I'm thinking the main difference between the 19186079 and the 16147525 is obviously the hexadecimal address in the chip and the associated electronics inside the computers.
For example,
1987 ~ 1991 TBI computer 1227747 uses definition $42 vs. the 1992 TBI computer 16146299 uses definition $99; both use the same 4K chip. The programming hexadecimal code is very different $42 vs. $99 and likely different electronics for things like the Injector Drivers, IAC, TPS, Knock Sensor, and others.
It would be a VERT BAD Thing if somehow a 1227747 computer chip was installed into a 16146299 computer and vise - versa.
Basically installing a 16147525 chip into a 19186079 would be considered a VERY BAD Thing too.
i see what you mean, i lucked up and finally found the proper ECM from a heavy duty salvage yard up north (im down in the bible belt) and they are gonna ship it in the morning.
until then i am going to focus on the other issues and report back ASAP.
GOOD NEWS!!!
The ECM i ordered from Active Truck Parts came in today, and that fixed the problem! Apparently there is a certain type of ECM for these big trucks '91 and newer..
I sent my Driver side Fuel tank off to a local body shop to be cleaned and relined inside while i have the truck down (slight rust inside), so i should have it back next week hopefully.
Very big thanks to Dave W and Steveo for their inputs, comments, and suggestions!
I sincerely hope that anyone with an issue like or close to mine can benefit from this thread!
Basic information to help with diagnosis:
The ignition module will fire the coil without a working ECM. Checking for spark while cranking only tells you the coil and pickup coil is working and that the ignition module is partly working.
The ignition module will send a pulse to the ECM for each spark made at the coil.
The ECM will use pulses from the coil to fire fuel injectors.
If you install a noid light at the injector and spark tester on the coil wire you should see noid light blink when spark tester sparks. The "netres" or backup fuel hardware will make this happen even if the calibration in the eprom is bad.
Sorry for the delayed response guys... been very busy with work.
so after cleaning the fuel system and having the tank re-lined i now have fuel to the injectors, and i also have spark as well.
The engine will try to start, but instantly stalls. It will try to stay running if i pump the throttle, but it acts like (in my personal opinion) it is not getting enough fuel.
I jumped the starter solenoid to watch the injectors and they have a constant spray.
I have replaced the IAC valve, Coolant temp sensor, TPS, and MAP sensor before the truck started giving me issues. So i have not reason to believe that any of that is the cause.
No codes are being thrown, and i cannot get any useful data from the live reading from my laptop.
I am going to ask / throw a curve ball idea or question.
I remember in the late 80's and early 90's, EFI used the Oil pressure sending unit as a fuel pump shut off. When to truck was started the oil pressure sensor was bypassed for x amount of time. Then when started the oil pressure would tell the computer to keep the power to the fuel pump on.
So I am wondering if, the truck starting and then stalling could be an issue with oil pressure sensor and or wiring.
If the Kodiak, ran this style fuel pump control set up.
Do you have the correct fuel pressure and volume? Is the ignition timing set properly?
So i finally found the last piece of this nightmare... as stated above i didnt have either of the correct fuel pressure or volume. APPARENTLY O'reillys sold me the fuel pump for the
passenger side instead of the driver side... the right pump is out of stock through them, but autozone actually had the right pump. I slapped it in there and BAM she started up just fine! After a little fidgeting with the timing she runs like a top!
The part number for the pump O'reillys sales is "E16031" that is for the passenger tank and the output is apparently 3PSI and 15GPH..
The correct pump is a Delphi "CFE0112" rated at 30-40 PSI and 36GPH.
Boy has this surely been a ride, but i hope my mistakes, both costly and frustrating will be of great help to others in the future!
-Cookie70
Interesting, looks like the passenger pump is used to transfer fuel to the driver's side tank? I couldn't find any info for fuel or ignition specs for this. Glad you figured it out.
I haven't looked at this thread in a bit but I'm glad you've found a solution. I never thought about getting the wrong pump. The low pressure pump is definitely not going to be enough to run the engine.
That dual tank system is a mess. There's a fuel level module that monitors fuel level in the primary and secondary tanks. The primary tank supplies fuel to the engine. When the primary tank fuel level gets low the module turns on the low pressure transfer pump and moves fuel from the secondary tank to the primary tank. If both tanks are filled at the beginning of a trip this transfer will happen three or four times before the secondary tank is empty.
The mess is that GM connected a single fuel gauge to both primary and secondary fuel tanks in parallel. This configuration makes it so the fuel level is only accurate at full or empty. In between you have some combination of sender readings that may or may not closely represent the total amount of fuel. Worse still, if you fill the secondary tank but not the primary tank, the smaller volume of the secondary tank causes the gauge to read closer to full. A second gauge or a switch to allow one to view fuel level independently would have worked better imo.
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