Hey all, I'm running a TA51 turbo with 42# injectors. My fuel pressure is static set at 50#. Car runs good, but leans out a lot. I'm not quite sure that I've got the best chip for the injectors. How do I know when I need to get bigger injectors, fuel pump or better chip? What kind of signals should I look for to determine which route to go. I'm only running 16# of boost and I get about 800 from the O2 sensor. My retard on my scanmaster reads sometimes as high as 19.9, so I'm thinking I need a bigger of something, but I'm not sure what. If you need more info on the car, let me know.
What fuel pump is in the car now? Is it hot-wired? From my limited experience, I think the fuel pressure is set awful high for only 16psi of boost. You need to make sure the fuel pressure is rising along with the boost. The basic rule of thumb is for instance; your fuel pressure is set at 50psi & the boost is set at 16psi, you should have 66psi fuel pressure at wot (50 + 16 = 66).
If indeed your fuel pressure is rising like it should, the knock retard is probably happening because you're TOO RICH. Turn the fuel pressure down to about 38-40 psi (line off) & take it for a spin. Just moniter the knock very closely! HTH
Thank's, I'll try that. It never really occured to me that you could get retard from too much fuel. I have a hot wire kit installed with a "high output fuel pump." It is an intank pump, but is about the best you can buy, supposedly. I think I paid about $200 for it.
Well, if anyone has any input, please jump in. I dropped the fuel pressure to 40#. I now am getting readings of like 4.0 degrees retard at about 3/4 throttle and I'm getting retardation that I can feel, ie - the car really falls on its face.
Whose chip are you using? The chip is setup to be used with those particular injectors correct?
If the fuel pressure is rising with the boost as mentioned above, then we can rule out the fueling system.
How long has the 51 turbo been on the car? If there is any oil in the manifold from a leaking turbo seal, it will kill octane & cause detonation.
Is the cat convertor still on the car?
The chip came with the injectors. It has no markings on it except a green dot.
The fuel pressure rises with boost just like it should.
The turbo has been on the car about 3 months. It was new when I bought it. My previous turbo smoked real bad, and it took me about 6 months to get the new turbo on - I'm poor
I cleaned out the whole intake system, intercooler and throttle body when I put the new turbo on. The cat is still on the car, but I have a 3" "low restriction" cat, with 3" downpipe and 2 3/4" exhaust.
Another thing...I increased my fuel pressure to 45# this morning for the drive into work, and I still get about 4-5 degrees retardation - and I can feel it. I'm beginning to wonder when my scanmaster gave me number like 17-19 degrees of retard, if it wasn't working correctly. The car seemed just fine when it was doing it, but I know those numbers aren't good, so I backed out of it. At any rate, I'll probably increase my fuel pressure up to 50# for the drive home, since that seems safe. Also, with my fuel pressure at 40#, my O2 was reading about 730-780. My O2s at 45# were about 800 - 820, but I was getting retardation of about 4degrees and it was retard that I could feel.