gilman711 Posted May 3, 2018 Share Posted May 3, 2018 I'm at a loss and need some help and forums have always been a great source to give and receive such knowledge. To clarify I did not install all these parts to try and correct no start issue but even new parts have been tested as some were installed before me buying. I bought truck not running. 1989 Comanche 4.0 Renix Manual Trans Crank No Start Issue New Battery New Fuel Pump New Fuel Filter New Injectors New Starter New Plugs New Engine Ground 4Gauge Cable New Air Filter New Distributor Cleaned TB and TPS (calibrated TPS) Cleaned CPS (crank sensor) (tested ok) Cleaned Coil Contacts Checked Firing Order Vehicle cranks well and sometimes tries to start and fails and other times just seems to crank and crank. I've tested CPS and TPS and both within specifications. I have 38psi Fuel Pressure when cranking. I have spark as well and visually appears to be strong spark. Attached a picture of a connector on passenger side of engine bay I'm not sure what it connects to? What else can I check or test? Thank you so much in advance!! Link to comment Share on other sites More sharing options...
Eagle Posted May 4, 2018 Share Posted May 4, 2018 You have spark, but do you have spark when and where you need it? Is it possible the previous owner got the distributor in 180 degrees out of phase? That would mean #1 is "firing" when it's at the top of the exhaust stroke rather than the compression stroke. Link to comment Share on other sites More sharing options...
Pete M Posted May 4, 2018 Share Posted May 4, 2018 yup, the computer controls the timing but can only accommodate a small amount of distributor misalignment or timing chain misalignment. Link to comment Share on other sites More sharing options...
DirtyComanche Posted May 4, 2018 Share Posted May 4, 2018 Will it run on starting fuel or with gas dribbled down the TB? Rule out if it's ignition or fuel. Injector harness could be on wrong, which sucks. But I'd say more likely the disty is indexed wrong. Link to comment Share on other sites More sharing options...
Ωhm Posted May 4, 2018 Share Posted May 4, 2018 2 hours ago, gilman711 said: Attached a picture of a connector on passenger side of engine bay I'm not sure what it connects to? Find that connectors mate. It can't be too far away. Unable to tell if you're showing the Engine Harness side connector or the Engine Control side harness connector, either way, find its mate. Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 48 minutes ago, DirtyComanche said: Will it run on starting fuel or with gas dribbled down the TB? Rule out if it's ignition or fuel. Injector harness could be on wrong, which sucks. But I'd say more likely the disty is indexed wrong. Will not run with fuel down TB. Injector harness would be harder to mess up than say ignition wires. I'm going to check distributor tomorrow Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 25 minutes ago, Ωhm said: Find that connectors mate. It can't be too far away. Unable to tell if you're showing the Engine Harness side connector or the Engine Control side harness connector, either way, find its mate. Haha I searched and searched and cannot find it anywhere. I looked on either side of engine and even possibly on transmission. Link to comment Share on other sites More sharing options...
DirtyComanche Posted May 4, 2018 Share Posted May 4, 2018 1 hour ago, gilman711 said: Will not run with fuel down TB. Injector harness would be harder to mess up than say ignition wires. I'm going to check distributor tomorrow It's actually incredibly easy to put the injector harness on wrong. No, I've not done it, but I've dealt with trying to troubleshoot it. Link to comment Share on other sites More sharing options...
cruiser54 Posted May 4, 2018 Share Posted May 4, 2018 TEST your CPS http://cruiser54.com/?p=50 Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 Attached picture of injector harness. How would one go about determining if they are in correct location? Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 34 minutes ago, cruiser54 said: TEST your CPS http://cruiser54.com/?p=50 I used that sight to test CPS and it was good. It's a great resource! Link to comment Share on other sites More sharing options...
Jeep Driver Posted May 4, 2018 Share Posted May 4, 2018 Index your distributor. BTW....... You have a cam position sensor in that dist, right? Others have reported a similar problem and it was the sensor or dist. Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 Pictures show it at TDC and where the Rotor is in relation to #1 cylinder which appears to be lined right up with it. According to the Cruiser54 regarding Cam Sensor: "For clarification though, that’s not a cam sensor inside the Renix dizzy. It’s there to fire the injectors sequentially with the firing order. You’ll never notice if it went bad because the ECU will try to “guess” where it is and does a heck of a job at it. " Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 I'm wondering if possibly the sensor is bad in distributor and it's just firing injectors randomly? Anyway to test? Link to comment Share on other sites More sharing options...
Ωhm Posted May 4, 2018 Share Posted May 4, 2018 Look for path to ground at the sync sensor (C231_A harness side). If missing 4 pin connector is C109, then no path to ground. Added: You still need to determine if Cyl #1 is on compression stoke or exhaust stoke. Your pictures don't prove that. Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 37 minutes ago, Ωhm said: Look for path to ground at the sync sensor (C231_A harness side). If missing 4 pin connector is C109, then no path to ground. Added: You still need to determine if Cyl #1 is on compression stoke or exhaust stoke. Your pictures don't prove that. I held my finger on cyl 1 when rotating engine to verify it was on compression stroke. Is the Sync Sensor the one in the distributor? Link to comment Share on other sites More sharing options...
Ωhm Posted May 4, 2018 Share Posted May 4, 2018 6 minutes ago, gilman711 said: Is the Sync Sensor the one in the distributor? Yes Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 20 minutes ago, Ωhm said: Yes The Sync Sensor is currently plugged in. I have not tried to start with it unplugged to see if any change. Is C109 Sync Sensor connector? Greatly appreciate yours and everyone's help! I do have another complete distributor assembly I'm going to try as well. Link to comment Share on other sites More sharing options...
Ωhm Posted May 4, 2018 Share Posted May 4, 2018 C109 is a inline connector (engine harness to engine control harness) located on the right side of the engine bay. Sync Sensor is C231 and ground pin is "A" (harness side). Link to comment Share on other sites More sharing options...
Eagle Posted May 4, 2018 Share Posted May 4, 2018 5 hours ago, gilman711 said: Pictures show it at TDC and where the Rotor is in relation to #1 cylinder which appears to be lined right up with it. According to the Cruiser54 regarding Cam Sensor: "For clarification though, that’s not a cam sensor inside the Renix dizzy. It’s there to fire the injectors sequentially with the firing order. You’ll never notice if it went bad because the ECU will try to “guess” where it is and does a heck of a job at it. " But is it TDC on the compression stroke? Link to comment Share on other sites More sharing options...
HOrnbrod Posted May 4, 2018 Share Posted May 4, 2018 2 hours ago, gilman711 said: I held my finger on cyl 1 when rotating engine to verify it was on compression stroke. Just now, Eagle said: But is it TDC on the compression stroke? Looks like he has the timing marks aligned at TDC. Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 Replaced complete Distributor with a good known working unit and still no dice. I even tried starting with Sync Sensor unplugged and no difference. I have not lost hope but this Jeep really has me at a loss... I am updating original post too as far as parts replaced and things tested. Original issue still present of getting spark/fuel/air and no start condition. What am I missing here? Link to comment Share on other sites More sharing options...
Jeep Driver Posted May 4, 2018 Share Posted May 4, 2018 Was this engine replaced? Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 Mystery plug is coming from main harness as well as a small single wire (solid black) on passenger side. Mystery Plug Wiring A- BLACK WITH YELLOW STRIPE B- BLACK WITH WHITE STRIPE C- BLACK WITH BLUE STRIPE D- PINK WITH BLACK STRIPE Link to comment Share on other sites More sharing options...
gilman711 Posted May 4, 2018 Author Share Posted May 4, 2018 3 minutes ago, Jeep Driver said: Was this engine replaced? Yes it was but not by me. I have receipts for motor but doesn't say much information as far as what year/vehicle it was actually pulled from. Link to comment Share on other sites More sharing options...
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