I had my Jet hot LT's installed a few weeks ago but havent driven the car much because of a small leak, here is my problem. I drove it around a little last night and when im at low speeds (10-15 miles an hours) i will hit the gas and my car just does nothing for 2-3 seconds. Its like im not even pushing the pedal then it revs and goes. Any ideas on this guys? all i have done is the LT's but here is a list of all my new parts. Opti less than 5000 miles, plugs wires new, fuel pump and filter new, coil and ICM new, ignition switch new. I didnt notice this happening untill after i put in the LT4 knock mod. but i dont think this would have anything to do with it. the car is a 94 a4 and the trans has been rebuilt as well, thanks for any help !

 

damn where is all the techs todau

 

You said it started after you put the LT4 knock module. You could try swapping back to the LT1 knock module to see if anything changes. Did you use o2 extensions? Have you had your TB off recently? Troubleshooting sucks...good luck man.

 

yes i have the o2 extensions and i have not had the TB off ever

 

Your best bet is to try to get a hold of a scanner that can read real time data and log it. You'll want to see what sensors are doing what when this problem is occurring.

 

yea i will hook up the data master tonite and post the results tomorrow and see what you think since i have no idea what im looking at or for

 

The TPS is cheap so i will buy one tonite and see if that helps

 

OK now i have a beef with some of the peoples advise with tunes on just header only cars, i replaced the TPS last night and then went out for a drive nothing changed. i noticed the temp was getting higher than normal so i put the 160 thermo back in and then pulled out my hypertech. yes i know its not all that great but i forgot i had uninstalled it before i took it to the shop. well installed it back on and got all my throttle response back and no More hesitation. so i going to say you do need a tune with just LT install

 

I may be totally wrong, but seeing as how a thermostat is not going to affect your throttle response at all, I am guessing that your intake elbow wasn't sealed properly. And when you reinstalled it after the t-stat swap, it sealed and you no longer have an air leak which gave you back your throttle response.

As for a tune, you could pick up 10rwhp from a tune on a bolt-on LT1.

 

the elbow was on right it was not leaking i had already checked that because it was an issue i had before. i changed the thermo back because of the temp going higher than normal, i put the 180 in during the very short winter we have here

 

sorry i went back and read my post sorry, as in hyper tech i meant the tuner

 

So you are saying that without your Hypertech tune, you have a 2-3 second delay in throttle response?

 

yes, i would hit the gas and just get nothing

 

like it was starving for fuel

 

Just doing a header swap should not cause the car to be starved for fuel.

 

imo 4 biggest problems that occur after lt swap

1) burnt plug wires
2) cracked ceramic in spark plug
3) bad o2 wiring from extensions
4) fouled o2's from coating burning off and getting on them

 

im no expert but wouldn't moving more air threw it require more fuel as well ?

 

checked all those first but putting the hypertech yune back on the car fixed it
i changed plugs and wires during install and i got the headers used so the coating was already burnt off

 

Yes, but your computer will use the o2 readings to adjust your A/F ratios accordingly and supply more fuel. The stock fuel system is more than capable of supporting a full bolt-on application.
Besides that, I wouldn't mess with that Hypertech and I'd get a real tune.

 

im going to be getting my LE package ordered soon and then will get a real tune, for now the hypertech can keep me on the road. i bought tuner cats tune a while back but when i went to use it i got scared lol