88MJBahamasBound Posted January 5 Share Posted January 5 1988 Comanche 4x4 5 speed 190k. "Rust free" colorado truck. Rebuilt the head over the summer. Just got it put back together after extensive work, including: -dropped fuel tank and painted it, did not replace fuel pump but replaced screen, tank seal, fuel hoses -pulled the connector off the fuse block from the engine side of the firewall, removed the 2 large phillips screws holding the fuse block in. Visually inspected, cleaned some tar from the connector and put it back together -flipped the vacuum motor for the 4x4 engage on the front axle after reassembly the motor runs like crap unless the throttle is at least half way open...rough idle, rich gray smoke, sputters at lower rpms. I cannot find a vac leak....everything looks fine including the red vac line to the 4x4. Vacuum can is holding vacuum. Checked the fuel pressure and it looks right in the 30ish psi range. Added some sea foam 30 miles ago and mayyyybe it's doing better? Have a new fuel filter but haven't installed yet So my guess is either there's a stuck injector or (much more likely) I messed up something either in the fuse block or disconnected something under the steering wheel (besides the emissions timer (do i need the timer??)). I definitely DID snap off the wire going from the blower fuse to the hvac control (wiring is "rust free"). Sooo guess it's time to get some fuse terminal crimps but i really need to get on the road. I'm going to inspect the wires tomorrow, clean the tar from the connector with brake fluid, reassemble and pray. After that, order the crimps, bus crimps, special crimper, and a renix engine monitor (which are on back order i think). ANY ideas, suggestions, or just hindsight critiques are welcomed. In my own defense, the fuses are loose which already lead to one breakdown on the highway (as well as a long walk to a motel and a lot of head scratching til i finally dug into the wiring diagram a year later). THANKS Link to comment Share on other sites More sharing options...
jdog Posted January 5 Share Posted January 5 Did it run after the head was installed? It is either the map sensor vacuum line or a vacuum leak at the intake then if the answer is no. https://cruiser54.com/?p=280 That throttle body has two holes for the map sensor, the vacuum lime goes in the bottom one. Why are you using brake fluid to clean the connectors? Should be using electrical cleaner. Brake fluid will eat the plastic and ruin connections. No you don't need that timer. Link to comment Share on other sites More sharing options...
88MJBahamasBound Posted January 5 Author Share Posted January 5 Thanks for the reply. Yes engine ran pretty darn good for 6 months after the rebuild. I redid the vacuum lines when i rebuilt it but i'll check them again. I do have contact cleaner, but i saw a writeup on Renix engine's having a "black tar like substance" in their C101 connector: https://cruiser54.com I see the same tar in the fuse block connector. I can try the contact cleaner first though. Link to comment Share on other sites More sharing options...
Ωhm Posted January 5 Share Posted January 5 11 hours ago, 88MJBahamasBound said: after reassembly the motor runs like crap unless the throttle is at least half way open...rough idle, rich gray smoke, sputters at lower rpms. If battery cables were disconnected, ECU will need to relearn itself, but your symptoms seem quite extreme for relearn. With each restart is there any improvement? Link to comment Share on other sites More sharing options...
jdog Posted January 5 Share Posted January 5 Then the next thing I would do is a fuel pressure test, possible that the hose came off the fuel pump or has collapsed Link to comment Share on other sites More sharing options...
88MJBahamasBound Posted January 5 Author Share Posted January 5 I did test fuel pressure. mentioned it in the first post. looked close enough to 31 psi through all rpms Link to comment Share on other sites More sharing options...
jdog Posted January 5 Share Posted January 5 With our with out the regulator plugged in Link to comment Share on other sites More sharing options...
88MJBahamasBound Posted January 5 Author Share Posted January 5 regulator was plugged in. haven driven several hundred miles since putting it back together so don't think it's an ECU learning. Link to comment Share on other sites More sharing options...
88MJBahamasBound Posted January 5 Author Share Posted January 5 sorry bad link https://cruiser54.com section 2 is for the C101 terminal Link to comment Share on other sites More sharing options...
jdog Posted January 5 Share Posted January 5 Brake cleaner is fine, brake fluid is not, what does the pressure do with the regulator unplugged Link to comment Share on other sites More sharing options...
88MJBahamasBound Posted January 6 Author Share Posted January 6 typo, meant to say brake clean. will check fuel pressure without the reg tomorrow. Link to comment Share on other sites More sharing options...
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