novanut1964 Posted June 13, 2021 Share Posted June 13, 2021 1987 2.5, rebuilt engine. ran 2 days then started dieing while driving. sometimes start up, sometimes wait hours. new map sensor, tps sensor, 3rd new crank position sensor, new battery, new battery cables, new starter, clean grounds, add ground to fuel pump harness, new fuel pump today ran awhile, cut off. new fuel pump relay, clean relay socket, new ignition relay, ran better with old. new coil, new ignition control module, add ground cables block to frame. c101 already bypassed removed 2 crimp connectors-soldered. remove ecm look inside no burnt places, renix engine monitor helps watch, i have touched renix monitor connection engine died, touch tps connector, dies, touch map connector, dies, something different every time i troubleshoot the problem. touch key in column after fuel pump today engine died. wouldnt restart. everything new, any ideas? can't drive. videos search novanut1964 on youtube thanks Link to comment Share on other sites More sharing options...
novanut1964 Posted June 13, 2021 Author Share Posted June 13, 2021 also 2nd new O2 sensor, unsoldered throttle body lead plug, adjust fuel pressure to 15#, add fuel pressure gauge to tbi port, have new diapragm didnt install as was working, new air filter, new intake air temperature sensor-correct ohms, moved to before tbi hat. vacuum hoses routed best i could dechipher, new pcv valve. 2nd set mew spark plugs engine has less than 300 miles after machine shop rebuilt, retorque rocker arm nuts, some lifter noise, bought newelgin lifters and pushrods after it stays running. new turn signal cam switch in column. if remember anything else i have done i will post it. couldnt get rear tail light cover off to clean ground yet. inside ecm big plug some wires soldered i assume cps wires not sure yet, i ordered an rebuilt 1989 4.0 automatic ecm to try. ordered correct shank cps bolts, on the way. yesterday i grounded positive battery cable to negative 30 seconds started and ran longer than it has in a month. please help i want ti drive it. thanks Link to comment Share on other sites More sharing options...
novanut1964 Posted June 13, 2021 Author Share Posted June 13, 2021 also new fuel filter replaced. new water temp sensor. watched temperture rise on renix monitor to 190, sometimes 205 if idleing long to test. chd intake bolts, new gasket. Link to comment Share on other sites More sharing options...
novanut1964 Posted June 13, 2021 Author Share Posted June 13, 2021 unplugged all engine connectors, sprayed with electric cleaner Link to comment Share on other sites More sharing options...
jdog Posted June 13, 2021 Share Posted June 13, 2021 when it dies, check for spark and see if theres pressure on the pressure gauge. Welcome @eaglescout526 Link to comment Share on other sites More sharing options...
jdog Posted June 13, 2021 Share Posted June 13, 2021 @Ωhm Link to comment Share on other sites More sharing options...
eaglescout526 Posted June 13, 2021 Share Posted June 13, 2021 Yeah Ive been trying to figure out what his issue might be. Been reading what he has been posting and hes done a metric ton of crap to it to try to make it run. Link to comment Share on other sites More sharing options...
jdog Posted June 13, 2021 Share Posted June 13, 2021 all ive come out with is its a heat issue Hows your ignition switch(the one half way down the column? how are the fuse links? Link to comment Share on other sites More sharing options...
scaleless Posted June 13, 2021 Share Posted June 13, 2021 Does it immediately shut off, or does it lose power and sputter out? Does the issue happen while cruising or only at idle? Link to comment Share on other sites More sharing options...
Ωhm Posted June 14, 2021 Share Posted June 14, 2021 On 6/13/2021 at 3:44 PM, novanut1964 said: i ordered an rebuilt 1989 4.0 automatic ecm to try. Don't. You got a 2.5L. On 6/13/2021 at 3:44 PM, novanut1964 said: ordered correct shank cps bolts, on the way. We need to wait and see how these do. Watched your REM recording (youtube) made about a month ago. IDLE seems HIGH (≈1050rpms). Shows no CLOSED THROTTLE @ IDLE. Intake air temp (f°IA) also seems high @ around ≈245F°. ST shows ECU is adding fuel, but could be normal for HIGH IDLE. Link to comment Share on other sites More sharing options...
cruiser54 Posted June 14, 2021 Share Posted June 14, 2021 I would slow down on the Parts Cannon approach. A TCU certainly would not cause the condition you are describing. Have you completed Tip 5 at www.cruiser54.com? Sounds like a common ground to multiple sensors could be the culprit. And for sure, there is a good ground firewall to engine? Link to comment Share on other sites More sharing options...
novanut1964 Posted June 14, 2021 Author Share Posted June 14, 2021 new fusible links, iat sensor was reading high on video i got correct ohm sensor now. just ran extra ground cable from computer ground to negative battery, it ran longer than it has in months. cleaned ground behind taillight also clean/ replaced taillight bulbs. when headlights on right turnsignal indicator lights up a little. tried ohm from tps b ground not sure if reading right Link to comment Share on other sites More sharing options...
cruiser54 Posted June 14, 2021 Share Posted June 14, 2021 what are the readings at TPS ground to battery ground? Is the big cable attached to the engine and firewall? If so, the paint needs to be cleaned off the firewall and the oil off the engine where it attaches. Link to comment Share on other sites More sharing options...
novanut1964 Posted June 15, 2021 Author Share Posted June 15, 2021 ohms at tps b terminal starts at 18.5 drops to .5 maybe 10 seconds steady dropping. any help appreciated. Link to comment Share on other sites More sharing options...
novanut1964 Posted June 15, 2021 Author Share Posted June 15, 2021 braided cable to firewall cleaned Link to comment Share on other sites More sharing options...
cruiser54 Posted June 15, 2021 Share Posted June 15, 2021 Get an ohms reading on the black wire on the ignition control unit. Have you ever refreshed the ICU? Tip 2. Link to comment Share on other sites More sharing options...
cruiser54 Posted June 15, 2021 Share Posted June 15, 2021 Need to do Tip 1 also. Link to comment Share on other sites More sharing options...
novanut1964 Posted June 15, 2021 Author Share Posted June 15, 2021 23 minutes ago, novanut1964 said: braided cable to firewall cleaned . all grounds cleaned, 2 grounds added one from alternator bolt to radiator support, one from back intake bolt to battery, started up after i checked tps ground, i rapped on bottom of steering column comamche shut off will check igntion control in column tomorrow, about the only thing i havent replaced. Link to comment Share on other sites More sharing options...
cruiser54 Posted June 15, 2021 Share Posted June 15, 2021 Link to comment Share on other sites More sharing options...
novanut1964 Posted June 16, 2021 Author Share Posted June 16, 2021 took ignition switch apart, wasnt burnt, it was corroded, the copper slides had wear marks and some heat discoloration, waiting on mew rockauto seitch Link to comment Share on other sites More sharing options...
novanut1964 Posted June 16, 2021 Author Share Posted June 16, 2021 new switch Link to comment Share on other sites More sharing options...
novanut1964 Posted June 17, 2021 Author Share Posted June 17, 2021 recent pic before it quit running Link to comment Share on other sites More sharing options...
Jeep Driver Posted June 17, 2021 Share Posted June 17, 2021 46 minutes ago, novanut1964 said: recent pic before it quit running You've got the 2.5. You've added a fuel pressure gauge. Watch your gauge when turning the key to run. If you cannot see the gauge have a helper turn the key. Pump will run for 2-3 seconds then shut off if starter is not engaged. You should see pressure build then reduce to 0 again. Cycle a couple to times to insure that pump will prime in the run position. When the starter is engaged- If ECU does not see signal from CPS you will get no fuel pressure....pump will remain off. This will tell you one of three things are happening- Pump failure. CPS failure. Coil failure or I suppose could be ignition module failure. IOWs, it's my experience that any ignition failure will result in ECU keeping pump in the off no-run condition. Unfortunately most aftermarket products are junk out of the box. OEM only if you can find it. Link to comment Share on other sites More sharing options...
novanut1964 Posted June 17, 2021 Author Share Posted June 17, 2021 thanks, picking up new ignition switch for steering column tomorow, just replaced fuel pump ran smoother. on 3rd new cps, last one is a Siemens, coil and ignition module are new, within 2 weeks ago. i will update after new part installed. i appreciate any help. alot of time and $, can't drive its too unreliable so far. c101 already bypassed i resoldered the brown ground wires Link to comment Share on other sites More sharing options...
novanut1964 Posted June 25, 2021 Author Share Posted June 25, 2021 replaced ignition column switch. still cuts off. took computer out again, new 1989 computer pins different. reinstall still cuts off after 20 minutes or so of running. unreliable can't drive. any more advice? only connector i havent cleaned is under brake master cylinder. hard to get at. Link to comment Share on other sites More sharing options...
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