Sutek Posted April 10, 2011 Share Posted April 10, 2011 What I have is a 1986 4x4 comanche with a Renix 2.5L. Problem: Won't start without a shot of starting fluid or pumping new gas in it. Just turns over without any signs of attempting to fire. There is a spark. Runs great once started. Doesn't miss a beat. The wires are in the correct firing order, battery is fully charged. Starter is brand new, cps new. The distributor cap and rotor are new. I checked to see if there was spark from every wire with a screw driver and there was a spark. :wall: Update as of 4/19 It will start and run with a shot of starter fluid and will continue to run on its own once started. If i turn it off it will not start again until it gets that shot of starter fluid again. Update June 22 Fixed her self for 2 months and now won't start with out a shot of starting fluid or at the gas pump again. Update October 3rd She will start on her own when I pump gas in it, leads me to believe the gas tank may just be dirty? Link to comment Share on other sites More sharing options...
mnkyboy Posted April 10, 2011 Share Posted April 10, 2011 It should start without that,have you checked for spark and fuel? Maybe try pouring a little gas in the TB and see it it trys to fire Also when you ask something like this give more info on your truck,I can tell its a Renix 2.5L but others may not. Link to comment Share on other sites More sharing options...
Sutek Posted April 10, 2011 Author Share Posted April 10, 2011 You're absolutely right, my bad I know better than to not state what exactly it is I have.. Ok then what does that thing in my picture do then? Is it like a choke or something? Even if it isn't the reason it won't start it is seated and wasn't 2 days ago so it must be broken. As for the checking for spark and all that I haven't gotten to it yet. I found out she wasn't starting when I was going to leave for work. I noticed that thing seemed seated then took the picture posted this thread and my ride showed up. I am going to try and mess with it more tonight. Link to comment Share on other sites More sharing options...
jmderyke Posted April 11, 2011 Share Posted April 11, 2011 That thing in the picture controls engine idle, it just opens or closes the throttle body slightly to keep the idle around 800rpm when hot and a little higher when the engine is cold. It will run without that part. Link to comment Share on other sites More sharing options...
Sutek Posted April 11, 2011 Author Share Posted April 11, 2011 Well I am not getting a spark from the spark plugs. So I checked the wire off the coil and nothing as well. I guess it is either my coil or my crank shaft sensor? I tried unplugging and plugging the sensor back in (read that might reset it and give me one last start) this changed nothing. What plugs into the slot closest to the windshield on the coil? I have nothing there at all except an open space. Link to comment Share on other sites More sharing options...
jimoshel Posted April 11, 2011 Share Posted April 11, 2011 Nothing. It's not used. It's just there. Remove the connector from the coil closest to the front of the truck.It's a 3 pin. The rearmost pin should read +12VDC. This is the input voltage to the coil. Link to comment Share on other sites More sharing options...
Sutek Posted April 11, 2011 Author Share Posted April 11, 2011 Well that is good news, I have a lot of "it's just not used" spots in this old truck. I am pretty sure my issue is the cps. I don't know if it's just that it only cost 20-30 so wishful thinking or if I have just read too much about the cps but either way that's what I think it is. Unless someone says otherwise or has any other ideas for me to test before my ride gets here in a couple hours I am just going to replace it and hope she starts. Link to comment Share on other sites More sharing options...
jmderyke Posted April 11, 2011 Share Posted April 11, 2011 do you have a multi meter? or know someone that does? the cps is usually the problem child of the ignition electrical system you need to test it. try tapping it, if you don't have multi meter sometimes that will make a connection in the cps Link to comment Share on other sites More sharing options...
jimoshel Posted April 11, 2011 Share Posted April 11, 2011 A lot of the time that's all it is. I have a '89 with the 2.5 engine. Often times it won't start and I just disconnect and reconnect the CPS connector. It starts everytime. The pins get a little corroded and the wiping action cleans them. Link to comment Share on other sites More sharing options...
Sutek Posted April 11, 2011 Author Share Posted April 11, 2011 I do not have a meter it's out at my folks house which is about 30 miles away. I tried unplug and replug but no luck. Did a lil wiggling on it and nothing but I am still pretty sure that is my problem. If it isn't it will save me trouble down the road anyway is what I am telling myself. It seems to make sense though with the difficulty starting then not being difficult then being difficult for 2 months. Also it all worked just fine the night before then BAM nothing. I went ahead and called the parts store to get my sensor sent over from another store. Link to comment Share on other sites More sharing options...
Sutek Posted April 11, 2011 Author Share Posted April 11, 2011 alright, so I changed out the CPS and now I have a spark coming from the spark plug wires now but still not starting. I checked on the fuel flow in the engine bay and it sprayed out just as it should. I am sorta at a loss as to what the next step should be. Also anyone know what size socket is needed to get at these spark plugs. None of mine seem to be able to fit. Thoughts? ideas? questions? Link to comment Share on other sites More sharing options...
jmderyke Posted April 12, 2011 Share Posted April 12, 2011 well if you have fuel, then you said you have spark at your wires then it must not be reaching the plugs double check your wires connections from the coil and cap. are the wires in the correct firing order? And for the life of me I can't remember the spark plug size I always use one of my deep socket set. Link to comment Share on other sites More sharing options...
jmderyke Posted April 12, 2011 Share Posted April 12, 2011 was the injector spraying? or did you just disconnect the fuel line and turn on the ignition key? Link to comment Share on other sites More sharing options...
Sutek Posted April 12, 2011 Author Share Posted April 12, 2011 I did not test the injector. I have never worked on an engine that didn't have a carb or two on it so I am a bit intimidated by all that witchcraft. Not sure how to go about checking it. The wires are in the correct firing order, battery is fully charged. Fuel pump is fine, fuel filter is good. Starter is brand new, cps new. The distributor cap and rotor look new. I checked to see if there was spark from the number 1 wire with a screw driver and there was a spark. Link to comment Share on other sites More sharing options...
jmderyke Posted April 12, 2011 Share Posted April 12, 2011 well you can either put a little gas or starting fluid through the throttle body to see if she will fire up..... or you can jump the injector with 12v tapping one connection on the battery listening and watching to see if injector is working..... like testing a solenoid Link to comment Share on other sites More sharing options...
Sutek Posted April 12, 2011 Author Share Posted April 12, 2011 I will try both tomorrow morning. Where would you recommend I get the 12v from? Link to comment Share on other sites More sharing options...
Sutek Posted April 12, 2011 Author Share Posted April 12, 2011 I tried pouring a lil gas in and nothing but right after that I started messing with a spark plug and it look a bit orangish burnt I tried to start it just to see if it would fire and the engine tried to start so I put the plug back in and tried again and it started. I then turned it off again cause I saw a minor gas leak. I tightened that up and stopped the leak and started it again no problem. I got excited cleaned my tools up tried to figure out what I did and moved the truck. Turned it off and just for fun tried to start it again. It won't start.. Sounded great while she was running though. Link to comment Share on other sites More sharing options...
Sutek Posted April 13, 2011 Author Share Posted April 13, 2011 Which post do I tap with 12 volts on the injector? I am pretty sure that has to be it. It seems to stay bone dry in there. I had my girlfriend try and start it while I watched and I didn't see or smell any sign of gas. I want to test it before I get another. Can't really afford the 125 bucks right now if it isn't the actual problem. Link to comment Share on other sites More sharing options...
jmderyke Posted April 13, 2011 Share Posted April 13, 2011 I tried pouring a lil gas in and nothing but right after that I started messing with a spark plug So I honestly believe you have a bad connection somewhere in your electrical for example like your sparkplug wire from your coil to distributor but I will show you how to test your injector. Ok you said you have fuel pressure and spark so test your injector (they hardly ever go bad fyi) connect one lead to +12v and TAP your negative on your battery terminal (DO NOT HOLD IT) and listen for small clicks coming from your injector. No fuel will come out so don't worry if its not If the injector clicks then you need to check power coming from your ecu, at the injector wires while cranking engine. You will need a multi meter, if you don't have one, barrow one or buy one, you WILL use it many times over and it will pay for its self. Link to comment Share on other sites More sharing options...
Sutek Posted April 14, 2011 Author Share Posted April 14, 2011 Yeah i was thinking the same. I mean it doesn't make much sense that it would start out of no where then not if it was an injector and I am certain it wouldn't have been able to drive around. I changed my plug wires including the one from the coil thinking maybe one of the plugs were grounding out. How ever it does seem to consistently get a spark. I will try testing the injector but I agree i highly doubt that will be the problem. Thank you very much jmderyke. Is there a part that makes it spray before it is running? Cause it would make sense if it wasn't spraying until it was actually running, maybe the gas I poured in started it and the injector took over after? Link to comment Share on other sites More sharing options...
Sutek Posted April 14, 2011 Author Share Posted April 14, 2011 I tested the injector and it clicked just as you said it would. I am going to get a meter to test its plug tomorrow. Any more ideas? Sensors or something? Link to comment Share on other sites More sharing options...
jmderyke Posted April 14, 2011 Share Posted April 14, 2011 You will save a bunch of money buying a good multi meter and a good manual. so if i can find time tomorrow i will post some pics and how to test your ignition system. you will need a multi meter and hopefully we can get you back on the road tomorrow! :cheers: Link to comment Share on other sites More sharing options...
Sutek Posted April 14, 2011 Author Share Posted April 14, 2011 Sounds like a plan, Oreillys isn't a far walk at all. I'll get down there tomorrow morning. Thanks a lot for the help man. Got the meter and tested it. As you called it. She read 3.63 so the problem is else where. Also checked the coil input it read 11.6 Link to comment Share on other sites More sharing options...
jmderyke Posted April 14, 2011 Share Posted April 14, 2011 no prob! give me a few I'm going to post some pics Link to comment Share on other sites More sharing options...
jmderyke Posted April 14, 2011 Share Posted April 14, 2011 Ok first use a known good spark plug and use it to see if you have spark, If no spark check and make sure your cap and rotor are in good condition, then check ignition wire from coil to distributor cap, if no connection = bad if high ohms = good ok if everything looks good check your crankshaft position sensor (or called top dead center sensor) look at the connector to ensure its making good connection and no dirty prongs, check the resistance... it should have high ohms like in picture, if its ofl (no connection) or a low value for example 2.8 ohms its bad If thats good check AC voltage, leave the test leads in same position just switch your multi meter to v~ go inside and crank the engine, you should get a reading that jumps all around, if you get nothing its bad. If your cps is good check your coil, remove it from your ignition control unit. first test should have no connection ( ofl ) Then next test should be with in 0.2-0.8 ohms Then your last test should be around 2500 - 5000 ohms If coil is good check power to ignition control module, connect like shown switched to DC volts then turn ignition switch on you should get close to battery voltage, then crank engine, while cranking no lower than 9.5v. If that test is good then its prob your ignition control module, manual says you need a special tester for that I don't have one so I use a spare from a donor cherokee ( or find one from a junk yard) Hope this helps! I will check in later good luck! Link to comment Share on other sites More sharing options...
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