zzzasy Posted February 10, 2006 Share Posted February 10, 2006 My car ('98 OBW) hasn't been running in about 5 months. I have changed the crankshaft position sensor, knock sensor, and camshaft position sensor. The symptoms are when the car is cold it runs ok. Once it reaches operating temps, it starts cutting out like lack of fuel and do not want do go over 40mph. Although I changed the camshaft position sensor, I'm still getting the camshaft code. This is what I was told by the dealer's mechanic. He wants to start by addressing the camshaft position code. Thus, he wants to check the timing belt to see if its off for $490. Of course, I declined. Also, he said this would only be adressing the CEL. What do you think? If the car is running good when cold (closed loop), wouldn't that mean the timing is ok. I thought if the timing was off it would run the same whether in open or close loop. I asked him this question and really didn't get an answer. zzzasy Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 10, 2006 Share Posted February 10, 2006 i think youre on the right track, i can't imagine the car running fine when cold if the timing belt was hosed. although having a cam position sensor i can see why he's so intent on checking it out on an interference motor. ECU is cracked up on the wiring to one of the sensors could be shorted/bad? probably a good idea to test continuity resistance of the cam sensor wires from the ECU pinout if you have new sensors but still have the code. i don't know the spec's of those sensors, you'll need an FSM or someone to tell you. dealer can tell you if you can't find it elsewhere. ask for the resistance of teh sensor, or test it and compare to someone else's. Quote Link to comment Share on other sites More sharing options...
zzzasy Posted February 10, 2006 Author Share Posted February 10, 2006 I'm assuming he tested all that because he agreed with me that the sensor was not bad. He suggested looking at the belt because the sensor was fine. When I get a warm day, I will pull the front cover and check the timing belt and timing marks. I bought this car for the winter months and I have had it for three winters now and each winter its has not been running. Runs great during the summer. zzzasy Quote Link to comment Share on other sites More sharing options...
Meeky Moose Posted February 10, 2006 Share Posted February 10, 2006 i had an old cavalier than ran like ************ when it warmed up but good when cold.. it also kept spitting out the same code even tho the sensor was fine.. i changed the ecm and all the problems were fixed.. you might have a bad ecm.. Quote Link to comment Share on other sites More sharing options...
zzzasy Posted February 10, 2006 Author Share Posted February 10, 2006 I was thinking about replacing the engine, but if its the ECU that would be a waste of money. Is there a way to have the ECU tested? Quote Link to comment Share on other sites More sharing options...
Dickensheets Posted February 10, 2006 Share Posted February 10, 2006 Look for a "pick a part" junk yard and find an ECM. Just a thought. rd Quote Link to comment Share on other sites More sharing options...
dxrflyboy Posted February 11, 2006 Share Posted February 11, 2006 It sounds like the problem occurs when the ECU is running in "closed loop" (when the O2 sensor is warmed up and adjusting the A/F mixture). You will need to retrieve the DTC (diagnostic trouble code) and follow the diagnostic procedure in the manual to pinpoint the cause. This is the only way to correct the problem. If the dealer isn't following this procedure and is guessing with your money, you need to find somewhere else to take the car. Quote Link to comment Share on other sites More sharing options...
dxrflyboy Posted February 11, 2006 Share Posted February 11, 2006 Also, I'm not sure of this since I haven't done my research, but engine may also run in "batch fire" mode (all injectors fire at the same time) until it warms up, then runs in sequential mode (fires each injector individually based on camshaft position). This would explain why it may run OK cold but not warm. But I wouldn't pay $450 just to CHECK this! The end covers come off separately from the center cover, making a timing check a fairly simple procedure. I could understand the $450 bill to REPLACE the belt, but not just to check the timing! Quote Link to comment Share on other sites More sharing options...
Commuter Posted February 12, 2006 Share Posted February 12, 2006 What about coolant temperature sensor? I've read that they mess things up like this if they are shot. The ECU thinks the engine is still cold even though it has warmed up. However, you are not getting a code for it, so I could be off base here. Just a thought, since you are getting different behaviour between cold and warm engine. Commuter Quote Link to comment Share on other sites More sharing options...
cookie Posted February 12, 2006 Share Posted February 12, 2006 Often don't get a code with coolant sensor. The engine just thinks its hot. Quote Link to comment Share on other sites More sharing options...
zzzasy Posted February 13, 2006 Author Share Posted February 13, 2006 I'm not having any overheating problems. If that sensor was bad wouldn't the fan not come on the car start to overheat. I changed the coolant temp sensor last summer. I will double check it because I did screw up the connector when I tried to take it apart. zzzasy '98 OBW Quote Link to comment Share on other sites More sharing options...
edrach Posted February 14, 2006 Share Posted February 14, 2006 I'm not having any overheating problems. If that sensor was bad wouldn't the fan not come on the car start to overheat. I changed the coolant temp sensor last summer. I will double check it because I did screw up the connector when I tried to take it apart. zzzasy '98 OBW Unless your later car is different than my '91 EJ22, there are two temp sensors on the motor. One feeds temp information to the ECU and I suspect turns on the fan when necessary; the 2nd one feeds your temperature guage to display coolent temp. Quote Link to comment Share on other sites More sharing options...
RallyKeith Posted February 27, 2006 Share Posted February 27, 2006 Unless your later car is different than my '91 EJ22, there are two temp sensors on the motor. One feeds temp information to the ECU and I suspect turns on the fan when necessary; the 2nd one feeds your temperature guage to display coolent temp. Ed is right about there being two sensors but didn't point out what the one thing the ECU really is doing. It's main job is to tell the ECU if the engine is cold or not. If the engine is COLD it RUNS RICH, once it gets up to temperature it runs normally. If that sensor is bad it will often times think the car is cold when it is really warm and the car will run rich. The most common way to find this out is when you go to start the car when it is already warm, it will flood the engine and it won't start. Quote Link to comment Share on other sites More sharing options...
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