Eng surg - 1992 Plymouth Laser

Hi,

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NOTE: In order to perform a meaningful diagnosis, it is necessary to utilize either a code scanner or code reader. A test light, ohmmeter, digital voltmeter, vacuum gauge and jumper wires may be required. You do not need any of the aforementioned items to inspect vacuum hoses, wiring, or disconnected plugs or adapters.

There is no such thing as one fix fixes all. Be forewarned that some repairs require ripping things apart and extensive testing, repairing or replacing items, The multitude of possibilities require a modicum of skill, patience and more. It's always best to take your vehicle to your local service center.

But don't despair I'll attempt to provide you with steps to fix the issue. Hopefully, this will be satisfactory to you, If not, just let me know and I'll again try to remedy your problem.

Before undertaking any repair or diagnostic work, be sure to inspect wiring for proper connection, burned or worn/chafed spots, and cuts.

Be sure to check hoses that are hard to see beneath the air cleaner, compressor, alternator, etc.


The steps I'm going to outline are the same as we use in my shop for hesitation, sag and stumble. Out of the box, I'd say that you have a problem with the fuel management system. However, there's a good chance that it's something simple and inexpensive like a clogged fuel filter or water in the fuel tank. I

n fact, I suggest that you immediately replace the fuel filter and pour a can of Heet or any other product designed to remove water from the gasoline stored in your fuel tank, If that solves the problem then you need read no further.


All of the tools required can be borrowed from AutoZone at NO COST!

Sensors:

• The sensors can be checked with an OBD-II code scanner borrowed from AutoZone. Pay special attention to an TP (Throttle Position) warnings. The sensor can be manually checked for binding or sticking.
• Check the Heated Oxygen Sensor (HO2S) found near the firewall and screwed into the exhaust manifold for signs of corrosion on the threads. That will cause a faulty ground.

Fuel System:

• Check the fuel pressure with that fuel pressure gauge from AutoZone. You reading should be 40-45 PSI and holding steady.
• Contaminated fuel is a constant problem and if the pressure does not hold steady, replace the fuel filter.

Additional Checks:

• Make certain that the engine thermostat is functioning and is the correct temperature.
• Make certain that the alternator voltage output is not less than 9 volts nor more than 17 volts.

Here's a little general information that will assist you in comprehending the readouts from the code scanner. This is simply for your edification. You may be aware of all this but we've never done business before and all assumptions are off the table.

For an engine - make that any engine and irrespective of manufacturer - to run, you need three things to happen inside the engine, compression, fuel and ignition, without any one of these components the engine will not run.

• Compression - Engine compression caused by crankshaft rotation and pistons moving up and down inside the engine block. If the timing belt or timing chain fails it will cause the camshaft to become out of correlation with the crankshaft or allow the camshaft to stop rotating. Either of these conditions will cause the engine to lose compression and sometimes cause internal engine damage.
• Fuel Delivery System - The fuel system includes: fuel pump, fuel injectors, pressure regulator, fuel filter and pressure lines. This system is used to supply fuel under pressure to the fuel injection system, the lack of fuel pressure or volume will cause the fuel delivery system to fail and the engine to stall or not start.
• Ignition Spark Delivery System - The ignition system components include: spark plugs, spark plug wires, distributor (if applicable), crankshaft angle sensor, camshaft angle sensor, ignition coil, ignition module, knock sensor and PCM (powertrain control module). The engine relies on the ignition spark to be delivered to the combustion camber at the correct time. If the ignition spark stops or is delivered at the wrong time the engine will not run or run poorly.

If Your Engine Cranks but Does Not Start Follow this Troubleshooting Guide (This doesn't necessarily pertain to you but it's useful to know)

Most vehicles operate by the same principle; basic troubleshooting procedures apply to most cars.

• Step 1: Anytime you have a problem with electronically controlled components such as an engine, transmission, ABS brake, or SRS (supplemental restraint system, Air Bag) inspect all fuses using a test light and check the under hood power distribution center and under dash fuse panels. If all fuses test okay continue to the next step.
• Step 2: To check for problems with electronically controlled components such as an engine, transmission, ABS brake, or SRS (supplemental restraint system, Air Bag) and the fuses test okay a trouble code scan is needed to identify any system trouble. Use a simple scanner tool to retrieve trouble codes and see if they relate to the specific problem, like a crank angle sensor failure code. If the trouble code present does not pertain to the immediate problem like an EVAP code ignore it until a later time, after the car is running.

Scan the system again after the vehicle is running. The reason is that non-related codes can be detected after the engine is running because sometimes false codes can be triggered by the engine not running. Once the engine is running again the code present might cycle and turn itself off. You might say "if the engine doesn't run shouldn't it have a trouble code?" Sometimes conditions occur that will not be detected by the computer, example: if the fuel pump fails the computer cannot detect the failure, so the engine doesn't start and the computer thinks everything is okay with no codes. If no trouble codes are present proceed to the next step.


The Wells Company offers extensive code diagnosis application information and technical support via its Tech Line at 1-800-558-9770, as well as in-depth product and repair videos at www.repairpath.com (use my personal access code carrepair) and through the "Wellstech" channel at www.YouTube.com

All the best,

Ben