rb20det problem!!!

[mikalkouki]

i can't find out what the problem is with my rb20det s14!!!! It starts and idles just fine, but when you try to give it and throttle it stumbles really bad. If you very lightly apply throttle it will slowly reach higher rpm's arounk 6k, but stumbles on and off while getting there. Any sudden throttle bogs the engine almost to the point of shutting off. I've tested the maf on another vehicle works great. Tested the ecu on another vehicle... works great. Same goes for the ignitor chip and CAS. Fuel pump is spraying plenty of fuel when plugs are removed.... What could possibly be the problem????

I do have a z32 maf with an safc tuned to -27 across the board and the sensor no. is set at 2in 6out...... but like i said, idles awesome. problems occur above 2k

[Eikon]

Boost leak?

[shinaka]

The Z32 MAf would already be putting out a lower voltage than the stock MAF.....why would you lower the voltage by 27%...weren't you supposed to increase the signal rather than lower it?..Are you using the stock ECU?

[lyon23]

i can't find out what the problem is with my rb20det s14!!!! It starts and idles just fine, but when you try to give it and throttle it stumbles really bad. If you very lightly apply throttle it will slowly reach higher rpm's arounk 6k, but stumbles on and off while getting there. Any sudden throttle bogs the engine almost to the point of shutting off. I've tested the maf on another vehicle works great. Tested the ecu on another vehicle... works great. Same goes for the ignitor chip and CAS. Fuel pump is spraying plenty of fuel when plugs are removed.... What could possibly be the problem????

I do have a z32 maf with an safc tuned to -27 across the board and the sensor no. is set at 2in 6out...... but like i said, idles awesome. problems occur above 2k

The settings on your safc are wrong it should be 2 in 4 out, and if you have stock injectors the adjustment sould stay at zero. I'm in jax too send me an email if you wanna get together.. not many rb's here in jax that I don't know of or havent done some [email protected]

[mikalkouki]

yes i am using the stock ecu and i've tried running the afc at 0 across the board that was my first attempt.... maybe it is a boost leak, i'm gonna check for that tomorrow. lyons23 i shot u an e-mail!

[mikalkouki]

had to be something set up wrong in the afc maybe the dec. air settings..... initialized all settings and runs a helluva lot better, however it still sputters a bit under acceleration and backfires after throttle is released. also when it's in drive there is almost no power! push the throttle to the floor and it won't even spin the tires in grass???

[lyon23]

had to be something set up wrong in the afc maybe the dec. air settings..... initialized all settings and runs a helluva lot better, however it still sputters a bit under acceleration and backfires after throttle is released. also when it's in drive there is almost no power! push the throttle to the floor and it won't even spin the tires in grass???

yeah it sounds like a boost leak.. replied to your email

[Sil240]

http://forums.racebread.com/index.php?topic=636.0

[Vkoslak]

I just fixed this on my car. I had the gap set wrong and I was using cheap arsed plugs.

Now I'm using some iridiums and I used a measuring caliper to get the right gap.

I had already replaced igniter and some coil packs. Guess that means I got more extra parts now though. lol

[mikalkouki]

I just fixed this on my car. I had the gap set wrong and I was using cheap arsed plugs.

Now I'm using some iridiums and I used a measuring caliper to get the right gap.

I had already replaced igniter and some coil packs. Guess that means I got more extra parts now though. lol

yeah, unfortunately I did the same thing ( Iridiums @ .70) and the problem still persists....... I just got a wideband o2 sensor and I'm about to be fine tuning it to make sure of the afr, but I really don't know why it would be running so rich

BTW.. just got the fpr on and it's running 35 psi w/ vac. and the tps is spot on .48v closed 4.9v WOT... so thats ruled out

[Vkoslak]

You know, I had a z32 maf I got off ebay that would work fine in my 300zx, but would cause my rb to run really rich. So I took the one from my 300zx and ran it on the rb and it worked fine. The stickers were slightly different, but all the numbers were the same. If its possible, find someone with a 300zx and have them let you try their maf.

When you rewired your maf, did you shield it and ground it at one end? I did some ghetto shielding with aluminum foil, speaker wire, and electrical tape.

[mikalkouki]

You know, I had a z32 maf I got off ebay that would work fine in my 300zx, but would cause my rb to run really rich. So I took the one from my 300zx and ran it on the rb and it worked fine. The stickers were slightly different, but all the numbers were the same. If its possible, find someone with a 300zx and have them let you try their maf.

When you rewired your maf, did you shield it and ground it at one end? I did some ghetto shielding with aluminum foil, speaker wire, and electrical tape.

actually i was wondering of not shielding the maf wires for that small section would cause this problem... how did you shield yours? connect the speaker wire to the shield wire and run it around the wire foil the speaker wire and electric tape it up?

[Vkoslak]

Just wrap the mafs wires with alum foil, then use the speaker wire to ground one end of it, then wrap with electrical tape so it doesn't ground out anywhere else.

[mikalkouki]

ok.... so this is the story now..... shielded the maf wires, grounded the neutral safety switch (not sure if that was really necessary), and hooked up the boost gauge. Now the car runs a helluva lot better and under drive pulls almost 10psi of boost.... so no boost leak i'm pretty sure. However it still backfires every so often, especially under wot or at high revs at idle. The bov opens, but under idle revs (unless it's violent throttle application) it doesn't open and I get alotta compressor surge. Is that normal with the Type -H RFL? Also I tried to adjust the tach with the screw on the back and it seems like no matter how I adjust it the damn thing either doesn't move at all or moves up to 1k and drops back down and bounces. All the help is much appreciated!!! Hopefully I'll have this thing on the road b4 too long!!!!

[mikalkouki]

bump