1g gsx Lean under boost

[topekagsx]

So i have a 93 eclipse gsx, with 6 bolt swap and 16g turbo at stock psi and 190lph walbro fuel pump, all done before i got the car. For some reason if I go over 5psi of boost I go lean to the point my afr gauge goes solid red the car spuders and won't go. I put in some 650cc injectors I bought and it did not help at all. Does it just need a tune or could it be something else?

 

[SmoochDarling]

With your current setup, if anything you should be running very rich. I would highly recommend rechecking everything on your car and verifying everything is infact what the previous owner has claimed. Also some engine management is recommended if your going to be messing around with fuel/air mixes.

 

[1995gsx20g]

650's with out anyway to control them makes a perfectly running car run like dog s...

the lean/rich gauge is garbage, i would get a real wideband.

the sputtering you are talking about is a misfire under boost. a misfire will make an o2 sensor read lean.

first off put the 450s back in if you have no way of controlling the 650s .
second i would check my ignition system. plugs, wires, coil. spray water on the wires and coil while its running and it will show you if you have any exposed wires or coil.

what kind of plugs are in the car?

 

[Clinical]

get a real wideband and as mentioned verify that you even have the pump/injectors - you also should look into an FPR

 

[topekagsx]

I have an afpr kit i bought from slowboyz and safc II waiting to go on the car...I wanted to get it running right 1st...It has stock plugs in it...I have a real wideband I can hook up I just gotta pull it out of my other car...also wouldn't a misfire cause a rich reading since the fuel would remain unburned?

 

[steve]

Make sure that the existing FPR is getting a good reference from the FPS or intake manifold. If the fuel pressure isn't tracking manifold pressure you'll get less and less fuel as boost rises.

 

[krusty_9]

If you need any help, I know my way around DSMs fairly well and don't live too far away. Just send me a PM.

Also, it sounds like steve may be on to something, and with the very few mods your car has, there is no need for an aftermarket AFPR. Sell that and the SAFC and get DSMlink

 

[topekagsx]

ok i'll check my ignition and the fpr sometime this week and post up what I find.

also how would i go about checking the fpr? Just make sure that the vac line has good connection and isn't pluged up with anything?

 

[steve]

how would i go about checking the fpr? Just make sure that the vac line has good connection and isn't pluged up with anything?

Without a fuel pressure gauge that's about all you can do.
With one you can connect vacuum and pressure sources and verify that the fuel pressure changes 1:1 with the what you apply to the reference port.

 

[topekagsx]

ok thanks I will clean those out and check them over

 

[1995gsx20g]

also wouldn't a misfire cause a rich reading since the fuel would remain unburned?

In reality it would but to your o2 sensor that only sees oxygen it sees an excess of unused oxygen when the engine misfires.

If you have been running around 15psi in the past your plugs could be shot. try one step colder, ngk bpr7es(stock number 5534) is what most people on this forum use

 

[topekagsx]

I cleaned the lines, checked the wires and still nothing...Should I try to hook up my adjustable fuel pressure regulator since it has a fuel pressure gauge on it?