Bad Gas?

TTA855

White lightning drinker
#1
I went to the drags last Friday, and on the way picked up a couple of gallons of 100 octane unleaded at a local gas station. The station's barrel was almost empty, so I got the dregs. On the way to the track, it didn't seem to be running at full power. At the track, it was definitely down on power, and on the second pass, about halfway down the track the engine bucked pretty severely. A visual inspection of the engine bay and underneath the car showed nothing obviously wrong. On the way home, it was hesitating under partial throttle. My guess is I got bad gas. Anyone have any other ideas?

I need advice on what I should do now (I have a little less than 1/2 tank left). Siphon the tank? Burn the gas out by driving it? Fill it up with fresh gas? Thanks.
 

michbc3

Well-Known Member
#6
It sounds like you don't have a knock gauge. Highly suggest that you use one if you are going to be playing around at the track.

I had a similar experience not long ago. I took the car to the track with a mild mix of high octane and 93 and in 2nd gear the knock gauge lit up into the yellow using my normal "street" tune at 17 psi. In 3rd gear the gauge went red, so I let off. I pulled 4 degrees of timing out and cut boost 2 psi. Knock was "quieted" on the next run, but of course I lost power. That was enough "fun" for the night.

Cruising around easy, I ran that gas out of the tank over time. After a fresh tank of 93 octane (at a Mobil gas station), the car was back to great performance with the timing and boost jacked up again. I am positive that the gas station (RaceTrak) did a switcheroo and sold me less octane than 93. Most consumers won't notice and that's 30 to 50 cents per gallon that they can pocket... Obviously I don't go there any more.
 

michbc3

Well-Known Member
#7
I think it's kind of remarkable that the octane that I got at RaceTrak was so low that it still wasn't enough even when I added 2 gallons of 110. Obviously all RaceTrak gas stations don't play games like that, so I don't want to slam the chain.

I guess bottom line is: get a knock gauge so that you can see problems coming on, not just feel them when it's too late.
 

Lsttype

Well-Known Member
#10
And just how do you drain the tank on these cars??? On our turbo Buicks, you simply unplug the hood light wire and connect to the grey jumper wire close to the alternator. Doesn't appear to be a grey wire on my tta. No hood light either:(
 

michbc3

Well-Known Member
#11
And just how do you drain the tank on these cars??? On our turbo Buicks, you simply unplug the hood light wire and connect to the grey jumper wire close to the alternator. Doesn't appear to be a grey wire on my tta. No hood light either:(
There may be a simpler way to do it that somebody figured out, but on my car, I'd unplug the fuel pump relay under the hood that is mounted on the cowl on the driver's side and jumper the correct pins on the relay socket to run the pump. I copied the remote fuel pump relay "hotwire" kit that they make, so making large hi-amp sparks under the hood wouldn't be a problem on my car. Even so, if I did this regularly, instead of jumpering the relay socket with a short wire, I'd make up some short wires with a switch to make it a little safer. I'm not a frequent racer and don't use a lot of boost, so don't regularly need to drain the tank to change or insure the absolute quality of the fuel mix. But of course many others do.
 

michbc3

Well-Known Member
#12
That's OK. Let me know if you find one!
Try calling Autometer directly to see if they still make them. Summit has lots of Autometer gauge pods, but I couldn't find one for 89 Camaros or Firebirds. I looked in my car files for an old (9 years now) receipt for the one that I have, but couldn't find it.
 

TTA855

White lightning drinker
#13
My mechanic fixed my TTA yesterday. He couldn't siphon the tank because of some kind of check valve, so he hooked a car battery to the fuel pump (255 lph) and drained the tank that way. He also installed a new Wix fuel filter I gave him (btw, he said Napa Gold is the same thing for less money). It runs great again!
 
Top Bottom