kar120c Posted September 5, 2011 Share Posted September 5, 2011 Damn Jeep is really starting to piss me off, at wits end. In the morning or evening when the temperature is around 60 degrees, the motor will not start. I can crank all day and it never starts. Soon as the outside temperature warms up to about 80, the jeep turns over quickly on first try. CPS is new and I already tested the coil and CTS with an ohm meter, both were within spec. Any ideas? :( Link to comment Share on other sites More sharing options...
kar120c Posted September 9, 2011 Author Share Posted September 9, 2011 BUMP Link to comment Share on other sites More sharing options...
jimoshel Posted September 9, 2011 Share Posted September 9, 2011 Are you getting spark? Being Oregon the first thing I would suspect is moisture, condensation in distributer as first suspect. The spark is going to take the route of least resistance and that will be moisture covered wires, insulators, etc. Try a shot of ether in the intake. When I was living in North Bend I had a '62 Austin Healy 3000. It was really sensitive to moisture. The only way I could count on it starting in the early morn was by putting a light bulb, 60 watt, under the hood and leaving it on all night. Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 9, 2011 Share Posted September 9, 2011 Assume you are referring to the 91 MJ? Have you checked if it's throwing a code using the key sequence? http://www.comancheclub.com/forums/viewtopic.php?f=9&t=29857 Link to comment Share on other sites More sharing options...
kar120c Posted September 9, 2011 Author Share Posted September 9, 2011 I thought moisture as well but cap is dry as a bone. I just tried to fire it up and it spit & sputtered, I had to rev it to 3k for a few seconds then it idles fine. Still pretty cold this morning though, sun hasn't come out yet. Link to comment Share on other sites More sharing options...
Kernel Posted September 9, 2011 Share Posted September 9, 2011 fuel filter... when was it last changed? Link to comment Share on other sites More sharing options...
kar120c Posted September 9, 2011 Author Share Posted September 9, 2011 Put a new fuel filter in less than 500 miles ago. 35psi at idle, 40psi with vaccuum disconnected which is in spec according to my manual. Anyways this morning the weather warmed up, jeep started fine. Drove it for about 30 miles with no problem. Got home, shut it down. Came back out 30 minutes later and it wouldn't start again. After about 7-8 tries it started fine. This is driving me nuts. Almost everything in the engine compartment new except for: coil (slightly out of spec, book says 1.2-1.4ohms, reads 1.5ohms) coil pickup inside distributor IAC coolant temp sensor manifold air temp sensor All those items are about $40 ea at the local parts store, trying to avoid just throwing more money into an unknown problem. Link to comment Share on other sites More sharing options...
Kernel Posted September 9, 2011 Share Posted September 9, 2011 35psi at idle, 40psi with vaccuum disconnected steady or flutters. Link to comment Share on other sites More sharing options...
Kernel Posted September 9, 2011 Share Posted September 9, 2011 liquid lunch has me quoting myself. Link to comment Share on other sites More sharing options...
Kernel Posted September 9, 2011 Share Posted September 9, 2011 :dunno: Link to comment Share on other sites More sharing options...
Kernel Posted September 9, 2011 Share Posted September 9, 2011 not saying it's your fuel pump. my rig would never not start just took longer and longer. i ran around with a pressure guage attached to the fuel rail and found a pattern. there ended up being a crack in the top of the fuel pump. it ran at pressure but would flutter to 31-34psi. edit: it also (the pressure) would drain off purdy quick after shut down. Link to comment Share on other sites More sharing options...
kar120c Posted September 9, 2011 Author Share Posted September 9, 2011 It bounces wildly at 35, hard to tell what the exact reading is. I'll try a pressure leakdown test too. Link to comment Share on other sites More sharing options...
kar120c Posted September 9, 2011 Author Share Posted September 9, 2011 Looks like my pressure is dropping 5psi every minute. Books says 20psi after about 30 minutes is normal but I'm almost there. So it looks like a new fuel pump is in order then. Link to comment Share on other sites More sharing options...
Kernel Posted September 12, 2011 Share Posted September 12, 2011 ding, ding, ding, winner... until you fix it and it doesn't cure the problem. :brows: have done this a few times :ack: Link to comment Share on other sites More sharing options...
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