (if it applies). Also, if you don't run it long enough to heat up the cat(s), they will load up with unburnt fuel from running in rich startup mode, but not getting hot enough to burn off the unburn rich fuel.

Daytona T/A

I ran it about 10-15 mintues 2-3 time/week

Daytona T/A

ok, I've been searching through old forums and I read something about sea foam fouling the plugs... can anyone confirm this? I've got brand new plugs and I don't really want to have to crawl under my car and replace them or have them replaced... again.

Red Devil

Yea, if it's one of the formulations with oil in it. It will foul, but not as bad as if you used strait ATF. Water or water/alky is the preferance amongst a lot of us 'old school' guys.

RebelTillDeath3

Just find a Econo Lube n' Tune around you or someone else that carries Well Worth. I'm not trying to pedal products we sell. At first I thought it was a complete waste of money that didn't do anything, but after seeing the huge difference it made on that truck I did it to, I swear by it now.

Daytona T/A

too late... I just got back from NAPA with my shiney new can of sea foam. I'll try it this weekend. I'm thinking 1/3 vac. line 1/3 crankcase and 1/3 gas tank for now...

Red Devil

I wouldn't bother with any in the crankcase, and you'll probably see minimal gains in the tank. It contains water. I'd rather just dump in alky or any cheap FI cleaner for a tank before I change the fuel filter.

Daytona T/A

why, will it ruin the fuel filter or something? I just replaced that, too...