Prelude WILL NOT BOOST?! afc?
 

Ok, Setup is 97 prelude OBD2
SAFC v2
dsm 450cc injectors w/ 10watt-10ohm resistors.
t3/to4e turbo w/ 5lbs wastegate.


Heres the problem...
Car idles and runs fine... i took the fuel out to around -40 to -36 across the board high and low for all the settings.
I'm positive there are no boost leaks.

Is the AFC not compatible with OBD2 ecu's?!

THe car runs, i can hear the turbo spool and all that.

It runs just like N/A to about 1500-2000rpm... then it just goes like a pooch the rest of the way... there is no boosting... guage reads 0 vaccuum.

BY THE WAY>>> I have everything mechanically hooked up correctly. I'm not a noob at this. Go to turbod16.com, i'm 95turbohonda over there.

I'm to the conclution that theres something wrong w/ the AFC and OBD2.

Any Ideas???

Re: Prelude WILL NOT BOOST?! afc?
 

um, yea theres something wrong... U need some sort of engine management besides the afc. I'm not the site expert but I do know that your map sensor dont like the boost it sees without computer work (ie uberdata, chrome, etc..) Even the greddy piggyback controller... somethin man. do more research on it.

Re: Prelude WILL NOT BOOST?! afc?
 

^ hey brotha... i know my research...

The afc IS ENGINE MANAGEMENT... it's better than an FMU an ----, but not the best out there... You dont run Crome/uber etc WITH an afc!!!! :o

I ran the Safc v2 on my 95 OBD1 d16 with a Gm 3bar, and ran 14psi all day long. No Problems.

... well, anyone else have an idea?

Re: Prelude WILL NOT BOOST?! afc?
 

ha okay dude, have fun blowin it up.

Re: Prelude WILL NOT BOOST?! afc?
 

One thing that I am thinking though, if the turbo is spooling why would the boost gauge read no boost? Surely even if AFC is at fault, the pressure should still be there because the turbo is spooling and if there is no boost leak, anyone? I am no expert but just one thing I had on my mind.

Re: Prelude WILL NOT BOOST?! afc?
 

sounds like a boost leak or a vacuum leak thats letting most of the boost out

Re: Prelude WILL NOT BOOST?! afc?
 

Ya check all the couplers, make sure they are tied down TIGHT!

Re: Prelude WILL NOT BOOST?! afc?
 

the VAFC has NOTHING to do with whether or not the car is going to make boost. If your not making boost you have a leak some where. If its internally gated make sure that its closed. The VAFC only controls fuel and the only affect it has is how well the motor takes the boost it recieves.

Re: Prelude WILL NOT BOOST?! afc?
 

arent prelude injectors 345cc?
u may be a tad lean at -36.
How did u figure out those numbers? The write up in the EM section is for 240cc injectors.

Re: Prelude WILL NOT BOOST?! afc?
 

Stock prelude injectors are 270cc

There are no boost leaks at all...

It's externally wastegated w/ 38mm gate.

Doesn't overheat or anything like it would if it was too lean... and no excessive black smoke as if it were rich.

I wired the AFC correctly... i've done it many times before, and checked the wiring graphs and Hanes Manual.




I've narrowed the problem down to this...

Just as the car SHOULD enter boost... it bogs down to the feel of N/A. The car is retarding ignition or cutting fuel. One or the other, or both. I had all the exact same setup on my civic. (my civic is pulled apart for tranny re-build, Head re-build, and CromePro swap for 350whp sohc)

Background info: the injectors came out of my car, the clips and resistors came out of my car, the AFC came out of my car, and his Setup is the same as mine (SSAC kit) ... SSAC is my sponsor, and sends me alot of free ----, he uses pics of my car on his ebay auctions... but besides that... back to the problem.

I'm stumped. It has to be something w/ the stock ECU or Map sensor. I tried unplugging the Map sensor too, and same results, except idle was screwed up (as anyone who knows about hondas would know what happens)


Is this a preludes' LIMP MODE???


Question: What is up with OBD2 ecu's, Stock map sensors, SAFC's and such? Anyone know a turbo prelude w/ OBD2 ecu with the AFC setup? They are rare, cuz there's alot of space issues, but i made it work for the kid w/ my amazing plasma cutting skills ^-^ ;)

Re: Prelude WILL NOT BOOST?! afc?
 

CEL light on?

Re: Prelude WILL NOT BOOST?! afc?
 

nope.

Re: Prelude WILL NOT BOOST?! afc?
 

You have a knock sensor, since you are using an SAFC and it doesnt sound like you have taken ignition timing into effect, it is probably detonating like a mofo, and you are pulling a TON of timing..

just a possibility..

Re: Prelude WILL NOT BOOST?! afc?
 

ya, it's my buddies car... he doesnt really know anything about turbo's, so i'm helpin him out... but this one's makin me feel :1

I wired up the knocking sensor in the AFC also... and it's not reading any knock at all... i'm not hearing it either... So, idk what's up... I guess no-body here knows.

Re: Prelude WILL NOT BOOST?! afc?
 

maybe ur bov is fubared. and double check ur clamps no matter if ur right or wrong. ur car shoukd get SOME sort of boost, even if a coupler was hanging on for dear life, u should see atleast 1 lb of boost.i think its mechanical, not electrical, theres is nothing electrical stopping a turbo from spinning when more and more exhaust is being pushed passed it.

Re: Prelude WILL NOT BOOST?! afc?
 

Your BOV or Wastegate could be fucked. Check if they work right, wastegate might be open all the time and/or vaccum might be fucked up.

Re: Prelude WILL NOT BOOST?! afc?
 

It's not your afc...if your afc was throwing the car into limp mode due to the map sensor letting the ecu see positive pressure, then you would pop a cel. Most boosted obd2 cars i see usually run off an afc or something similar like a greddy blue box. It def. does sound like something mechanical.

Re: Prelude WILL NOT BOOST?! afc?
 

my car did this same thing with a bad tps ... id floor it and it'd build like 3 psi hit 4k or so then fall on its face and make no boost ... and it wasnt throwin a cel .. also check the pluds and see what there like

Re: Prelude WILL NOT BOOST?! afc?
 

Possibly the wastegate. check all of the fuel and ignition systems, a bad ignition coil will cause problems like this making it bogg out. Wire plugs and dizzy too.