Q: Trouble starting and acceleration bogs down

asked by on

My truck is having a lot of trouble starting and it bogs down when I accelerate from a stopped position. When it idles, it is a bit higher than normal. Another problem is the shifting which is very hard to shift between gears. I have replaced all of the sensors and also the fuel filter. Would you give me advice on what I should do next to fix my truck's starting problem?

A: Hello there, thank you for asking about you...

Hello there, thank you for asking about your 1986 GMC S15. You don't say whether you have an automatic or manual transmission, so I'm not sure how to help you with your shifting concern. As far as the engine performance problem goes, the first place I would look would be the idle air control valve (IAC). The IAC allows a small amount of air to bypass the throttle to control idle characteristics. If the valve is faulty, the engine may not get enough air and stall. Other potential causes for your concern include, but are not limited to, vacuum leaks or a faulty sensor. There are too many potential causes to list, so I suggest you have your vehicle inspected by a professional. A certified technician from YourMechanic can come to your home or office to diagnose your shifting problem and replace the idle air control valve if necessary.

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: No power when accelerating

Hello! I believe the problem is likely to do with the mass air flow sensor. When this sensor is at fault it will be sending a regular error inlet reading which will cause computer to incorrectly apply air fuel ratio....

Q: Engine idling and check engine light on

Carbon build-up on the intake valves is a common issue on the IS250. Lexus recommends to remove the valves and clean them while other manufacturers use anything from an intake cleaning solvent to sandblasting using walnut shells to remove the...

Q: 20 amp ignition fuse continues to blow

Hello. All of this depends on what was spliced into that circuit when the engine was swapped out. I usually isolate this problem by disconnecting the circuits in it until it no longer blows. This fuse usually has a problem...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...