How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Kenny Your Own Question
Kenny, ASE Certified Technician
Category: Chevy
Satisfied Customers: 227
Experience:  Providing 16 years of experience with certifications in engine performance, electrical and brakes
Type Your Chevy Question Here...
Kenny is online now
A new question is answered every 9 seconds

99 chevy suburban: idles rough..cap and rotor..distributor

This answer was rated:

bought 99 chevy suburban w/ vortec 5.7 350 , engine idles rough and codes were random misfire, replced cap and rotor and noticed wire harness for distributor not plugged in. the wire harness does not match the distributor plug and the harness will only reach to the distributor. i made an impression of the female connection on the distributor and the prongs are 3 straight across and the male connector has 2 on top and 1 underneath to the side with a notch to only be able to put on one way. I'm thinking wrong distributor or wrong harness. Is their a picture to compare what the correct female connection on the distributor should look like
I will try and locate the picture of the distributor connector for you
The connector for the distributor is a black connector with three wires. A pink and black wire, brown and white, and a pink wire. It is a simple three circuit connector. I hope this helps but if not let me know what color the connector is that you have and how many wires and I can tell you what it is for.
Customer: replied 7 years ago.
after looking at the wire with a flash light, it acyually is one yellow wire but the harness has 3 prongs. Not sure what would be causing random misfire code 0300
Is your distributor plugged in now with the correct connector. If so now you will need a scanner to watch the ignition spark advance when you start the engine. This should be at 0 and if it is not it can cause a check engine light and a rough idle. After seeing what number it is with a scanner you can loosing the bolt that holds the distributor and turn the distributor a little then check the scanner again and start the engine. Do this until the spark advance is at 0. If this is not done after replacing the distributor then engine will not run smooth at idle.
Customer: replied 7 years ago.
the wire you mentioned is already connected. I removed the code and started the engine and the same code came back about three minutes after starting and letting it run.
What is the code?
Customer: replied 7 years ago.
Are you sure the plug wires are on properly and not crossed?
Customer: replied 7 years ago.
I put the wires on the cap one at a time from the old cap so not to cross them. when I changed the plugs, had a code 0305 (#5 plug misfire detected) that prompted me to put new plugs in.
If you had a p0305 when you started then this is most likely your problem. When a code like the p0305 appears and not just the p0300 then this is a control circuit issue which means it is a component that is causing a misfire. If you have good engine compression is could be your #5 fuel injector, the wires coming from your computer and going to the #5 fuel injector, are the computer itself. It may be the #5 fuel injector causing the misfire. The poppet valves inside the fuel injectors are known to get stuck and cause a misfire in these engines.
Customer: replied 7 years ago.
sorry to bother you further but can this also cause he o2 sensor to code also
Yes a misfire code can not only cause the o2 sensor code but can also damage the sensor if the misfire is not fixed.
Kenny and 4 other Chevy Specialists are ready to help you