wierdbeard

i'm posting this for my pops, so i may not have all the info, if not please let me know what else is needed.
its a 3.5 liter VTEC 6 motor with a Garrett Turbo ( he said 3x4) currently residing in a hi-end sand rail.

the problem as explained to me, when he bought the SR it ran great, after a few months the turbo started cutting out, then stopped all together. after taking it to a honda guy (sorry don't know who or where) he was told the turbo was dusted, so he ordered a new Garrett turbo for the engine, it was installed still kept cutting out occasionally, he said he had it hooked up to a diagnostic and it wasn't throwing any codes, he said the O2 sensors have been changed as well, he also said that he checked a diaphram (not sure where he found it) and found two pinholes, that was replaced, it seems to run better. Now when under normal acceleration the turbo seems to run fine but if he applies max throttle it seems to hesitate and stutter, like its not getting enough fuel. The fuel filters have all been changed and he said that he did put a fuel pressure gauge on it to see what it was running at. his normal pressure is at 50 on the fuel line, no idea what its at when the turbo is on.

What should he check? i'm thinking it may be a sensor somewhere, or something is not adjusted correctly.

Does anyone know of a shop that would be knowledgeable on this problem in Bakersfield California? He really doesnt want to have to trailer it to LA.

thanks

HiProfile

He should check what we refer to as "the tune". That means that he should hook up a wideband oxygen sensor & controller to determine if it is indeed not getting enough fuel. The stock sensors don't do anything under full throttle, and can only see a very narrow range. He should also chekc the spark plugs (google will show how) to read them to tell if it is a fuel or ignition problem. Any idea what kind of computer is running the engine? AEM? Megasquirt?

In many cases, its either fuel, or for F.I. n00bs, the wrong plugs. The plugs usually want a gap around .028" for a turbo motor, and should be 1-3 steps colder than stock. If it was tuned on the rich side (like it should be), eventually the plugs will go bad and it will start stuttering.

Your dad should also be aware that Garrett turbos should use an oil restrictor for the oil feed to the turbo. Hondas make too much oil pressure, which will hurt the turbo's seals.


BTW pictures would help us out a lot. Its not as common for people to turbo the V6's, so tuning options for them are a little less mainstream, meaning sometimes the tuning sucks.