loss of power

[primera4life]

Well I had this problem for awhile now, I have a turbo g20, The problem is when I start my car is starts up good, then when I start to drive, the car shakes like it wants to cut off but it don't. I press on the gas and it bogs and I hear popping noise coming from the air filter, then all of sudden it shoots and go, then it happens again loss of power and then moves, but after like 10 mins of driving the problem goes away. I hear the boost build up when it starts to bogs, I just recently changed my spark plugs wires,cap and rotor and I found that I had oil on the spark plug threads not on the tip. Only in one cylinder. Then the car backfires alot. I bought the car turboed, and the owner before me said it has a jwt ecu. Maybe I should get my car tuned, No check engine light is on, or who knows he probably took out the bulb. Any ideas?

[Black95G20]

check for a boost leak. otherwise you might need a new tune.

oil on the spark plug threads is probably a leak from the valvecover gasket.

[JPC94G20t]

Almost positive your problem is tune related. When was the last time the plugs and wires were looked at?

[primera4life]

Yesterday I changed the plugs, and wires, Last time I scanned my car I think I remember I saw a knock sensor code,egr code, and crank sensor position code. I have a u13 sr20det in there. I had platinum plugs in there, with .44 gap, now i have copper plugs in there with .35 gap and the idle is not above 1100 rpm anymore when it warms up.

[diptenkrom]

how about grounding, have you checked to make sure there is not a loose connector?

[primera4life]

I checked my grounds They all seem fine.

[primera4life]

What is the cheapest way too tune my car?

[primera4life]

I will change the sensors and see whats happens.

[thefultonhow]

The backfiring probably means you are running rich... either the tune is wrong or there is a problem with one of the injectors.

[primera4life]

Isnt the jwt ecu suppose to be a little on the rich side.

[thefultonhow]

Not rich enough for you to be backfiring, I don't think.

[Grimsta]

Well the thing is the problem eventually goes away, that sways me toward NOT tune related.
Let me ask, do you get in the car, start it up and just drive off hard? If so you will want to let the turbo warm up 1 or 2 minutes, then see if it still does this.
Anothing thing to check would be the O2 sensor. In my former S13 we had a bad O2, replaced it with an AEM UEGO and it ran like a champ. I have those available for $238.50.

Also, has it always done that since you bought it? You mentioned you bought it already turbo. Remove the turbo intake and inspect the compressor blade. Make sure there isnt any debris blocking its path or the blades arent bent. <== That was a problem on the Supra

[Robj80]

By any chance is your front O2 spliced? I had similar drivability issues. When my car was cold it would bog and sputter. I changed out my front O2 with a longer 300zx one. No more spliced wires and the car loved me for it!

[primera4life]

This only happens when the car warms up, if its cold and I take off its fine, then when it warms up it starts. Then it eventually stops, untill I shut off the car and start it again.

[Grimsta]

when I start my car is starts up good, then when I start to drive, the car shakes like it wants to cut off but it don't. I press on the gas and it bogs

but after like 10 mins of driving the problem goes away.

Then you say it runs cold fine and warm not, which one is it? After 10 minutes of driving the car is fully warmed up. Its not actually "warmed up" if you let it run for 2 minutes then go, but you should do that to get the oil circulating for your turbo.
Anyways, does this thing blow much smoke out the tail pipe when gassed? Still kinda sounds like an O2, possibly MAF

[Deez]

If you have a bad crankshaft position sensor the ecu will run in "limp mode", but that code should be triggering your cel?