Q: Hi, I have a 1990 Nissan Pulsar NX, when I start the engine the RPM goes up to 2000 and then comes down after 5 minutes of driving when the engine heats up. After that the idling will go down to 850-900RPM. Please advice. Thanks
A: I have the same make/model/year as your car. It does the same thing when idling, the rpm's go down. i dont belive its a problem. It could be just the way the car warms up.
I disagree . Engine speed should not be that high at cold start . The idle control is defective , it needs to be checked and the defective part replaced . This device pushes on the throttle plate making it allow air into the engine . If it is open to much , this will cause the high cold idle .
One of the things that such a high idle will do is cause an increase in engine wear . True , this is going to happen any way due to a lack of oil during initial start-up , but why hasten such wear .
Q: My car is only running on 3 cylinders.
I replaced the plugs, then checked all of the coil
packs, and made sure that the cylinder had
compression... everything checked out ok..
but one of the plugs isn't firing.
Is it the ignition modual that is bad and/or
what else could be the problem?
A: It's either a coil or an injector....change coils
around and if the ignition miss follows the
order of the coils...change the coil...same
with the injectors...one change at a time......Ed
Q: About a month ago the car started to burn black out of the muffler when accelerated hard, it has stopped burning black now, but still idles rough, the loss of power/acceleration is very noticeable, especially on hills. Is this a valve problem? This is the second time it has done this. The last time I got a tune up done, it ran great but now it's back to the same kind of symptoms. please help. thank-you.
A: You may have picked up a bad tank of gas. Run it hard for a few days, and then fill it with "high test" gas (high octane). Ed
Q: My car started running rough and my husband gave it a tune up. It has never started since. Now, nearly 3 years later, we are working on it. We have changed the fuel pump, PCV valve, and filters. It started, idled for ten minutes and won't start again.
A: Check your spark plug wires and make sure they are on in the right order.
Heating / Cooling System Malfunction Happens always Not applicable
Q: I had my pulsar converted to 134A refrigerant, and the AC still won't stay on. The compressor runs for about 15 seconds and cuts off.
If I keep pushing the on/off switch every few seconds, the air cools down eventually. I tried jumpering out the low pressure cutoff switch, which didn't change anything. The system pressure is right according to the aftermarket gauge I bought. The guy who did the conversion suspects a relay, and says the compressor works fine.
I don't know what relays to check, and can't afford to spend 60+/hr to find out.
A: Your problem could be a high pressure cut out switch. R134a systems run at a higher pressure than R12 and require a charge of only 80% of the new refridgerant when converted. You should ask the person that did the conversion how much R134a was used and compare the amount to the original specification for the car.
Drive Train / Driveline Won't Start Not applicable Always
Q: The car blew the heater core and got coolant all over the engine. It acts like its not getting gas. I also heard about a water temperature sensor.
A: You have either replaced the heater core with proper hose connections , or at least bypassed it , haven't you ? Water temperature sensor could be keeping the computer from allowing the engine to operate . Also , air in the coolant will tend to rise to the highest point in the engine . This can isolate the temperature sensor thus causing an inaccurate reading .