Need help with engine troubleshooting

[rekles]

Ive had this truck project going on for a year or so now and i am finally starting to get it where it almost 100% done and i can drive it again.

I started with a 99 4.0 ohv xlt 2wd automatic. I blew the heads on it so it sat for a while.

I came across a 2002 4x4 automatic 4.0 sohc xlt that had been rolled but the engine had low miles on it and ran great.

I eventually pulled the sohc engine out and put new timing chain kit with gaskets and cleaned out the engine as best as i could without pulling the heads off. Got a newer 2wd transmission to work with the sohc engine then dropped it into the 99.

I also found tan interior for super cheap out of a 03 i believe so i swapped over the dash too.

i finally got everything but the vacuum lines hooked up and it would not start.

Used a little starting fluid and it fired up for a few seconds, figured out the inertia switch was not hooked up so i spliced those wires together and it fired up for a second then died.

I came back the next day to mess with it again but no dice . it smells like it is getting fuel and ive been using starting fluid but it wont start at all. i checked the spark by hooking up a spark plug test light and everything looked good.

so far i have new belt, plugs,fuel filter air filter, and battery.

what should i check and what should i look for?

also no cel and i am using a different Gage cluster than what came from the 2002 doner


As always thanks for any and all help

 

[RonD]

The PATS(passive anti-theft system) disables fuel pump and fuel injectors but spark still works.
So engine would start if fuel was added manually, but wouldn't stay running, no injectors

The 1999 and 2002 PATS systems were different
1999 used a PATS module hooked to PCM(computer), above glove box
2002 had PATS in the PCM, so no external module

Both had a Theft light on the dash, it would come on then go off after a second with key on, if it Flashed Rapidly with Key on it means fuel system is OFF and the PATS key in the ignition is either the wrong one or could not be read.

First I would listen for the fuel pump with key on, it should run for two seconds, but two seconds only.
Repeat key on and off as much as needed to determine if fuel pump is coming on.
Its not quiet, you can hear it in the cab, a HUMMMM

If no HUMMM then most likey a PATS issue

The Transceiver is on the key switch, a round "wand" antenna using a 4 wire connector
In 2002 this was powered by a separate fuse, 1999 it was power by PATS module and its fuse.

Below is 2003 PATS wiring, same as 2001 and 2002

Its pretty straight forward, key on power and ground for transceiver and 2 wires to the PCM
BUT..........you do need the correct PATS key from the 2002 vehicle, because its number is in 2002 PCMs memory, not your 1999 PATS key number.

A mobile Locksmith can use a laptop to add your 1999 keys to the 2002 PCM

 

[rekles]

Thanks on the info on the pats but im pretty sure the pats is ok unless it has something to do with another cluster being in the truck. When i did the swap i swaped over all wire harnesses, lock and tumbler, ecm, and key from the doner 2002 truck.
I did have a few issues with the wiring of the door locks and windows and no chime when door left open with the key in the ignition.
The 99 had a few wires going from the drivers door to some sort module located right underneath the center of the rear window inside the truck. I think it was a pats module that the 98,99, and 2000 had only.

I think i hear the fuel pump com on and the anti theft light goes off after a few seconds.

im pretty sure it is a ignition or spark issue, maybe a relay issue?
just not sure what to check first

 

[RonD]

If Theft light comes on and goes off then yes, not a PATS issue

The starting by adding fuel manually suggested that it was.
Since engine starts and then dies from adding fuel manually(50/50 test), then spark is OK, trouble will be with fuel delivery, unless.......

Coil pack has an odd firing order
Image here: https://ww2-secure.justanswer.com/uploads/drivefast1971/2010-07-03_143331_2.gif

On one side, closest to connector, its 1 2 3, but other side is 5 6 4

So yours make look like this
1 2 3
5 6 4
front

or
3 4
2 6
1 5
front


So 1 is closest to connector on the end
1 and 5 are always matched, as is 2 and 6, and 3 and 4
Double check and then triple check



All the fuel injectors should get 12volts with key on, that's from the PCM relay in the engine fuse box.

The Coil(spark) gets 12volts from another fuse.

Each injector will have a Red wire, that's the 12v wire it just daisy chains from one injector to the next
Test one of the Red wires to make sure it has 12v with key on, on or off the injector, doesn't matter.

2002 Fuel rail may or may not have a test port, looks like a tires air valve because that is what it is, a schrader valve.
If you have one you can test if there is pressure at the fuel rail by pressing in center pin, same as a tires air valve, but be careful, 55psi pressure can squirt a long ways.

 

[rekles]

Thanks Ron i think the fire order is on point,gonna double check it in a bit. also wont start at all with starting fluid. checked all fuses and they are good tested 1 cylinder with a plug light tester and its good so i guess ill check them all and the firing order in a bit

here are some pics to humor you

 

[RonD]

If it won't start with starting fluid then spark is not working.

Computer starts spark when it detects AC Voltage pulse coming from the Crank Sensor.
Crank sensor generates its own AC voltage, about .5vAC when cranking, more after startup.
This times spark and injectors.

CAM sensor is also used but after startup, it fine tunes injector timing

 

[rekles]

Just swapped out the crank sensor and rechecked the spark plug wire orientation witch i had correctly. Engine fired up for a second then died. Sprayed starting fluid in it and would not fire up again.

What next?

 

[rekles]

Also another thing i just noticed is the check engine light is not coming on when the key is in the on Position

 

[RonD]

Fuse #11(7.5amp) in cab fuse box powers CEL with key on, in 1999 or 2002, Computer Grounds CEL bulb to turn it on when it boots up

Fuse #11 also powers a few dash instruments like Tach and Voltage gauge

The 1999 and 2002 dash wiring looks the same

Fuse #25(25amp) in cab fuse box powers the coil with key on, and also powers PCM relay which powers PCM via Fuse #7(2002), #8(1999), either is 30amp

There is also a PCM Power diode in engine fuse box

 

[rekles]

Checked all the fuses and they are all good

 

[RonD]

Are the gauges on the dash working and the other warning lights?

The fact the Theft Light comes on and then goes off means the PCM is booting up and running PATS test, I assume

But if PCM is then shutting down????

Do you have a OBD2 reader to see if PCM is on and communicating?

 

[rekles]

Swapped pcm diode and pcm relay, also added a few more 6 gauge grounds to the body and engine.

Also checked every coil connection to the plug wire with a cheap spark plug light tester. Everyone tested lit up bright.

Any clue what i should check next or ? Is there any way of testing the pcm? Or does it sound like the pcm could be faulty?


What next?

 

[rekles]

I do have a cheap code reader ill try to see if i can pull anything from it right now

 

[rekles]

All the other gauges seem to be working on the cluster like battery, oil pressure, gas, and rpm.

Im not sure how to tell if the code reader i have right now has that capability, i was able to see a live data of rpm's, engine load, fuel banks, air temp, coolant temp and a few other things. Ran a test and it said no issues found.

 

[rekles]

Any other suggestions?