wrangler8987 Posted February 28, 2015 Share Posted February 28, 2015 I have a 89 wrangler 2.5L I just replaced the fuel pump thinking it was bad put the new in same problem wouldn't kick on hooked it the battery kicked on tryed to crank it nothing pull inlet off the throttle body getting fuel there but not coming out the injector touched injectors to battery it's worked any ideas what could be cause this any help will be helpful bcause I don't know much about TBI. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted March 1, 2015 Administrators Share Posted March 1, 2015 Hi, Wrangler8987...Since devices work when directly tied to the battery, I would suspect an ECU issue. However, I'm not a buff of replacing parts unless necessary. My first troubleshooting would be the grounds. This 12VDC system is notorious for poor grounding from corrosion. Clean up the grounds and the battery, then the body-to-frame-to engine grounds. A prime trouble spot is the body ground to engine. The ECU requires body to frame grounding. Try grounds before investing in an ECU or other parts. Otherwise, there is either a module (ECU) issue or a wiring problem. Or a dirty (possibly defective) crankshaft position sensor. This is a common problem with the 2.5L TBI and other Jeep engines. Try cleaning and testing the CPS. Both the pump activation and injector pulsing are issues that require a crankshaft position sensor (CPS) and ECU signal, and the ECU could be involved. Rebuilt ECUs are not that expensive, though again, I would start first with ground and CPS possibilities. Read the threads/posts on the YJ TBI 2.5L here at the YJ/TJ Wrangler section. We've had lengthy posts about troubleshooting issues like you are currently experiencing. This includes discussion of grounds, the CPS, the ECU and other trouble spots... Moses Quote Link to comment Share on other sites More sharing options...
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