mattsmopars

First off Hello to all, as this is my first post here. I found the site while doing a search on the problem that I am having with my truck.
I bought an 89 4x4 truck with a blown 22re engine. It came with another 22re from a 1990 4x4 truck. I installed the replacement engine complete with the harness from the 90 model truck and had no problems until I got to the 2 plugs behind the computer in the RH kick panel.
The harness from the 90 model truck had a differnet clear colored connector and had 10 wires, instead of the 9 wire plug that was on my old engine harness.
All of the wires were the same color and position on both plugs except that the 10 wire plug has 2 black with red tracer wires, and the 9 wire plug just had one blk/ red tracer wire. So I took a pick and pulled the wires from the 10 wire plug and installed them in the 9 wire original to the truck plug and plugged everything up. I have one blk/red tracer that is not plugged into anything.
So when everything was installed and hooked up I started the motor and it will now run for a few seconds and die out. Will refire and do the same thing again.
I thought it was from lack of the fuel pump running, so i checked that it has 36 psi while it is running on the out side of the fuel filter. Over 40 psi if you jump it over inside the diag. terminal. I also checked the 1st injector with a noid light to see if it is firing, and it is as well.
So this leads me here to see if anyone might could help me out as I am not for sure what to do from here. I also tried the computer from the 90 model truck , but no difference. I also switched the blk/red tracer wires with no change. Any help would be appreciated and thanks for the site!
Matt

Bassmastry101

iTrader: (1)

Hows the AFM look? Is there a connection to it? There is a link to the FSM in my sig that will show you how to test it.

mattsmopars

I have not tested the air flow meter , but the fuel pump does turn on once the engine fires. Also the fuel pressure stays 36 psi till the engine stops running. I also unplugged the afm and crossed out the pump in the diag. port at the +B and the Fp so that the pump would run with the key on. It made not difference the engine starts up and runs a few seconds then dies.
Matt

XtraSlow_XtraCab

This sounds stupid, but is your air intake plumbing between AFM and TB ok with NO rips? Symptoms of this heavily reflect a vacuum leak, but is in fact quite the opposite.

Also, is the Circuit Opening relay plugged in with a known working condition? I'm relatively new to the EFI systems (just converted from carb approx. 6 mos ago) biut if I recall correctly THAT particular relay involves startup or fuel pump operation or something to that effect.

Download a vacuum line diagram from the FSM and look for vacuum leaks.

skypilot

iTrader: (1)

I do not think 1989 & 1990 wiring harnesses are compatible. I have a 1988 & 1990 & they are alien to each other.

You need to use the engine harness & electronics that are compatible to the truck. If the body harness is 1989 then you must use all the 1989 electrical components or you are barking up the tree for trouble.

I have a 1991 engine in a 1988 and it runs but I have the starter & Cold Start Injector hard wired to manual controls so it starts & runs. I have the ECU hot wired into the chassis since 1991 uses three hot wires to the ECU and the 1988 only has one.

I bet you are missing two of the +B signals to the ECU possibly all three.

I strongly suggest you put the 1989 hardware onto the 1990 engine, and I think you will save a lot of time & aggrevation. From your post it sounds like you have those pieces, nothing to buy.

mattsmopars

Well just to give everyone an update. I replaced the 90 model 22RE engine harness with my original 89 engine harness.
The 90 model engine had 3 sensors on top of the valve cover with vacumm lines to them, and my original engine only had two a red and a blue, so I used the original ones back.
I also replaced the complete throttle body with TPS, and the cold start injector all from my original engine. Got another upper air box with AFM and the plastic tubing from the truck that the replacement engine came out of and tried that as well. Also tried the other trucks coil and ignitior.
Basically no change it will run 7-10 seconds good and then die out.
I am sort of at a loss now as I have tried everything that i know. Thanks for all of the suggestions.
Matt

thook

Just to add to the confusion.........


You said in the beginning there were 10 wires from the '90 harness while there were only 9 terminals on your '89 ECU. You are talking about the ECU harness, correct? If it were me, dude, I would have just popped the '90 ECU in a that point and saved some time. Sorry to throw in the contradiction to an above post, but it sounds like, to me, your '90 engine is only different from the '89 truck in that some emissions equipment were added....specifically one extra "sensor" (as you call it...they're actually vacuum switching valves) on the valve cover that is, in fact, ECU operated. Unless, of course, the oxygen sensors from the '89 and '90 were different.....ie, the latter being heated while the former not.... or the '90 had a post CAT sensor...... and/or the '90 engine came from a vehicle with an ECT auto transmission (did it?). IIRC, the '89 model did/does have a heated O2, though. Whether or not the '90 would have a secondary O2, I'm not sure of. That may only be CA models. I'm thinking that's the case until Toyota went to OBD II in later years.

Another thing, trying to run the engine with the AFM disconnected even though you have the FP/B+ terminals shorted (in order to test the FP operation) will not work. You have to have the AFM connected regardless. Otherwise the FP can run all day long and the engine will still not run. The AFM controls more than the FP once the engine is running. It's a major piece of equipment.

Those vacuum switching valves on the valve cover.......one will be for the fuel pressure regulator (fuel pressure up....FPU/VSV) to maximize pressure in the rail under certain conditions, one will be for the A/C idle up system to raise the idle when A/C in operation, the last (from the '90 model) will be for the PAIR system so that is opens and shuts under appropriate load conditions. Note, none of these imperative to your engine actually running. In fact, were your engine running, you could disable all of them and it would still run......just not as optimally under associated conditions. For example, your engine may lag at idle with the A/C on, or the engine may have a tad bit of trouble starting smoothly after sitting hot for a period, the engine may run a tad lean under heavy load, or the PAIR system won't open/close when it needs to impairing emissions levels. But, the engine will certainly still run and not die on you like you're seeing.

Note, a good indicator for compatibility from year to year is whether or not connectors will mate up to any given component.....ie, TPS, ECT sensor, injectors, O2, AFM, ignition components, emissions sensors and valves, etc. If the connectors and components will mate up, then there's no compatibility issue. Sure....things like injector voltage can be a problem, but there was only one year in which that changed. It did not from the '89 to '90, though. The change was made, IIRC, at '89 being the same up to '95.....called "type F" injectors. '88 and before were all the same.....which would be one reason the above poster ran into issues.

Anyway, do what you want, but if I were you, I'd go back to using all the '90 harness and ECU if I knew the '90 engine and system were operative before it was removed from the donor vehicle. Reason being, if you have to pass emissions, that PAIR VSV needs a wire to the ECU to work and will affect whether or not you pass. If it's not an issue, then just disable the PAIR system and keep all your '89 equipment that you've already swapped in. However, you may get a CEL. Up to you.

As for actually trouble shooting your problem, here's the '92 FSM troubleshooting guide (yes, it does apply to you though the year is different):

http://personal.utulsa.edu/~nathan-b.../3troubles.pdf

Read the line of troubleshooting components according to your symptom..."stalls soon after starting". Note, the first troubleshooting tips are for the fuel system. You said your pressure was 36psi at one point and then over 40psi with the FP/B+ terminals shorted. That all sounds good and close enough within range, but it doesn't tell you if the FP is actually dropping out causing the stall. You need to test the FP (not necessarily the pressure) once again with the AFM connected and engine running. That is, see if the engine will continue to run. If not, move to troubleshooting the other given areas in order of numerical importance.

mattsmopars

The 10 wire plug was not to the ECU all 3 of those connections were the same and pluged right in. It was the clear colored plug of the two plugs you have in the RH kick panel when you pull the ECU down. I did also try the 90 ECU before I changed back to my original engine harness, and sensors. As you say I think one of the vacuum swithes that the 90 model had was for A/C and my truck does not have A/C on it. All of the other connections were the same at every sensor including the O2, and the 90 model truck was also a 5 speed 4x4 as well. As for the AFM I do need to test it by the chart, but when I jumped the +b and the Fp I had tried it unplugged and plugged in both to see if it made any difference, and it did not. I also tried the 90 model air box with AFM and it was the same , and that is not to say that they both could be bad. I will check out your troubleshooting link and check the AFM with a multimeter later in the week. Thanks, matt

thook

Oh, that plug....right. I was thinking since you were swapping out the '90 EFI parts for the '89 it was an ECU harness problem.

Anyway, your situation reminds of what others have run into. Here's one offhand that might help....

https://www.yotatech.com/forums/f116...estions-97787/

You might try and contact the fella who did the swap with success.

Sounds like to me you have a component problem and not a compatibility problem. I'll do some more digging, though.

mattsmopars

I went out to the shop and did the AFM test from 4crawlers and it passed the static test with no issue. Then I went on to the dynamic test. Test one was good. Test 2. starts out with about 300 ohms and should go up as it is moved open to no more than 1000 ohms if I read it correct. I am getting an OL. shortly after opening the gate on the AFM. The other AFM I have from the 90 model truck has the resistence to high at the begining of the test. It should be 20-400 ohms between the E2 and the Vs and it is 700 or so to begin with. So i am thinking that both of them may be bad. I can plug in my original AFM with the key on and in the run position and it does kick the fuel pump into run mode when opened. So would it be the computer shutting down the engine due to the bad AFM reading?
As far as the electronics I am pretty much back to everything original from my 89 truck. The original computer,engine harness, complete throttle body with TPS, the cold start injector,and vacuum switches on the valve cover, and the air box and AFM.
The only thing that I am using from the 90 model is the complete long block and intake with fuel injection, but the 89 harness plugs into everything as well as the injectors. Also checked them with a noid light to make sure they were working. Did not change anything else on the truck , was just replacing the blown engine with one from a 1990 model truck and first installed it with the 90 engine harness on the replacement engine.
Matt

thook

Honestly, I haven't looked at 4crawler's page in a good while, so I don't remember what it says. But, from my own experience with the AFM testing, neither OL readings or out of spec readings are acceptable and can cause definite running problems.

What's happening is the AFM is giving inaccurate voltage signals to the ECU, so the ECU thinks the measuring plate is open more than it really is and it's flooding out as with the '90 AFM. Or, the signal is just dropping out altogether as with the '89 AFM.....in which case, yes, it's shutting down. However, there's a resistor inside the AFM that's supposed to supply the VS signal if there should happen to be an open in the potentiometer/VS circuit. Possibly, though, the internal resistor is bad or the E2 ground it's connected to is bad since your engine won't run with the AFM in there. Which reminds me, have you checked the ground to your AFM? Not the ground E1 for the pump circuit, but the E2 ground on the harness connector. Those can back out with connecting and disconnecting and cause problems. If there's no problem with the connector, then I'd have to say, yes, the AFM's are bad.

mattsmopars

I have not checked the E2 ground is it just the therminal inside the plug to look at or is there a ground wire that bolts to the body on the drivers front corner? If so it may be possible that it is loss or not hooked up as it looks to have had a little body work in time on the Lh front corner.
I can tell you i made sure the grounds that tie into the changing of the engine have been double checked. Thanks for the help. matt

mattsmopars

The E2 terminal is grounded. I borrowed a upper air box with AFM from a friends 89 model truck that is running , and it made no difference on my truck. I still have the same issue that I was facing once the replacement engine started. i guess its off to the professionals.
Matt

thook

Damn, dude. I hate it for ya.

I called the Yota dealership yesterday to try and track down some wiring diagrams. I've got a couple of friends in the parts dept. They're perfectly willing to help and have the diagrams showing exactly how everything's routed just 'cause I was curious about your "extra wire" thing. I don't have a fax, they don't have a scanner, and they are 35 miles from me and I won't be that way (in the next town) until after the holidays. I don't know.....I figured learn something more about all that and could pass it along. Still can, but I guess it's moot, now.

thook

It's the terminal inside the plug I was talking about. I thought to have you check because it's happened to me before and had me chasing dragons' tails. It's happened to others here on YT, also. There's no peripheral ground, either. It's grounded through ECU circuits.

Does the vehicle start up pretty easy? Is the initial cold idle correct until the engine dies? And, the nature of the cut out...is all of a sudden or is it kinda gradual until it falls on it's face? And, have you thought to check the status of the coolant temp sensor and/or it's connection?

thook

Lastly, it's entirely up to you and what you're up for with this thing, but checking all your signals at the ECU connector will rule out if all component/sensor signals are even reaching the ECU accurately if at all. I'd hate to think you have any damage in the harness, but it does happen.

mattsmopars

It starts up easily and runs smooth for 5-10 seconds, so that is what makes me think the cold start injector system is working. It also idles nice in the beginning, but fades out till it dies. I did however finally get it to run some tonight, but it does not run smooth at all. I had to feather the throttle and it finally stayed running. The lower the rpm the more nerves it seems to run. No check engine light on even though it runs like crap. So i guess it is alittle progress. 3 nights work to change out the blown engine, and a week of night to finally get it run alittle. I don't guess that is to bad...LOL
Matt

thook

Okay, yeah....sounds like the cold start system is fine. Why don't you test the coolant sensor out? It is a possibility.

The easiest way to test it is to probe the back of the ECU connector at the THW and E2 terminals with the motor running and watch the volt meter to see if voltage drops steadily. But, since you can't keep the motor running easily, the next options are to probe the back of the sensor itself and feather the throttle if you think you can do all that safely. Or, just yank the sensor and test it for resistance drop in a pot of water on the stove. That's easy, but you gotta plug the hole up while testing. And, you'll lose a little coolant in the process.

mattsmopars

One other thing, As I stated before I reinstalled my original engines complete throttle body. I noticed that is was very covered with black carbon on both side of the throttle blade. I had to clean it real good before I installed it agian.
Do you think this would be a good sign of over fueling due to a bad coolant temp sensor? As i did put the one from my original engine in the 90 model motor becaus the guy who pulled it from the other truck broke the one in the 90 model engine. Thanks a million.
Matt

thook

Well, air coming through the throttle plate comes only from the air filter and intake tubing......well before the combustion process. IOW's, the injectors are pulsing right down into the cylinders, and manifold vacuum keeps the combustion gases drawn down into them and out the exhaust. So, no, it wouldn't be a good sign of over fueling. The dirty TB would mean someone hasn't kept the air cleaner clean regularly, and/or hasn't cleaned the throttle body very often, and/or the EGR is leaking, and/or the EVAP can needs servicing.....which is not very common. A better indicator of a rich condition would be soot on the spark plugs, exhaust, O2 sensor, valves, and pistons.....the latter two being impossible to see without pulling the head. Of course, carbon on the valves and pistons can/usually does also come from oil residue......ie, leaky valve seals, piston rings, and PCV.

More later............gotta go.