Jump to content
SAU Community

Recommended Posts

A low compression result = engine build time, it is the only real fix. It could be just a top end, but more like a complete build.

You need to get your mechanic to check it out and find the reason, could be that a dyno run will help pinpoint it.

I'd be surprised if its a compression problem, you would see things like oil burn, oil in the radiator, chooffing black and/or blue smoke everywhere, hard start from cold and etc etc etc

For mods etc check the dyno thread.........but nothing comes cheap = if you want more power you will need more $$$$$

first thing you need to do is get a compression test done, after that you can think of other things, a compression test is the easiest thing to try atm.

If you have a standard ecu and only 4 psi increase it should still be fine, i was running 15 psi on a standard ecu and it wasnt running badly.

ok cheers brett thanks ... how much is a comp test ? can any mechanic do it

also the question bout the boosting was directed at whether that says anything about compressin

Edited by havoc_r33gtst

dont know how much, depends on how much they charge per hour, any mechanic should be able to do it, best of finding one that has experience with skylines as it will help with other things in the future.

if ur compression is low it could be stuffed rings, valves, head gasket etc.. im having trouble with mine too when i turned the boost up it seemed like it made no difference and i heard a whistling sound on boost then i realised i have a boost leak on from my intercooler hoses on the front so hopefully longer hoses will fix it and hopefully ur car gets sorted soon

You are definately having issues due to NO ECU/TUNE.

Fact is one car might be fine @ 100psi, the next will get angry @ 10psi.

This is what your car is doing, simple as that.

Get some proper engine management going on, or back off the boost.

$550 for boost t and dyno?! :D

check basics, could be fuel pump too, hope the previous guys at least checked afrs

33gtst always freak out when u boost em up with light mods on stock computer

take it someone who knows these things, diagnosis on a dyno shouldnt take long :cool:

wow i think you got raped on the boost tee install and power run.... it was in no way a dyno tune anyway as i said before with my mods i made that power but if i run anything over 9psi i will drop mass amounts of power and i did up it to 11psi and made 140ish put it back to 9 and then it was back to normal.

try turning the boost down on boost controller to 8-10 see if that makes a difference then go over all your intercooler piping make sure you dont have a boost leak anywhere.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Depending on how long the car sat it is very possible for injectors to be stuck open or closed, I'd get them cleaned and flow tested. Other than that, obviously when the loom changes and the car doesn't start any more....the loom is suspect so some tracing / comparing may be required
    • Harness is for a s1 Rb25det, and it is engine and lower harness.  the old harness had broken off plugs and was in very rough condition/exposed wires and splices etc. it is not able to be put back on the car, I could visually inspect to see if they had rewired any pins on the ecu plug. The fuel pump definitly isn’t turning off it’s an external pump and very loud you can hear it. Will look at the other harness tonight, am also going to pull the fuel rail and watch the injectors spray, will update here with what I find. Pretty sure at this point it has to be something to do with injectors because car will fire up on starting fluid and cas is clicking the Injectors. Fuel pressure is steady 43psi 
    • Check the injectors flow evenly, and are actually flowing what you and the ECU think they should be flowing. If it's starting up on starter fluid, you have a fuel issue. Is it possible under cranking your fuel pump is turning off?   The harness you replaced, is that the whole engine harness? Do yourself a test, and drop the old harness on and plug it into the Z32 ECU. It's possible they've wired things different. From memory S1 to S2 is different in RB25 and you may have a wrong loom
    • I haven’t pulled the injectors to watch them spray yet but they are clicking from the cas and all of the spark plugs are wet with fuel. I’ve thought the cylinders were being flooded from the beginning and was hoping fuel pressure would fix it. Tonight I am going to pull the rail and watch the injectors spray. Don’t know how to test/diagnose if the plugs are firing in correct sequence but that should be a timing thing and as far as timing goes my car still has the half moon for the cas can only install it 1 way. And my mechanical timing is 100% correct I posted photos above. Confirmed with the balancer on and off. 
×
×
  • Create New...