01-30-2011, 05:13 PM
Join Date: Apr 2010
Originally Posted by thowild
I need help with starting problems on my 1989 Jeep Wrangler, 258 inline 6.
It will start when cold, or when hot - typically. Not when warm. If I wait a few minutes after it is running to try and restart, it will turn without cranking.
It appears the choke plate stays closed when it doesn’t start. Mainly from reading this post (http://www.carkb.com/Uwe/Forum.aspx/jeep/9932/87-wrangler-starting-problem-HELP), I learned that sticking a screwdriver to hold the choke plate open will allow it to start.
Fuel delivery: replaced fuel pump, filter x2, plenty of gas reaches the carb, replaced the gas to rule out water
Ignition: spark at the plugs ever time I have checked. Replaced ignition coil, rotor, distr cap, and the ignition module was replaced about 18 months ago.
Starter, Battery and Alternator all perfect.
Vacuum: fixed 3 leaks in my vacuum hoses. One tube to the vacuum reservoir was disconnected. Hole in the tube to the sol-vac solenoid (this helped idle RPMs but not the start problem), and one tube from the charcoal canister to my gas tank vent. Also, I have plugged the air purge system due to old rusted pipes to the exhaust.
I replaced the carb with a rebuilt model about a year ago. I assume all the adjustments on the carb are okay. I replaced the choke pull off as well again and no fix.
I have been unable to replace my 02 sensor (stripped) but when I disconnect it there is no additional problem.
? MCU (microcomputer unit) is at the top of my list – is this a possibility?
? Ignition Module defective again
? Electric choke defective?
? undiagnosed vacuum leak or clog or solenoid bad
Thanks in advance,
Ignition module can go bad. The same happen to me. It took 6 months for the new module to go bad.