eaglescout526

That's probably right, I just wonder why the couldn't label it more precise than just G110. But yes you have the ground post to engine block by alt bracket, then from bolt head to strap and then the dipstick ground, you also have that one on the drivers side fender but that does the blower motor, wiper motor and etc.

T8 goes to D2_6 to WOT then to splice D which grounds out at G110. Where ever that ground is at. 88 replaces the WOT switch for the PS pressure switch.

Hang on, uploading Pt II of the engine and fuel controls diagram that has the WOT, ISA and a few others.

Ok so the switch itself is good, low resistance at WOT and it should be infinite but I believe O.L. is the same, I think. Volt meters get weird around there. It passes the closed throttle voltage test but fails the WOT meaning there's something wrong with the harness which leads to testing for an open circuit in the wire or connector between the switch and ground.

Correct. To test the WOT you need to unplug it from the harness. Test the on off operation using a DVOM Digital volt ohmmeter Operate the switch The resistance should be infinite when the throttle is closed. A low resistance should be indicated when at the WOT position Test the switch several times Replace if defective(I don't even know if that switch is available) Reconnect it to the harness With the ign on test the WOT switch voltage at D2_6 to ground/D2_7 There should be no voltage reading at WOT position: greater than 2 volts if not at the WOT position If no voltage is present in either position, test for a short to ground in the wire harness or switch Check for open circuit between T8 of the ECU and the switch connector Repair or replace harness if necessary If the voltage is always greater than 2 volts, test for an open circuit in the wire of connector between the switch and ground.

Ok. Theres not a ballast resistor anywhere is there? And we have confirmed the pump runs for both one second and while cranking with jumped and relay?(just double checking) Do you have a Wide Open Throttle switch?(located on the throttle body by the bonnet and linkage) Book says to check MAP sensor but we can't even get 5V to it.

Yup that's factory.

If the MAP went bad it would struggle to accelerate right and idle either high or low. I wouldn't replace the TPS until the proper voltage gets delivered to both sensors. Like I said, they aren't getting the 5V and the sensors need the 5V to "run" themselves to send data to the ECU. I don't think throwing new sensors will solve the issue. Just for giggles, how do the spark plugs look?

I mean honestly the only person in the world I know who has the MS1700 is nickintime and I happen to have an ECU tester and so do 30 people on eBay. But the only absolutely last thing is the ECU and wiring harness.

That’s why we never did the adjustment because of the MAP sensor 5V. Something is bizarre so I am not certain if a new ECU will rectify the 5V problem.

Is it a Jeep forum? The adjustment is this: Key on engine off Check sensor input voltage, Connect negative lead to TB and positive to TC Note here is to not unfasten the sensor nor unplug it from the harness but back probe the connector. Move the throttle plate to wide open, be sure throttle linkage contacts the stop Note the reading for the input voltage for B and C should be 5V wide open Return throttle plate to resting. Check sensor output voltage by taking positive lead from TC and put it in TA. Move and hold the throttle plate wide open like testing the input voltage. Note this entire adjustment is with the throttle plate wide open so it will be a bit tough to do alone but it gets easier the more times it is done. Voltmeter reading should be 4.6-4.7VDC, adjust the output as necessary. Loosen the bottom retaining screw for coarse adjustment and loosen the top screw for fine adjustment until the output has hit between 4.6-4.7VDC and then tighten the screws while holding the sensor still during tightening.

We tried the tests for them and came up with bizarre results. We never got the 5V to the sensors from the ECU so theres something wrong somewhere and it all just might boil down to the 5V circuit.

Not that I can think of. Starter relay/solenoid is good as the engine cranks, ECU pulses the injector, injector is good on the resistance, spark comes from the coil, CPS tests alright, FP runs with good pressure, good bat voltage, fusible link to pin 30 for FP relay is good, ignition switch is good, engine fires with fuel down the TB. The only thing we absolutely don't know about is the MAP and the TPS.

No idea. Just sent him a PM talking about it, he's pretty good about getting back to me. At the moment he isn't sending the parts out yet but I can't make a promise on how quickly he can get the ECU out

Well theres a $100 you don't have to spend. I don't think those injectors ever go bad but they are just GM injectors.

Well, trying to help prevent ya from buying a new ECU. Not sure what the return policy is at parts stores on if the ECU fixes your problem or not. Buuuuuttt if we go the ECU route send @70barracuda a PM about a 2.5L ECU. I am buying his old one off of him and he could probably send the ECU to you for testing purposes.

Try anywhere inside the cab that touches the sheet metal. Also doing the resistance test on the injector should say something. Since you had the injector unplugged for the light test, take one lead and put one on one injector post and the other on the other post and see if it has more or less than 10 ohms resistance. Ok I missed this new page, disregard what I said.

WTF! Its like everything checks out. So I wonder what voltage is getting to T6(if any goes there) at the ECU connector, perhaps a voltage signal is not going to the relay to energize it.

No you can get a stalk without cruise with intermittent wipers. Only the cruise talk has a wire that leads down. But if its got pre H.O. cruise stuff I'm interested in it.

All I needed was something to go off of. Thanks. So with the relay installed do you see pressure on the fuel rail?

Hooooo, shes free of the tarp!

So both are getting power to them? So then it should be energizing the relay for the fuel pump.

Both of ya but mostly you. But lets do see what our voltage looks like where Ohm said.

Ok that eliminates the fusible link being blown. Could pin 86 be tested on the FP relay during crank to see if the ignition switch is sending voltage to energize the relay? Thanks Ohm!

Ok pressure is good, pump is good. That takes care of the fuel system as far as delivering fuel. What is the number for that pressure gauge kit so I can hunt one dow if you don't mind me asking? Your guess is as good as mine for the fusible links. Its all in that electrical diagram I posted in thirds. I would imagine the splices would be soldered pieces of wire in the harness. T16 on the ECU is the 5V supply for TPS and MAP. D1 D2 4 1 3 6 9 12 15 5 2 2 5 8 11 14 6 3 1 4 7 10 13 Which pins are you jumping on the FP relay? 30 to 87? That will rule out the fusible link for that area if you are jumping those two. Were just looking for voltage of some kind, not resistance.