Engine slowly dies.......

[red240zenki]

Alright, well, I finally got my car all wired up right just last week. I start the engine and it fires right up. It idles for about one or 2 seconds then just slowly dies. I checked fuel pressure and its 38psi without vacuum. I have the Walbro 255, so I was expecting it to be much more than what it was, but it's only 38psi. I have messed with timging and the idle adjusting screw and it doesnt much. It still will slowly die. I know that there are no leaks in the IC piping either. I've checked that about 5 times now. It's very frustrating because it fires right up and acts like it wants to run, but it just slowly dies. Any suggestions?

[JonPowell]

Fuel pressure should be 43 WITHOUT vaccum and ~35 with. Start there.

[red240zenki]

That's what I thought. I'm waiting on my Nismo AFPR. Hopefully thatll solve this problem. Thanks Jon.

[240sxed]

even tho the fpr is off. a lot of times its the maf or something else? check your maf?

[JonPowell]

what exactly, in all your mechanical expertise, lead you to believe it was the maf? What about his symptoms told you that he is having problems? I have never seen a bad maf act like this, however I HAVE seen a car running out of gas act like this. Don't send this guy on a wild goose chase! That isnt nice, just to up your post count.

[USMCgetsome]

i've had similar problems. It eneded up being the 02 sensor not having a 12vdc signal source. it would crank, start, run for a min or 2 then die.

[HolyShiznit]

He has a fuel pressure problem, which means he has a clogged filter/sock/line or he has an empty tank. That's where he needs to start looking.

[eh?]

I ran my original RB swap with a walbro and stock FPR with no problems. Start up wise there is no difference then and now with the Nismo fpr.Have you tried holding the gas down while starting?Is the start wire hooked up?Are the fuel lines in the correct positions?Did you get any codes?

[red240zenki]

Holding the gas down with the engine on just caused it to hesitate. I will check to see if the start wire is connected. Which, from what I remember, it is. Fuel lines are in the right position. I tried putting them in the other way the engine wouldnt start at all. And I havent checked for codes yet. I need an OBD2 tester. On the R34 ECU, there isnt a screw you can twist to see if you are running codes. Hopefully, I will find the problem today.

[eh?]

Download the r34 fsm, it tells you how to put the ecu in diagnostic mode.When you held the gas down the engine was idling?

[red240zenki]

The engine CANT idle. It runs for about 5 seconds then dies. I have the R34 FSM, I'll look to see how to read up on how to get to the diagnostics.

[red240zenki]

Fuel pressure is now at 47psi without vacuum. Still wont idle though. I found out how to get the ECU's codes but I dont know where to put the two pins to get the MIL to flash because the S14 has a different consult reader plug than the R34. eh? do you know how to know which ones on the S14 consult plug are "IGN" and "CHK"?

[eh?]

You can do it at the ecu. I think it's pin 22 and 24.

[red240zenki]

Checked the codes today. It threw number 44, which is a "Malfunction detected in multiplex communication line between engine and TCS/ABS." Then on the TCS is throws a code of 13, which is means the DKR line isnt hooked up. I know that I didnt hook this up when I did all of my wiring, mainly because I had to no clue where to start with that. Could this be the problem? I checked the fuel pressure and when its running it remains steady at about around 43psi when the vacuum line is hooked to the IM. One thing I also dont have is the rubber peice coming off of the nozzle on the IM that connects to the I'm guessing where the PCV valve is. Would this be affected the engine at all? Originally when I got the engine the "PCV valve" was blocked off and the nozzle coming off of the IM was capped.

[Andrew85cm]

If what you are saying is that you have a vacuum line on your IM that is not connected to anything and not blocked off then you will want to block it off. You need all vac lines connected or blocked or whatever to maintain vacuum. That could be your issue but what are you saying about your PCV. You don't have one your's isnt working what??? You need that you are killing the environment lol.~ANDREW~

[eh?]

I honestly don't know if that would affect the engine starting.First try to hook up the tcs module.http://www.rb25det.org/rb/tcs.jpgsecond break out the multimeter and check all your main sensors.

[Bluefire]

Check for vac leaks, also make sure there are no leaks in the intake pipe and that all the intake air goes throught the maf first

-Bluefire

[red240zenki]

I have all that wired up except the DKV and DKR wire between the ABS and the TCS. I just didnt hook that up because I dont know what those are on the S14 ABS. My engine DOES have a PCV, just the hose from the IM isnt hooked up to because I dont have one. The IM is just capped off. Can I use a breather for that PCV side instead? I know on KA's and other engines you can. Or should I just get the stock hose that runs between the IM and PCV inlet.

[red240zenki]

I was bored today because I was waiting for the battery to charge. So, I took out all the spark plugs and they are all very dark black. I dont know why but I guess I was just overlooking something so obvious. So, I'm guessing that this is the main reason why my car isnt idling. The plug numbers on them are NGK's PFR6G-11, but the thing is that they are platinum. I dont feel like paying $11 a pop for plugs. Are the R33 spark plugs the same as the R34 spark plugs? Or are they different?

[Bluefire]

Just run some coppers... BCPR7ES-11 I believe

-Bluefire

[red240zenki]

Well, checked voltage on all the things that would cause the engine to stall like it does. TPS was fine, IACV was fine, MAFS was bad. We unplugged the MAFS and it seemed to run a little better without it being connected. Read in the manual that if you have 4.9+ V's in your MAFS, its bad. Mine was was around 5.3 or so. So the MAFS was causing the ECU to think that throttle was being applied. Which would explain why it would be barely run, and when I apply actual throttle it would die even more. Right now, I'm waiting for the new MAFS to get here and should be here today. Hopefully, this solves my problem.

[Mr.Sandman]

altenator maybe...

[eh?]

Double check your wiring, swapped + and - can cause that reading (as will a bad maf)

[red240zenki]

Actually, I didnt extend the MAFS wires, so it was still how it would have been stock. If thats where your saying the + and - could have been switched around. LOL. Im pretty sure I can remember accidently dropping my MAFS on the ground. Luckily, Venus is cool as is sending a new one out pronto.

[red240zenki]

Okay, got 2 new mafs yesterday from Venus. I tried both, neither worked. So it still slowly died. Now, I know I have fuel, spark and air. What else could it be? Is there anything in particular on an RB that will cause and engine to start up, but then just die. I do have a turbo timer that is partly installed, could this have anything to do with it? I dunno. Right now I'm just trying to start all over and see where I might have messed up. Any ideas???

[red240zenki]

Alright I found out what the actual problem was. I didnt realize that the MAF and boost pressure sensor were the EXACT same plugs. I switched them around and car fired right up. I let it idle for about 20 minutes and everything runs perfectly. There are 3 codes though. They are 26,44,and 46. One is TCS to ABS communication which doesnt show up on the MIL. The other is the boost gauge which I just connected and it that was fine. Then the next one is Throttle motor or motion sensor?I cant exactly remember what it is. But i'm pretty sure that the throttle sensor is what it is because when I apply throttle it hesistates.

[themadscientist]

what exactly, in all your mechanical expertise, lead you to believe it was the maf? What about his symptoms told you that he is having problems? I have never seen a bad maf act like this, however I HAVE seen a car running out of gas act like this. Don't send this guy on a wild goose chase! That isnt nice, just to up your post count.

I see this. then I see this.

Alright I found out what the actual problem was. I didnt realize that the MAF and boost pressure sensor were the EXACT same plugs. I switched them around and car fired right up. I let it idle for about 20 minutes and everything runs perfectly. There are 3 codes though. They are 26,44,and 46. One is TCS to ABS communication which doesnt show up on the MIL. The other is the boost gauge which I just connected and it that was fine. Then the next one is Throttle motor or motion sensor?I cant exactly remember what it is. But i'm pretty sure that the throttle sensor is what it is because when I apply throttle it hesistates.

somebody owes someone an apology me thinks.

[red240zenki]

K. Finally got it to drive. But VVT isnt working. Checked it and it's not getting a good ground from the ECU. Also, I keep blowing fuel pump fuses and thats with 20A fuse, not 15A .I have a Walbro 255. Anyone else have this problem?