grrrr.... still problems with starting BP!

matt_fulghum · Post by **matt_fulghum** » February 27th, 2005, 9:29 pm

it idles when I start it, kinda... but it always sounds like it's gonna die

I dunno... I'll have to try running it for an extended period of time later, if I can... I get the same weirdness with the throttle... dunno what's up with that. One of the guys I've been talking to from clubprotege says I might be getting a loss of vacuum somewhere in the intake, which would cause it to not idle right.

I'll try some stuff... still gonna get the BP MAF though... adjusting the SOHC maf helped a little I think... it doesn't wanna die with so much gusto anymore

I'll have to hook up a cheapo air fuel guage to get some sort of ballpark idea of where things are when the car dies. I have a feeling things are going to rich and that's killing it. If so, I can check everything that would have to do with the fuel mixture.

I'll keep you all posted.

93SOHC · Post by **93SOHC** » February 27th, 2005, 10:20 pm

matt_fulghum wrote:well... here's the thing.... the car actually STARTS....

BUT!

it'll stall out after a little while. It smells rich afterwards. I'm gonna probe the O2 sensor tomorrow and adjust the MAF, see if that helps. I think it has to be the MAF because when I push the gas a little it causes the car to bog down a lot, probably because it richens the mixture. The TPS might have something to do with it, but it was working perfectly on the B6 before I moved it to the new engine (it's a BP TB)

The problem you are describing is identical to when my MAF on my sohc 1.6. Even if it was fine on your sohc, i'm guessing you need a different maf

matt_fulghum · Post by **matt_fulghum** » February 28th, 2005, 6:47 am

yeah I'm gonna pick up the BP maf after school today... wish me luck.

93SOHC · Post by **93SOHC** » February 28th, 2005, 12:41 pm

good luck

LongJohn · Post by **LongJohn** » February 28th, 2005, 2:59 pm

Yes, good luck.

For a point of reference, I'm using the stock MX-3 VAF (they aren't really MAFs per se).

When I first fired it up, it idled very smoothly, but it didn't have enough power to make it up the driveway. The timing was hugely retarded.

With the timing set fairly well (timing light against the cam gear markings), it idles smoothly, pulls hard, and is generally a load of fun to drive.

I'm still planning on getting an RX-7 VAF, and then tuning the VAF and the timing on a dyno, but that might be a while yet.

Note to atlanta: I can stomp my gas pedal, or nurse it along, or whatever else, and it behaves just fine. My BP came with injectors, so it is possible there is some flow difference, or some control difference.

Another note to atlanta: with my default wiring, the PRCV valve was mis wired. Check this carefully, and check for blink codes. After fixing this (and replacing the bad distributor I had), I have no blink codes at all. If your PRCV wiring is wrong, you might not have the correct fuel pressure. I don't know this for fact though. The PRCV valve connects to the pressure regulator, but I don't know what it does to the pressure.

matt_fulghum · Post by **matt_fulghum** » February 28th, 2005, 5:57 pm

well, I got the BP MAF, and it idled a little nicer, but it still dies after about a minute... groan... maybe it IS a timing problem.

On the intake gear, the I is supposed to point up and on the exhaust gear the E is supposed to point up at TDC right? I don't have any idea how to time a DOHC motor, so I'm kinda useless when it comes to talking about this

Tunes67 · Post by **Tunes67** » February 28th, 2005, 6:13 pm

Ok.. here is a old trick I use to do to determine TDC.. First.. Take out all the spark plugs.. next.. put a compression gauge on #1 cylinder. Crank the engine by hand.. as soon as the compression starts to go up in #1 cylinder.. Take off the compression gauge. Put a long screwdriver down into the cylinder and let it rest on top of the piston.. (Make sure the screwdriver does not bind and can move about freely.) Slowly crank the engine further by hand watching the screwdriver handle, it will slowly raise up and then stop when the piston reaches TDC. Now there is a slight amount of play while the piston is at the very top (This is the crank continuing to rotate under the piston before the piston starts to go back down.) When your # 1 piston is at TDC on the compression stroke, Your cam timing marks should line up and you should find that your rotor in your distributor cap is pointing at #1 plug tower. If everything doesnt line up.. well something got hosed somewhere..

Tunes67

matt_fulghum · Post by **matt_fulghum** » February 28th, 2005, 6:28 pm

yes but what marks should line up? should both pulleys have I pointing up? or should the intake say I and the exhaust E?

Tunes67 · Post by **Tunes67** » February 28th, 2005, 6:48 pm

There should be a mark on the cam gear itself (both of them) And there should be a mark on the head casting or on the valve cover where these marks are supposed to line up. Sorry I cant be more specific than this.. I have yet to even see a BP or BPT engine. Assuming that Mazda followed a similar standard.. these marks would be how I find them on my B6. Hope this helps.

Tunes67

matt_fulghum · Post by **matt_fulghum** » February 28th, 2005, 7:19 pm

hmmm... well, one of the guys from clubprotege thinks that it might be that my engine's being starved of fuel, which would explain why it's fine for a little while, then dies, because the pressure might be dropping off or something... I'm gonna try putting a tube from the IM directly to the FPR and see if that fixes it... maybe the solenoid's bad? I kinda doubt it, but it's worth a try.

93SOHC · Post by **93SOHC** » April 21st, 2005, 12:06 pm

Been quite awhile since we heard if this thing ever got running, any updates Matt????

johnboi85 · Post by **johnboi85** » April 23rd, 2005, 12:11 am

he usually posts on clubprotege forums. so far he is having problems with his trans not going back on his motor.