I have a 98 Chevy Malibu Base V6 that has been giving me headaches. I can't find a mechanic to figure out what is wrong with this car and I am at a loss, and really need to get this car fixed. Here is the best description I can give....The car sat for 2 years. We sold our new car and decided to fix this one up but are now regretting that decision. The car runs great until it heats up to about the half way mark, and I can pinpoint it to the exact line that the problem will start. The car will begin to "Lose power" or cut out. I have the gas pedal pushed all the way down and the car seems like it is not getting any gas at all for a few second and then it will take off for a few seconds and then cut out again. We changed the ignition control module and the problem seemed to stop for about 60 miles and then started again. We've had the car to about 5 mechanics and no one can tell us what it is. The latest one told us it HAD to be the fuel pump so we bit the bullet and paid the $400+ it cost to get it changed. Ran awesome for about 2 days and now it is doing the same thing again!!!! We suggested the crankshaft sensor and the mechanic told us that would not cause the problem and that he would have use a tech 2 machine to reset the whole computer! Even the chevy dealership said they are stumped. The car is not pulling any codes and the check engine light is not on. When the problem is happening the rpms jumps up and down between 0 and 3 and the battery light flashes red with intermittent dinging! Can someone please give me some ideas...or has this happened to anyone else? We have no other vehicle and I have 3 small children We've changed -Starter -Ignition Control Module -Fuel Filter -Fuel Pump -Flushed radiator and cleaned thermostat

SOURCE: HELP! HELP! SOMEONE PLEASE ! 2001 chevy blazer fuel problems

I would check to be on the safe side the fuel filter is going in the right direction. The arrow is pointing towards the engine away from the fuel tank, Then you need to make sure the fuel pump wiring connections are good contact and did not come loose when driving.

SOURCE: 2001 Chevy Malibu, 89,000 miles, 3.1 engine, won't start

CLICK HERE for the injector schematic.
CLICK HERE for the Ignition schematic.

Since the PCM uses info gatheres from the crank and cam sensors to calculate ignition - and there are no OBD codes - in all likelihood, the PCM itself is bad.

The Ignition Module, also transmits to the PCM.

It appears after all your testing - that the PCM is at fault.

It does not error report on itself (unfortunately).

The ignition timing is controlled by the Powertrain Control Module (PCM). No adjustment is necessary (distributorless ignition) or possible.

Please see the following....

The ignition timing is controlled by the Powertrain Control Module (PCM). No adjustment is necessary or possible.
The engines covered by this manual are equipped with distributorless ignitions, ignition timing is controlled by the Powertrain Control Module (PCM), as applicable. No adjustments are possible. If ignition timing is not within specification, there is a fault in the engine control system. Diagnose and repair the problem as necessary.
Ignition timing is the measurement, in degrees of crankshaft rotation, of the point at which the spark plugs fire in each of the cylinders. It is measured in degrees before or after Top Dead Center (TDC) of the compression stroke.
Ideally, the air/fuel mixture in the cylinder will be ignited by the spark plug just as the piston passes TDC of the compression stroke. If this happens, the piston will be at the beginning of the power stroke just as the compressed and ignited air/fuel mixture forces the piston down and turns the crankshaft. Because it takes a fraction of a second for the spark plug to ignite the mixture in the cylinder, the spark plug must fire a little before the piston reaches TDC. Otherwise, the mixture will not be completely ignited as the piston passes TDC and the full power of the explosion will not be used by the engine.
The timing measurement is given in degrees of crankshaft rotation before the piston reaches TDC (BTDC). If the setting for the ignition timing is 10 BTDC, each spark plug must fire 10 degrees before each piston reaches TDC. This only holds true, however, when the engine is at idle speed. The combustion process must be complete by 23° ATDC to maintain proper engine performance, fuel mileage, and low emissions.
As the engine speed increases, the pistons go faster. The spark plugs have to ignite the fuel even sooner if it is to be completely ignited when the piston reaches TDC. Spark timing changes are accomplished electronically by the engine and ignition control computers.
If the ignition is set too far advanced (BTDC), the ignition and expansion of the fuel in the cylinder will occur too soon and tend to force the piston down while it is still traveling up. This causes pre ignition or -knocking and pinging-. If the ignition spark is set too far retarded, or after TDC (ATDC), the piston will have already started on its way down when the fuel is ignited. The piston will be forced down for only a portion of its travel, resulting in poor engine performance and lack of power.
Timing marks or scales can be found on the rim of the crankshaft pulley and the timing cover. The marks on the pulley correspond to the position of the piston in the No. 1 cylinder. A stroboscopic (dynamic) timing light is hooked onto the No. 1 cylinder spark plug wire (2.2L engine only, on the 2.4L engines, special adapters are needed) . Every time the spark plug fires, the timing light flashes. By aiming the light at the timing marks while the engine is running, the exact position of the piston within the cylinder can be easily read (the flash of light makes the mark on the pulley appear to be standing still). Proper timing is indicated when the mark and scale are in specified alignment.


WARNING When checking timing with the engine running, take care not to get the timing light wires tangled in the fan blades and/or drive belts.

The engines covered by this manual are equipped with distributorless ignitions, ignition timing is controlled by the Powertrain Control Module (PCM), as applicable. No adjustments are possible. If ignition timing is not within specification, there is a fault in the engine control system. Diagnose and repair the problem as necessary.




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SOURCE: car stalls when stopped, cuts out when accelerating to HWY spds.

You could have a bad or intermittent fuel pump. Not a cheap thing to have.

An OBD 2 scanner can read fuel pressure on the drive to see if your fuel pressure drops off at odd times to confirm. It can also tell if there are transcient vacuum leaks at idle which the engines idle air control cant compensate for.

Do the plugs, wires and cap too.

SOURCE: 90 chevy k1500 350 tbi fuel problem starts but wont stay running

try bypassing the oil pressure switch on the back of the block behind the distributor, if there oil pressure switch goes bad it will do this. had one that drove me nuts trying to fix it then figured out I had to buy a book and low and behold thee it was 3 wire oil pressure switch you can't see between the engine and fire wall just behind the distributor and costs 8 bucks to buy new.

SOURCE: 2000 Chevy S10 starting problem

You don't have a carburator. The last carb was on my 1984 S-10 Blazer,which by the way ,I've had 26 years.
Why are you questioning a professional,who's help you asked for. Sounds like a fuel pump to me.