Car starts and drives up 2000-3000 rpm then stutters and dies-vaccum line?

[leesredgt]

okay i have an 92 240sx with a rb25det in just got it runnin last sunday the car idles fine and revs up smooth but when i go to drive it and im just drivin it easy not really any load on it just pullin out of my drive way as soon as it hits close to the 2000-3000 rpm range or about 25-35 mph and somtimes not even that it starts to sputter and cut out realy bad so i have to keep the rpms up and the finally it dies but it will start right back up and then it will do it again i turned my solinoid off on my avc-r and i let the wastegate regulate the boost and it dosent change i know im getting fuel and spark so this leads my to think and maybe im wrong, that its a vaccum line i hooked up wrong. heres some pics of the lines that i hooked up...tell me what ive done wrong.

the top line i ran to the boost solinoid and then took the bottom line to the canister.

here i have the fuel vapor line into the canister and that bottom line and then i have the other hole plugged.

heres the boost solinoid and the line that i ran from the top metal line to it and then to the wastgate.

this is the only line that i wasnt fo sure of its the line coming off the black tubing right next to the valve cover so i just plugged it off.

and this is just a pic of how the whole swap turned out.

okay thanks in advance guys i need to get this fixed i havent even got out of third yet.
Modified by leesredgt at 4:46 PM 11/13/2007

[S13 240SX]

hey man i was having that same problem with my rb20 and never yet found the problem either.. and i dont even have boost solinoid and the canister hooked up.

[leesredgt]

so your havin the same problem to?its weird i thought i had everything hooked up right?

[SIL-LINE]

Check your fuel filter and plugs , I had that prob before changed both and its gone. Sometimes its something as simple as that and it gets overlooked ....

Good luck on that guys

[leesredgt]

im know its not the fuel filter b/c i put a Z32 TT one on and i dont think its the plugs b/c it idles awsome it idles better that my 3000gt and ive tornthat engine down and almost redone everything except the block. would the CAS have anything to do with this possibly?the only reason i think its a vac hose is usally when u have crappy plugs the car will still drive and go through all the gears with mine it will NOT go past 20-30 mph it dosent matter how hard i hit the gas peadal it just makes it go to 20-30 faster and then it starts again i mean its pretty bad me and my dad thought we were gonna have to push it home there for a sec thank god i live only 2 seconds away from a gas station i can turn around in.

[eh?]

check your maf circuit.

[leesredgt]

this is gonna sound stupid but how do i do that?

[leesredgt]

so does it look like all my vac lines r hooked up right?

[USMCgetsome]

your issue seems like a faulty maf or faulty maf wiring. I'm not sure about rb20's ask a few of the homies on here. As for the lines for the boost solenoid. It's simple. U need a vaccum source line such as the one that is coming off the intake manifold. those 2 line are for the blow off valve and the other is for the wastegate. Find one that travels to the waste gate and take it off and put it to the line in on the boost solenoid. Then take the output and install it to the wastegate. Viola! get to boostin!

[2ndlife]

May not be related to your problem exactly but I had the exact same symptoms on a RB26dett before. The air flow meters were failing and did the same thing, drive to 2-3k rpm and dies. But able to start back up immediately. Had to drive it really slow to get home one evening. These meters are known to be problematic. Took them out and cleaned them and was able to squeeze another week of use out of them. Then I ended up changing both of them since I wasn't sure which of the two/or both was the culprit.

[eh?]

Download the R33 FSM, it's a must for this swap.

ECU pin 27 is the maf (afm) connection to the ecu. Verify the voltage to it.

[Darius]

Stuttering at around 2500-3000 is typical of a MAF issue. Most likely wiring. I'm going to jump on the bandwagon late here and +5 that suggestion.

[silviasgp06]

im confused how someone can go and do a RB swap, or any other popular nissan swap without knowing or reading about the MAF fail safe subject. not to bash or flame but have fun, hopefully thats the problem

[leesredgt]

thats the thing i didnt do my wireing i had wiring speacilties do it so i wouldnt have to mess with the wires.

[catch221134]

I have a type II rb25det, and it just did the same thing while I was on the highway last week. It had been running great though for almost six months.

I thought a vacuum or boost leak, so I did a boost leak test on it, and really didnt notice much, except for some air leaking out the exhaust side. (Which I have talked to people on this and had two reactions, A) Either those exhaust gaskets are going bad or the turbo, or B) its normal and the boost just leaks out the exhaust side when the turbo is gradually spinning.)

I did, notice when I was doing a field diagnosis(on the side of the road) That if i unplugged my maf(stock Rb 25 maf) That it wouldn't die, or change at all.

And from my other cars, I knew they would either die, or run awful.

But, as of right now, I think MAF. Well I hope, because I really dont want to take my turbo off in the car(s13).

But my car revs up to exactly 2k, and then sounds like half of the engine is shutting off. (seriously) But starts great, and idles perfect too. But as soon as it gets to 2k and positive boost, it cuts' back. Even if i push my foot to the floor, and there is a little grey smoke out the exhaust.

hope that helps, or just doesn't add to the confusion. I would say build a boost leak detector, first and for most, and readily do one on you car, and then test your maf.

oh and to the person flaming above, I have done several swaps, and even done the wiring on a few, and never have had to test a maf. =) And yes i did this swap on the floor of my garage, and it runs like a beast.... usually

[Coolwhip]

Hey Bba.

I have a 5 pin SI MAF, no good for you

text me on my cell.

[leesredgt]

hey coolwhip how much do u want for the MAF? my engine is a series 1.it does work right ? also do you have th estock hot pipe thats coming from the turbo u can see in the pics i had to make my own. the maf i have on the car i bought off a member from nico i wont mention names but he said it was in working order u see how far that got me. oh and one more question can i just replace the filiment in the maf b/c i really dont have 300 buck to spend on a new maf i was hoping to get my exhuast done,
Modified by leesredgt at 10:50 AM 11/14/2007

[leesredgt]

ok i started my car and then unpluuged the maf and i shut off just like its supposed to so is the maf good or not nessicerly.

[Coolwhip]

email me - Coolwhip@tmail (dot) com

or AIM - Bboy Coolwhip1

I can ship it out today via FedEx

[leesredgt]

email sent

[leesredgt]

ok so now that i unplugged my maf and then engine dies is the maf still good or can it still be bad or is my turbo shot?

[leesredgt]

i dont know if this matters but it only shuts off when its under load. i can sit there and rev it and it will rev past it all day its only when i drive it is when it fells like it gonna crap itself.i dont think its the maf of course i could be wrong i unplugged it and the car shut off does thaat mean its good or just messing with me.thanks

[Darius]

Look up the MAF sensor test procedure in the FSM and check it out. So simple to do but you might need a buddy to help.

[leesredgt]

befroe i go and do all of these test shouldnt by me pulling it out then the engine dying tell me its working right there? im not trying to question you im just curious.i mean it runs good with it and as soon as its unpluged it dies.oh and one more of my stupid questions maybe im reading it wrong but the eccus in the manuel is that there calling the ecu.

[catch221134]

Yo kat, it could be a couple of things, Is there other things going on with the car? like when you turn on your head lights, does your radio flicker, or things like this?

What gauges are you running? Are they also acting shifty? like when you touch the brake pedal.

I know to all others these maybe weird queries, but I had several people look at my situation and all it was a simple ground wire issue.

So to leesredgt: When you did your swap did you hook up the Coil pack ground? on your stock ka it was a braided wire at the fire wall and then to a bolt around the back driverside of the engine.

I hooked one up on my car, since we all over looked it(professional mechanics also) And then ripped it down the street with a big smile on my face.

And amazingly enough the car ran fine for a long time with out it, and then one day this problem happened.

Hope this help's out man. But do what the guys say and do a simple voltage test on the above said things, and then you know, what its not.

Ohh and wad dup coolwhip

[leesredgt]

no none of my electronics do that and as for the ground its the silver steel braided one your talking about right.if it is then yeah i got it hooked up but i also i repainted my engine bay so maybe im not getting a good ground ill check that out tomorrow to.thanks

[leesredgt]

could the problem be a faulty coolent temp sensor?will a Z32 TT sensor work?if so ill go and get one and try it.

[leesredgt]

ok me and my dad checked the MAF its good and we checked the voltage source its good to and we fixed one major boost leak.so after we verified the maf was good and fixed the leak we went and drove it again the car still wont go above 3000rpm.on the wiring specalties website they have there trouble shooting section nad the two things that are said to cause this is a bad MAF which mine is good and a faulty engine coolant tempature sensor me and my dad have been wondering about that b/c the gauge hardley moves but somtimes it does but most of the time it dosent so could this be causeing my problem?

[doc_tai]

could the problem be a faulty coolent temp sensor?will a Z32 TT sensor work?if so ill go and get one and try it.

98 ka coolent temp sensor plug right in my rb25det II

[eh?]

Are you verifying Maf voltages at the ecu connector or the maf connector? The water temp sensor the dash uses is not the same the ecu uses. The dash sensor is a single terminal sensor, did you swap the rb25 sensor out and install the KA?The ECU sensor has two terminals, the sensor should read about 0.3k Ω at operating temp.