Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Reinstalled Engine cranks but wont fire


Recommended Posts

2002 996 Carrera 3.6L

I dropped the engine/tranny. I needed to fix an oil fill tube and a rear left side wire harness issue. Car ran before the work. I now have the engine/tranny back in the car. I dont have the transaxles hooked up or the clutch bleed. The rear of the car is still up on stands. I wanted to try and start the car before reassembling everything. Well the car turns over but will not fire. The only idiot light that comes up on the dash is a temp sensor failure or something like that. I went back through the book and I seem to have everything hooked up. I know a motor needs four things to fire air, fuel, spark and compression. The fuel pump can be heard upon turning the key on. I get fuel to the connection on the top left side of the motor. The air box is removed. One thing I havent checked was spark. The spark plugs where change less than a month ago and it ran before. I dont recall removing anything that would remove the spark. Is there a connection at someplace that removes that from the coils that I could have disconnected.(I will check spark tomorrow).
Sorry guys I am really searching here. Not sure what exact info you all would need. The car has been sitting for about 3 weeks no fuel or power. Any suggestions onthungs to look for or try would be very helpful.

Ask for any info you may need and ill do my best to provide it. Thanks.

Edited by SLC911
Link to comment
Share on other sites

Can you explain a little more as to the harness issue?

There was a short caused by the license plate light wires. It melted wires through the harness, that I fixed by splicing. Which brings up the question of if the O2 sensors are not connected properly would that prevent the car from firing? :huh:

Edited by SLC911
Link to comment
Share on other sites

No, the O2 sensors will not prevent the engine from firing. However, a bad coolant temp sensor reading may change the air/mixture so much that the engine won't fire up. If you do have sparks, I would check the coolant temp sensor and MAF connections.

If you do not have sparks, I would check the connections on the throttle body, crank position sensor, and cam sensors.

Link to comment
Share on other sites

No, the O2 sensors will not prevent the engine from firing. However, a bad coolant temp sensor reading may change the air/mixture so much that the engine won't fire up. If you do have sparks, I would check the coolant temp sensor and MAF connections.

If you do not have sparks, I would check the connections on the throttle body, crank position sensor, and cam sensors.

Where is this coolant temp sensor located? How many MAF sensors are there, I thought just the one that goes into the air box?

There are 4 bolts and one electrical connection to the throttle body.

Link to comment
Share on other sites

If the pulse sensor for the flywheel is faulty the fuel pump will not continue to run and the engine will not start. This is a pretty common problem. It happened to me once when I had my engine out. The fuel pump will run when you turn the. Key on so this can be deceiving. Check the signal from the sensor.

Link to comment
Share on other sites

The idiot light is a thermometer temperature display with the words "failure indicator"

I did a quick shot is starting fluid it acted like it wanted to fire but didn't. Not sure where that leaves me.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.