grabber Posted April 17, 2011 Share Posted April 17, 2011 Before you have a Idea please read. I have replaced the following parts, Crank sensor has nothing to do with starting, Water temp to ECU, Air Temp, Injector, Starter SW has signal to ECU pin 29, ECU, Throddle Position sensor is set per manual. fuel pump and filter replaced, fuel pump bypassed fuel relay ( runs full time and have good pressure at TBI) Fuel relay show it connect a signal to the Injuctor will check it today. Not sure all Signal need to ECU to get Injector to Prime. But if I give a shot of starter fuel It will start and run. Link to comment Share on other sites More sharing options...
64 Cheyenne Posted April 17, 2011 Share Posted April 17, 2011 Seems you have done a lot already, have you checked and cleaned the grounds? Batt to block, block to body and the one behind the left tail light? If your experiencing electrical or fuel problems such as this, the grounds should be the first thing you eliminate. Link to comment Share on other sites More sharing options...
JeffN Posted April 17, 2011 Share Posted April 17, 2011 put a noid light on the injector plug in and make sure you are getting an injector pulse from the ecm Link to comment Share on other sites More sharing options...
deziped Posted April 18, 2011 Share Posted April 18, 2011 Maybe bad gas/water in tank/plugged air filter. Water in gas kept mine from starting but with a shot of help it would run all day if I kept it off idle, weird stuff happens. Dumped in about three cans of HEET (I think) to absorb water and with full tank of fresh gas haven't had any more problems. Link to comment Share on other sites More sharing options...
johnj92131 Posted April 18, 2011 Share Posted April 18, 2011 OK, I am an old fart. Last time I had something like this problem was with a 66 Chevy. The points were collapsed and would not allow a spark, so the car did not fire. I had to use starting ether to get the engine to run. This was in 1973 and I was stuck in the worst possible part of Chicago. My wife asked the Gas Station Attendant where the bathroom was. He pointed around the corner. The guy saw her reaction and said: "Don't worry, lady, I have a gun." We got out of that part of Chicago, ASAP and have not been back since!!! Your problem sounds like a lack of fire. I filled my 2000 Rodeo with E-85 and had hard starting problems, ran like total crap. Finally burned enough of the E85 to add some RUG and the car started to run better. I filled up later with an other 5 gals of RUG and was soon back to normal. First, check your spark at the plugs. Link to comment Share on other sites More sharing options...
grabber Posted April 19, 2011 Author Share Posted April 19, 2011 It has nothing to do with the fuel, Order a light to check the injector, I believe I'm missing a input to the ECU for the prime pulse, pulled fuel relay and it died OK, Pull Throttle Position, NO Change, ran. Read on JeepForum the the fuel pump wiring hooked up backwards will stop it from starting, but will run after a shot of starter fuild. :huh???: anybody heard of that? Link to comment Share on other sites More sharing options...
grabber Posted April 20, 2011 Author Share Posted April 20, 2011 Found out that the starter switch has a dk grn to the starter sol, it should have a grn/whit to pin 29 of the ECU for the start signal. Their is no grn/wht connection. aslo can't id pin 29 of the ECU the 35 pin out has a mark on pin 2 but the unused pins on 9 and 20 don't match. Link to comment Share on other sites More sharing options...
jmderyke Posted April 20, 2011 Share Posted April 20, 2011 There is also another guy on here having the exact same problem as you on post "won't start this morning" I will get him to come onto your post here. It will start with some fluid and once it starts it will run until next time you try to start it. He said at first there was no spark so I showed him how to test his ignition system, now he says theres spark but needs starting fluid to get it started. What year is your tbi sounds like 86-88? So its gotta be the ecu either isnt getting a good signal from sensors or to injector, or the ecu can be bad. Since you put on a new cps did you happen to see flywheel condtion? Maybe it just has some grime built up on it and the cps can't get a good signal. just a thought Link to comment Share on other sites More sharing options...
Sutek Posted April 21, 2011 Share Posted April 21, 2011 Hey I am having this exact same problem I have replaced just about everything you have as well. It runs great once I get her started and all that takes is a quick spray of starter fluid and she fires right up. Have you made any progress on this issue? or have any ideas? No one else had this problem? Link to comment Share on other sites More sharing options...
grabber Posted April 21, 2011 Author Share Posted April 21, 2011 did work out it last night, storms. but it looks like pin 29, start signal, ECU pin not right. maybe tonight Link to comment Share on other sites More sharing options...
NewfieMJ Posted April 21, 2011 Share Posted April 21, 2011 Grabber , no mention of changing the coil ? I know you have spark , question is , how much . A weak coil can run an engine but will have issues with starting . The strater fluid has a high combustion rate so it burns easy . Once running , the compressed gas will ignite easy with minimal spark . Not sure , just sounds like it might fit your bill . Link to comment Share on other sites More sharing options...
91coMANche Posted April 21, 2011 Share Posted April 21, 2011 Could you put the year and model of your MJ in your profile. That will help us help you. Link to comment Share on other sites More sharing options...
jmderyke Posted April 21, 2011 Share Posted April 21, 2011 good idea newfiemj, maybe check your coil sutek since you did have spark for a little while, just use those pics I posted in "won't start this morning" post... I wrote the specs right by the pictures. Link to comment Share on other sites More sharing options...
grabber Posted April 22, 2011 Author Share Posted April 22, 2011 Open ECU to figure pin out and have starter signal on pin 29, noid light should be in today, Have battery @ injector. So I beleive Its a different signal nissing now to get prime oulce, But I'm clue less. Link to comment Share on other sites More sharing options...
grabber Posted April 22, 2011 Author Share Posted April 22, 2011 I also have a new coil, cap and rotor Link to comment Share on other sites More sharing options...
grabber Posted April 22, 2011 Author Share Posted April 22, 2011 Its a 86 custom, long bed with a 2.5 l Link to comment Share on other sites More sharing options...
grabber Posted April 23, 2011 Author Share Posted April 23, 2011 Well I have injector signal durning crank, no arking from wires or coil, Going to check timing in the am, can't remember if I did it, and also have a different coil pack to go in. Link to comment Share on other sites More sharing options...
SW86 Posted April 23, 2011 Share Posted April 23, 2011 I'm worthless to you on your issue but i still want to come see those MJs!! you live so close its hard not to want to :nuts: Link to comment Share on other sites More sharing options...
Sutek Posted June 22, 2011 Share Posted June 22, 2011 Did you ever figure this issue out? Link to comment Share on other sites More sharing options...
grabber Posted September 11, 2011 Author Share Posted September 11, 2011 To hot most of summer, had other thing going on, starting back up Link to comment Share on other sites More sharing options...
Recommended Posts
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 accountSign in
Already have an account? Sign in here.
Sign In Now