[240sx_s14]

Hey everyone I need some help.. My car runs terrible when it is cold what so ever. When I first start my car up in the morning I can't even rev the engine, it just cuts out and has really bad throttle lag. Once the car is fully warmed up I can somewhat drive it but it cuts out really bad when I get over about 2500 rpms and black smoke comes out of the exhaust so it is running rich. Now if it is a hot day out, and my motor is warmed up.. it runs like a dream and doesn't cut out what so ever. My temperature sensor on my gauge cluster is maxed out at hot when the motor gets warmed up, I don't know why.. I put a ka temp sensor in place of my sr sensor to see if that would fix it and it still reads HOT! One thing I took note of, when I went to changed temp sensors, no fluid came out when I removed my sr sensor, it was dry inside. And no my motor is cooling fine, I have dual flex fans with an electronically activated by temperature, and my coolant level is fine.

**65 degrees or higher outside, my car runs PERFECT once warmed up. Anything below that, it will cutout no matter what***

So I have a feeling that my car running rich like this and cutting out has to do something with either my gauge temp sensor, or my ecu sensor. But I don't know how to test this or what to look for. Help please ? I'd really appreciate it guys.

 

[trmn8r]

Hey everyone I need some help.. My car runs terrible when it is cold what so ever. When I first start my car up in the morning I can't even rev the engine, it just cuts out and has really bad throttle lag. Once the car is fully warmed up I can somewhat drive it but it cuts out really bad when I get over about 2500 rpms and black smoke comes out of the exhaust so it is running rich. Now if it is a hot day out, and my motor is warmed up.. it runs like a dream and doesn't cut out what so ever. My temperature sensor on my gauge cluster is maxed out at hot when the motor gets warmed up, I don't know why.. I put a ka temp sensor in place of my sr sensor to see if that would fix it and it still reads HOT! One thing I took note of, when I went to changed temp sensors, no fluid came out when I removed my sr sensor, it was dry inside. And no my motor is cooling fine, I have dual flex fans with an electronically activated by temperature, and my coolant level is fine.

**65 degrees or higher outside, my car runs PERFECT once warmed up. Anything below that, it will cutout no matter what***

So I have a feeling that my car running rich like this and cutting out has to do something with either my gauge temp sensor, or my ecu sensor. But I don't know how to test this or what to look for. Help please ? I'd really appreciate it guys.

im gonna have to guess the the temp of the vehicle is having to do with your problem . you have to bleed the cooling system. and make sure there are no air pockets. check with an infrared thermometer and see if the thermostat opens when it has to. id first fix that problem before going forward.

 

[240sx_s14]

Ok I bleed my cooling system and there is fluid behind the temp sensor. It is still reading all the way hot. I used a temp gun on my radiator lines and at the hottest it was 186 degrees, and I also took a reading at the temp sensor and it was around 176 degrees. But my gauge cluster is reading all the way hot still. I replaced the sensor and it did not fix it. My engine block read 192 degrees after I had been running it hard on a warm day. Nothing over 200 degrees even aftering I've been out boosting!? I have not messed with my ecu temp sensor, I have only messed with the gauge cluster sensor, because I would like an acurate temp reading inside my car. Like you said, I would like to get this fixed before I figure out why my car cuts out. Any suggestions on what to do next ?

 

[rogoman]

Once the car is fully warmed up I can somewhat drive it but it cuts out really bad when I get over about 2500 rpms and black smoke comes out of the exhaust so it is running rich. Now if it is a hot day out, and my motor is warmed up.. it runs like a dream and doesn't cut out what so ever.

This sounds like a MAF problem. Check the voltages.

 

[trmn8r]

Ok I bleed my cooling system and there is fluid behind the temp sensor. It is still reading all the way hot. I used a temp gun on my radiator lines and at the hottest it was 186 degrees, and I also took a reading at the temp sensor and it was around 176 degrees. But my gauge cluster is reading all the way hot still. I replaced the sensor and it did not fix it. My engine block read 192 degrees after I had been running it hard on a warm day. Nothing over 200 degrees even aftering I've been out boosting!? I have not messed with my ecu temp sensor, I have only messed with the gauge cluster sensor, because I would like an acurate temp reading inside my car. Like you said, I would like to get this fixed before I figure out why my car cuts out. Any suggestions on what to do next ?

so, so far you know that the car is not oveheating. the car is not saying that. id check the resistances from the engine temp sensor to your ecu and see if theresanything affecting it in that way. do what rogo says and see what you voltages read for the maf sensor. id do that.

 

[240sx_s14]

Does anyone know by any chance what the voltages should be for my maf. I'm running an E5 ecu, and a SOHC ka24 maf. I also checked my ecu for codes and got nothing. The car sputters like hell when I first start it up in the morning and is hardly drivable till it warms up and even then it sputters when I get into the throttle what so ever. I'm thinking I have the wrong MAF for the ecu I have.

 

[rogoman]

Why didn't you use the S14 OEM MAF with the SR motor?

 

[240sx_s14]

I'm using a stock sr maf now, I bought one from a friend and my car is still wanting to cut out bad. At idle in neutral I can rev it all the way to 7500 without any cut out. My ecu isn't putting out any codes, and my car likes to die on me when I'm pulling up to intersections but it fires right back up no problem. My boost gauge shows a consistent 25 vacuum reading at idle so I don't think I have any vacuum leaks, and I haven't pressure tested my turbo piping but I have checked over all of my couplings and tubing/intercooler very good and everything seems to be ok. I'm stumped...

 

[rogoman]

Do the hot pipe pressure test. The BOV may be opening up prematurely.

 

[240sx_s14]

Ok I'll give that a try and see what I come up with. Yesterday I decided to play around with my timing to see if that is what is causing my car to act up and I advanced it a good amount and took it for a drive to make sure it wasn't pinging or knocking and it was ok. So I drove it around let it warm up (still cutting out but not as bad, misfiring really bad at idle) but once I got into the throttle it would boost at 15 psi like a dream. But it still wanted to die on me at intersections and would cut out just a little bit at random times. I just don't understand because if it was a boost like, it wouldn't pull like it did yesterday and run 15 psi.. I also tried my buddy's ecu and maf together on my car since they work perfect on his blacktop but it still wants to cut out. So I have eliminated an ecu/maf problem. Does this sound like a bad sensor, or some time of weird boost leak? I don't even know where to look now..

 

[240sx_s14]

I tested the voltage to my MAF and with the key in the on position it put out .017 Volts from the signal wire, and with the car running it put out 8 volts. Is this normal? The car is running rich, black smoke comes out when I get into boost and it cuts out and there is popping out the exhaust. Just have no idea why.

 

[rogoman]

No, it's not normal. With the motor warmed up and idling, the voltage should be no more then 1.5 V.

 

[240sx_s14]

Ok.. Update on the car.. I found out that my tps sensor was hooked up but had the wrong wires going to it, so I ran the right ones that were connected to a different plug to it and then adjusted the voltage to 4.46V at idle. The car seems to have better throttle response but did not fix it from cutting out. I also found a boost leak coming from the coupler that is closest to the turbo, and fixed it but still did not fix my car from cutting out at higher rpms. It also runs terrible cold, can't even give it gas when I first start the car or it acts like a rev limiter at 1200 rpms and almost kills it, it has to idle at least 3 or 4 mins before I can give it gas.

Is there a good way to approach trying to fix the voltage to my MAF?

 

[rogoman]

You'll have to use an FSM and do a pinout check of the wiring.

 

[240sx_s14]

Ok I have normal voltage running to my maf now, all of my electrical seems to be working properly. The car still misfires bad at idle and cuts out when getting into boost, black smoke out exhaust.. HELP!!! please!! this is getting rediculous, I've been working non stop on this car for a month now and still haven't found the problem.