Progress Thread 2.3L - crank no start issue. Has spark, fuel, good compression.

[joystang]

Hi first time posting. I have a confusing headache of a problem that I can't figure out. I have a n/a 2.3 engine and a4ld trans from what I believe was a 1993 mustang in a Joyner frame. It cranks but won't start, fuel injectors aren't getting a pulse. Here are the details:

Spark: tests good, bright spark using basic spark plug tester

Compression: 1-182, 2-184, 3-184, 4-182

Fuel injectors: 14.4 ohm readings for all 4

Timing marks line up with timing cover marks

Noid test: nothing during crank until key is released then light will blink one time.

Ecm: tried swapping with a good one, no change

Pip from crankshaft: not sure what it's supposed to be reading but voltage changes as engine is cranked by hand. 0.00 ohm reading wire has continuity.

Pip into icrm: same as above

Pip out of icrm: same as above

Constant 12v at fuel injectors until cranking starts then voltage drops

I have a wire going from the bottom left screw on the icrm to the neg battery terminal

Tps: tests a little high when closed 1.1 but goes to 4.16 wot

Grounds are all good

Pulled codes, most related to emissions system (don't have) and power steering (need to fix/delete). But I have a 522 which is vehicle is not in park during koeo self test. Would this keep the car from starting?

Tested park neutral switch, seems to be working fine. Tried bypassing, still get code.

Any ideas what's going on? Thanks in advance for any help, I've been going in circles trying to get this thing running again for a while.

 

[General karthief]

Pics of this buggy please.
Will the noid light flash with key on and jumping the solenoid?

 

[joystang]

Pics of this buggy please.
Will the noid light flash with key on and jumping the solenoid?

I'll put some up later.

Noid light only flashes one time upon release of the key when cranking. Bypassing the solenoid does not change anything.

 

[General karthief]

Check the ignition switch under the dash (not the key switch), I think there is a relay next to the computer that may be the issue also.

 

[joystang]

Ignition switch got replaced but I'll check it again. Computer relay is good, have tested it on other circuits

 

[Noobz347]

Tps: tests a little high when closed 1.1 but goes to 4.16 wot

1.1 and 4.16 what?

 

[joystang]

Volts

 

[Noobz347]

If your TPS is like the one on 5ohs, that's way out of range.

Hopefully one of these other dudes will know. Can you make out a part number on yours?

 

[Noobz347]

I'm going to move this over to the [General] section just to get some more eyes on it (with a redirect link).

Oh, and a slight modification to your thread title.

 

[joystang]

I do not know the tps part number off hand I will have to check.

Thanks, I appreciate the help!

 

[General karthief]

Actually the 1.1 v tps reading is at the high end of the spectrum, I think you may have a fuse link issue or ground issue, this buggy have a ground from the engine to body? Unless the body is fiberglass or composite of course, then the engine should have a ground to the same metal the instrument wiring grounded to, also check the ground wire in the injector harness, on V8 cars I believe it's orange and is in the injector harness, bolts to intake or back of head.
there should be fuse links at or near the starter. Check those.

 

[Noobz347]

Actually the 1.1 v tps reading is at the high end of the spectrum, I think you may have a fuse link issue or ground issue, this buggy have a ground from the engine to body? Unless the body is fiberglass or composite of course, then the engine should have a ground to the same metal the instrument wiring grounded to, also check the ground wire in the injector harness, on V8 cars I believe it's orange and is in the injector harness, bolts to intake or back of head.
there should be fuse links at or near the starter. Check those.

Yeah, but 1.1V is his [low] side. At 4.6V that thing is almost completely shorted (if it's like the 5oh TPS).

I just don't know what reference voltages are supposed to be for the 2.3L.

 

[joystang]

Actually the 1.1 v tps reading is at the high end of the spectrum, I think you may have a fuse link issue or ground issue, this buggy have a ground from the engine to body? Unless the body is fiberglass or composite of course, then the engine should have a ground to the same metal the instrument wiring grounded to, also check the ground wire in the injector harness, on V8 cars I believe it's orange and is in the injector harness, bolts to intake or back of head.
there should be fuse links at or near the starter. Check those.

Couldn't have a fuse link issue, doesn't have any. Previous owner removed them all, I have replaced them with regular fuses for the time being (I know they're not the same). I thought it might be a ground issue as well so I grounded everything to the - battery terminal, still doesn't start. All stock grounds have either been replaced or added if not there. I have the 2.3, the ground wire goes to the pcm and is internally grounded. I've cracked the pcm open and looked for any kind of damage, did not find any.

Yeah, but 1.1V is his [low] side. At 4.6V that thing is almost completely shorted (if it's like the 5oh TPS).

I just don't know what reference voltages are supposed to be for the 2.3L.

Only number on the tps when I took it off is 0057H15.
Not sure what the signal is supposed to be either, unfortunately there isn't a whole lot of non "make my pony faster" information on the internet for 2.3's

 

[Noobz347]

Yeah... The 2.3s were not nearly as prolific as the 5ohs.

I suspect though, that they use the same TPS sensor. If so, it should scale from 0 volts to around 1.0 volts at WOT. Anything above 1.0 volts would be disregarded.

Never had a 2.3L so I can't say any of that with any confidence.

 

[joystang]

Yeah... The 2.3s were not nearly as prolific as the 5ohs.

I suspect though, that they use the same TPS sensor. If so, it should scale from 0 volts to around 1.0 volts at WOT. Anything above 1.0 volts would be disregarded.

Never had a 2.3L so I can't say any of that with any confidence.

Alright, I'll try swapping it out for a new one. Any reliable manufacturer recommendations or ones I should avoid? Lol

 

[AeroCoupe]

Would like to offer my take on TPS voltages. My understanding is that all EEC-IV's use the voltage of the TPS as follows:

Closed Throttle - between 0.6 to 1.1 volts
Part Throttle - starts at 0.04 volts above closed throttle
Full Throttle - starts at 2.71 volts above closed throttle

When the ignition is turned on the EEC "sees" the TPS voltage and sets that as the closed throttle voltage. From there it goes to part throttle and up to full throttle. The maximum voltage the EEC "sees" is 4.9 volts.

So back to the max closed throttle voltage and maximum voltage the EEC "sees". You do not want to set the voltage any higher than 1.0 volt on the closed throttle position due to not all sensors are created the same i.e. accuracy. For example, if you set the TPS closed voltage to 1.1 volts and the TPS itself vaires 2-3% it will now be out of range. With that said I would keep the TPS closed throttle value between 0.7 volts and 1.0 volts to account for old wires and sensor issues. I know that the VREF with the EEC-IV is supposed to be 5.0 volts but I am pretty sure the engineers limit the maximum that the EEC "sees" to 4.9 volts for tolerances in sensors, wire, and the EEC itself.

Anyhow, just some food for thought.

 

[Noobz347]

With that said and still running the assumption that yours is the same as on the V8, I would look this over:

Mustang TPS Adjustment - 0.999999v not necessary

EDIT: This post applies to 86-93 5.0 Mustangs. Seems to be a common myth, so lets sticky a thread explaining how the TPS works. Jrichker has provided the basic TPS guideline to follow. But here's a snip of the A9L GUFB which is the programming logic. Pay attention to the part highlighted...

stangnet.com

 

[joystang]

Thanks guys! I saw that post on the tps adjustment, I just wasn't sure if that applied to the 2.3's as well. Going to try swapping it for a different one to see if that makes a difference. It'll be a little while though, don't get paid till next Friday

 

[Noobz347]

Rog... Let us know what you find out along the way.


Curious minds want to know

 

[General karthief]

I'm not convinced it's the tps.
But I'm not a real mechanic, I just play one in the back yard.