nissan help...
11-06-2007, 03:02 PM
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nissan help...
i have a 94 nissan Altima that shuts off when it warms up. the car seems to start rough idling then shuts down .. it will restart and run again. does anyone know what the fuel pressure is suppose to be at? does the nissan distributors have problems? please any help.. thanks
11-06-2007, 06:15 PM
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Re: nissan help...
on a 240. which is the same motor. idk if same specs tho
at idling:
with FPR valve vacuum hose connected 34psi
with vacuum disconnected 43 psi
at idling:
with FPR valve vacuum hose connected 34psi
with vacuum disconnected 43 psi
11-06-2007, 08:16 PM
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Re: nissan help...
I don't think it's fuel, I think it's probably a sensor or idle air control problem. Fuel pressure won't change enough with temperature to make a difference, and the regulator will take care of any fluctuations anyway. If you have a bad sensor, the ECU will start making control decisions based on bad data, causing problems. The fact that it does it while warm is the key, because the ECU has different control modes before, during, and after warmup. THis means that mechanical controls, (like a fast idle thermo valve) can interfere with the ECU if the ECU is getting incorrect data from a sensor. This might not be an easy thing to track down though.. This could also be an idle air control valve problem; or the fast idle thermo valve could be bad. If the IACV is getting clogged, it might only be able to idle correctly if/when the FITV is open, which is when the engine is cold. THere are other things that it could be also, the best place to start is with the troubleshooting flowcharts in a factory service manual. And no, not a Haynes or Chilton manual, they're usually useless for actually doing something other than routine maintenance.
Last edited by Fabrik8; 11-06-2007 at 08:18 PM.
11-07-2007, 06:42 AM
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Re: nissan help...
Doesn't have to. CELs are only triggered when it detects a sensor is out of normal range, etc. There are degrees of sensor failure, not just totally broken or totally good. Anyway, I'm not saying thats what it is, but it's a possibility. Does your coolant temp gauge read correctly?
11-07-2007, 07:24 AM
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Re: nissan help...
My friends car did the same thing it turned out to be the distributor we wiggled the plug it would start then cut it off go to start it again and nothing.
11-07-2007, 03:16 PM
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Re: nissan help...
What does the temp gauge reading cold have to do with how the fans are wired? Are they running all the time? That may be a problem, if the coolant temp sensor reading is always too low do the ECU is not detecting the engine getting up to operating temp. Why aren't you running the fans with a relay and a temp switch?
I would tend to doubt that is the problem, but it could be. How do you know you're having problems when the engine is warmed up if the temp gauge is reading cold, or you're running the fans all the time?
I would tend to doubt that is the problem, but it could be. How do you know you're having problems when the engine is warmed up if the temp gauge is reading cold, or you're running the fans all the time?
Last edited by Fabrik8; 11-07-2007 at 03:18 PM.