Ian C Posted April 4, 2004 Share Posted April 4, 2004 What's the stock base fuel pressure supposed to be? -Ian Quote Link to comment Share on other sites More sharing options...
veilsideTT Posted April 4, 2004 Share Posted April 4, 2004 From my toyota workshop manual Fuel Pressure: 226 - 275 kPa (2.3 - 2.8kgf/cm2, 33 - 40psi) Hope this helps Scott Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted April 4, 2004 Share Posted April 4, 2004 38.5 psi Quote Link to comment Share on other sites More sharing options...
dude Posted April 4, 2004 Share Posted April 4, 2004 Originally posted by Terry S 38.5 psi hello stranger !!!!!! dude:flame Dev Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted April 4, 2004 Share Posted April 4, 2004 Mate I'll call you in the morning, been running around trying to buy silly French cars all day:( Quote Link to comment Share on other sites More sharing options...
dude Posted April 4, 2004 Share Posted April 4, 2004 French !!!! youve really lost the plot this time !!! Dude:flame Dev Quote Link to comment Share on other sites More sharing options...
Ian C Posted April 4, 2004 Author Share Posted April 4, 2004 I've got something from Darren Blake that appears to be an official Toyota document on testing things engine-related. One of these bits says I should have: 24-31 psi with vacuum at idle 33-40 psi without vacuum at idle Now, I'm assuming that "with vacuum" means with the vac hose on the pressure regulator. That's lower than what anyone has said yet. Regardless - here is me with 49psi. Hmmmm. Best I get that checked again before I leap to conclusions. -Ian Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted April 5, 2004 Share Posted April 5, 2004 31 is horribly low. Mine stock was 38. I am gonna get some stock injectors flow tested next week. I will ask to see what the spray pattern is like at 31 psi but I doubt it's good. Quote Link to comment Share on other sites More sharing options...
Adam W Posted April 5, 2004 Share Posted April 5, 2004 You're supposed to set FP with the vac line disconnected, the regulator drags the pressure down at idle because the intake is under vacuum, so the pressure differential (and spray pattern) at idle is still ~40psi (or whatever you set it to with the vac line off) the same as it is when you're at 18psi and the regulator pushes the FP up to 58psi. It's meant to be more accurate setting the FP with no vac line because different 2JZ's will draw slightly different amounts of vacuum depending on cams, wear, leaks etc Quote Link to comment Share on other sites More sharing options...
Ian C Posted April 5, 2004 Author Share Posted April 5, 2004 Nonetheless, my fuel pressure is about 10psi higher than the highest of these figures, could this be causing my overfuelling or is it just an artifact of the walbro pump? -Ian Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted April 5, 2004 Share Posted April 5, 2004 AFAIK there are 2 types of Walbro. The 341 & 342. The 341 is the one suitable for the Supra as it has a static pressure of 38.5 psi. The 342 is for EVO's etc with a pressure of 43.5 psi. Either way I would have expected your narrow band to compensate for the higher pressure. Have you tried another FPR? Quote Link to comment Share on other sites More sharing options...
Dragonball Posted April 5, 2004 Share Posted April 5, 2004 Originally posted by Ian C Nonetheless, my fuel pressure is about 10psi higher than the highest of these figures, could this be causing my overfuelling or is it just an artifact of the walbro pump? -Ian No harm in leaning it down to 32psi at idle (oops sorry!) and seeing what the effect is? Mine is down at 2.2 BAR (x14.5=32psi) at idle and wacks up under throttle Another variable taken out then! Quote Link to comment Share on other sites More sharing options...
Ian C Posted April 5, 2004 Author Share Posted April 5, 2004 It's a stock non-adjustable FPR, so I can't change it, and yes I've tried another one. I bypassed the whole tank return system with new fuel hose attached to the FPR outlet and feeding into a petrol can, and that didn't make any difference, so I don't think there is a blockage there, but surely for artificially high fuel pressure that's where you'd need the restriction?! -Ian Quote Link to comment Share on other sites More sharing options...
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