Greetings from Saint Louis! 1989 Nissan Sentra. Trouble began as being able to drive only a short distance when the engine was cold (sometimes a block, sometimes a few miles) before losing all ability to accelerate (very scary). The engine would stay running but stepping on the gas pedal gets me little or no acceleration. Next when the engine was cold it developed a rough idle. Now after a cold start, the engine usually just dies. It still does start every time. But before it has a chance to warm up, it frequently dies. If the engine does get warmed up, it will idle and run.
JUst a hunch here, but have you looked in the tailpipe to be sure it is not obstructed.
I have seen where someone…in the process of backing up…backed into a dirt pile and plugged/partially plugged the exhaust. Partially plugged would allow the engine to idle, but no real acceleration on the road.
You could also have a plugged Catalytic converter.
Hi and thanks for the idea. A couple months ago, due to rusted pipes, I replaced the flex pipe, cat, and intermediate pipe. Exhaust shop told me at the time that my muffler is rusting from the inside and gave it less than a year before needs replacement.
Have gone through 3 mechanics already-all unable to diagnose the problem. I’m posting here hoping for some input.
Since your muffler is on it’s way out, why not get it replaced? I like where @Yosemite was going with a partially obstructed exhaust. Have you ever had your fuel pump and filter replaced?
Easy solution, keep the tank at least half filled at all times. But this points to a bad or clogged fuel pump. Or possibly a lot of water in the tank, which collects in the bottom.
I thought of that, but I’m unfamiliar with fuel pump construction. I recall something about it floating in the tank, or is it just the intake that floats? Sorry for my ignorance…
Pyrolord, I have delayed for two reasons. The muffler has a lifetime parts and labor warranty from Car-X. In the past, they fought me tooth and nail on honoring the warranty. So I figured I need a nice rust hole just to start a conversation w/them. What I have now is a coughing muffler and a muffler dripping a lot of water (small pool under the connection between the intermediate pipe and muffler) but no rust holes or loud noise. The other big thing stopping me is I would need to tow the car to them. Reason is I tried to start the car just now and it died.
This is with a full tank? so the problem is NOT fixed by keeping the tank full?
Take a rubber mallet and bang on the bottom of the gas tank, and see if the engine starts.
Hi Bill let me update you guys. On Tuesday, March 13 my mechanic spent 5 hours trying to figure this out. At the very end of the day he wanted to test something under the hood but he needed to relieve pressure in the fuel line (at this point the gauge was around the empty mark). So we got a container to catch the fuel from the disconnected hose while I turned the key to the “on” position. What came out surprised him. Pale yellow color and he said smelled very weak. He didn’t like it so we drained about a half gallon. That still left a little remaining in the tank. Then we took a gas can (1.65 gallon) to the BP station, filled it up, added it to the tank. So I’m at maybe an 1/8 tank. I start the car and it stalls. Mechanic quits and goes home. Next day, I walk to BP again. Add another 1.65 gallons to the tank. Now I’m just above 1/4 tank. Start the car and it idles, accelerates, and runs. I drive around town and do some errands (maybe 5-6 miles total). One of the errands was to add an additional 3 gallons of gas for “insurance” (Shell station). So end of day yesterday I’m at half a tank. This morning I wake up w/the idea to take the car to the shop that did my new flex, cat, and intermediate pipe for a clogged exhaust system check. No luck. Back to start and die. I could keep walking to the BP station and filling the tank in the hope the car will run but if anyone needs to examine the tank it seems like a full tank would be hard for them to drain. One other thing if it helps: about a year ago the fuel gauge needle stopped rising to the top. That is, I pump gas till it clicks off but gauge won’t go to full mark.
Hi Tester, over a month ago my first mechanic, without testing it first, replaced my original fuel pump with a new one. We went for a test drive. Car had great pick up and acceleration. Paid him and off he went. Couple days later I drive about 4 miles and lose ability to accelerate. Car was towed back home.
How long did this vehicle sit before you started driving it?
The gas on the left is fresh. The gas on the right has gone bad.
It’s a grocery store car. Lots of local trips. The car sat in my driveway for 1-2 days before it failed again.
When I was pumping gas into my gas can it looked clear from the pump. So I’m surprised your sample of gas looks pale yellow. Here are my pics from Tuesday…
That loks normal in color.
I would try adding some “Heet” or other product that will absorb any water that is in the tank.
That gaslooks normal to me too. Let it sit overnight to see if it forms into layers. If it does it is contaminated. Especailly look for a thin clear layer at the bottom which would likely mean water contamination.
I doubt that’s the problem though. My guess is you have a fuel pressure problem. You may need to have a shop install a fuel pressure gauge and drive the car around while monitoring the fuel pressure. My guess is that when the problem occurs the fuel pressure is dropping dramatically. if so, suspect the fuel pump, fuel pump electrical supply, debris in the gas tank, or clogged fuel filter. Just b/c you’ve got a relatively new fuel pump doesn’t mean it is working.
I wish I had saved the gas but I did not. Yosemite mentioned water in the tank. Would water in the tank only affect the engine when cold? I’m thinking back to the day I added the gas…that was an incredibly warm day in St. Louis. And the engine only starts and dies when cold. When hot, the engine runs much better but when the fuel level drops below a quarter tank I lose power again. Even when I lost acceleration while driving it was frigid temps and only a few miles from home-so I bet the engine did not even have time to warm up yet. So the problem is a combination of having a cold engine and a low fuel level.
To your points, already installed a new fuel pump (it’s so loud I can hear it working under the back seat) and fuel filter. Would the regulator, debris in tank, or fuel pump electrical fall into a cold start and low fuel level problem?
Yosemite, would water in the tank only affect the engine when cold and when low on fuel?
If you have low fuel pressure, that would show up more when the engine is cold than when it is warmed up. Cold engines need considerably more fuel delivered from the injectors to run properly than warm engines for a given load. Poor spark and/or compression could act the same way. Somehow your shop has to figure out as the first step whether this problem is caused by fuel, spark, or compression. Until that’s determined, gonna be very hard to solve. If a thorough visual inspection of the pertinent parts doesn’t show anything wrong, a fuel pressure test or a fuel trim measurement is a good way to get started. You need some hard test data to work with, rather than guesses.