My 2008 chevy aveo bogs down when you are excellerating or going up a steep hill and if you back off just a little on the throttle is smooths right out and run fine. also some times when you are holding the throttle at a steady speed , it will start jerking but again if you back off it will straighten out. I checked the fuel pressure and it has a staedy 58 pounds. Today was checking the spark on the coil pack and noticed that while all 4 wires have spark some are a lot stronger them others. is this a sign of a back coil pack ? Thanks

SOURCE: 1987 Chevrolet S-10 Pickup1987 chevy s10 2.5l tbi

Check the trottle body postioning sensor...

SOURCE: 1987 chevy engine problem

you have to reset base idle see manual at library for procedure

SOURCE: 1987 chevy S10 engine idle problem

relace the throtle air idle valve.The temp switch will allso cause this problem.

SOURCE: 2007 aveo misfire faults

gm has a problem with this from way back. double check your spark plugs and if they are not ac delcos, change them. ive seen this time and time again swearing, myself, that there is no way that the plugs would cause this issue. it always comes up with random misfire and usually another 1 or 2 codes misfire codes. put in ac delco, no more codes. let me know

Ben Darden

• 984 Answers
• Posted on Jun 24, 2011

SOURCE: have a 1998 chevy silverado

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WARNING! I'm sometimes accused of not giving short answers. However, my philosophy is that too much is better than too little.

Still with me?

This is how your problem is researched in my shop. 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 pressure regulator or water in the fuel tank.

My second area of concern would be the manifold pressure sensor which is located under the hood, center, rear engine area, above valve cover, mounted in bracket. However, you must remember that these are nothing more than starting points and not guaranteed solutions at this preliminary stage.

First a little background 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. The fuel pressure regulator has screen that can be removed with a small pick if it is dirty and appears to be clogged. Removing the screen will not affect the operation of the regulator.
• 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.


Whenever your engine cranks but does not start, runs rough, staggers, sags or cuts off, follow this Troubleshooting Guide. Some of these steps require a code scanner. They are costly but AutoZone will loan you one for FREE.

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 - borrowed from AutoZone - is needed to identify any system trouble. Use this easy-to-use 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.


NOTE: 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.

If you have trouble using the code scanner or interpreting the codes click on the following link and use my access code (carrepair): Free Automotive Repair information for Users of a Code Scanner

All the best

Ben