Mechanics

INTERMITTENT STARTING

1989 Plymouth Acclaim • 4 cylinder FWD Automatic • 55,000 miles

1989 Plymouth Acclaim starting problem- It starts intermittently. Sometimes the fuel pump turns on for the 2 secs in ACC, sometimes not. When it does not, I put gas straight into engine/cab/fuel injector, or whatever you want to call it. It will then start and run fine. All ready replaced the 'Hall Sensor'/magnetic pickup, no change. What now? Also have already tried shaking the wires in the engine compartment as another said they did w/success. No change. Is it the ASD relay (if so, where is this) or is it this splice I have heard about, and if so, where is it?
Please help, I am afraid of shutting down on the highway.
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89 Acclaim
February 25, 2011.




The clue is it starts when you give it a priming squirt of gas. The Engine Computer is supposed to do that based on temperature. You might try a coolant temperature sensor. If you have access to a scanner that can display live sensor data it will show whether the sensor is reporting the correct temperature. Some cars also have an ambient air temperature sensor in the front left corner of the throttle body assembly.

It's probably more common to have fuel pressure bleeding down when the car sits overnight. There are two clues. First, it will start easily shortly after stopping the engine. More importantly, since you know about that short burst from the fuel pump when you turn on the ignition switch, that might not be enough time to get fuel pressure back up high enough for starting. Turn the ignition switch on to get the two-second burst, then turn the switch back off. Wait a few seconds then do that a second time and maybe even a third time, then crank the engine. If it always starts that way suspect a leaky injector but it could also be the check valve in the fuel pump or a leaking pressure regulator.
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Caradiodoc
Feb 25, 2011.
I don't have access to a scanner, I am new to all these electronics in cars. I own a '66 Corvair that does not have any of these problems, nice/simple mechanical fuel pump.
The Acclaim's fuel pump works sporadically when trying to start the car. No rhyme or reason. I don't understand why it could be an injector, when, from what I understand, the injector isn't getting the gas it needs to start the engine because the fuel pump didn't turn on and squirt gas into the injector. When I dump gas into the engine, it starts, sometimes it takes two or three of these "pouring gas in" procedures to get it to stay running. This is why I think the problem is an electrical or electronic one.
I am going to try removing the ASD relay and jumping the connections as is described in another post here to see if I can get the pump to run on the times when I try to start it and I don't hear that hum of the pump squirting gas for those 2 seconds.


Tiny
89 Acclaim
Feb 26, 2011.
Sorry, meant the post about the Fuel Pump Relay and checking the #30 post for voltage and then putting a jumper on it. I just was going to do this, except the fuel pump is turning on every time I try it today. I even tried it a bunch of times in a row, but it is working today! Damn Gremlins!


Tiny
89 Acclaim
Feb 26, 2011.
Unlike GM pumps that often fail while driving, Chrysler pumps almost always keep going once they've started up. When they fail they do not start up. If you hear it run for that first two seconds, the engine should start and run. I suspect when it isn't starting up on its own, it does start from the engine vibration when you squirt gas in. An intermittently non-starting pump would be much more common than a lack of a priming pulse from the injector due to a false reading from a temperature sensor.

When you do catch it not starting and you want to jump the fuel pump relay, use the diagram below and jump terminals 30 and 87. If you see a small spark when you make the connection you'll know the wiring is intact. If there is no spark, suspect worn brushes in the pump motor.

The injector problem I was referring to was not a defective injector. Here again, GM has a huge problem with their injectors. Chrysler hardly ever has a bad one. What can happen to them is the pintle valve leaks. That is not a problem while the engine is running, but when you stop the engine that fuel pressure in the supply line should stay there for weeks without bleeding down. A leaky injector will bleed the pressure down in a few minutes to a few hours. THAT's what can make it hard to start the engine. Since battery voltage is drawn down by the starter, the pump runs slower than normal during engine cranking. As fast as it builds up a little pressure the firing injector bleeds it off right away. Fuel is going into the engine but not enough for it to burn successfully so the engine doesn't start. That's where cycling the ignition switch two or three times before cranking the engine can help.

I couldn't agree more with you about all of the unnecessary, complicated, unreliable computers on newer cars. My daily driver is an old rusty trusty '88 Grand Caravan. You and I only have a very reliable Engine Computer. I've been complaining about the insane computers on newer cars for years.

Caradiodoc


Caradiodoc
Feb 26, 2011.
Thank you so much for your help. The Acclaim finally started acting up again and wouldn't start. I got out my trusty hammer and gave the gas tank a couple taps. Low and behold, it started, so I guess it was getting ready to fail. I just got it back from the shop, had a new fuel pump installed. So far so good. Thanks again!
Kurt


Tiny
89 Acclaim
Mar 5, 2011.
I'll be keeping my fingers and toes crossed that the problem is solved. I'm overdue for some good news!


Caradiodoc
Mar 5, 2011.

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