jjman179

Hello all, i am new to the forums but have read and got several ideas from here through google searches. I have a 1990 extended cab 4 x 4 with the 22re engine for starters. I bought the truck roughly 1 year ago knowing that the motor had to be rebuilt due to the timing guides and tensioner breaking and it still being ran like that for quiet awhile until it eventually stopped running. I pulled the motor and tore it down to bare block, i did not replace everything but close enough. For example the pistons and rods where fine, but i did replace the piston rings and had the cylinders polished up. I did have to put a new crankshaft in, and i did buy a new one, not a salvage part. Anyway long story short, the motor has been back in and i have a few plugs on the wiring harness that i can not locate, and i have not put the air intake tubes on yet as i figure it should start and run with them off as long as the Mass air flow sensor is plugged in. It starts right up and dies right after, which i have gathered is the cold start injector. I have put all new grounds on where they should be, the plugs that i mentioned earlier that i have not found where they go yet is the one 4 prong plug at the end of the loom the just contains the 2 O2 sensor hookups. The other is a 2 prong plug that is in the loom with the injector plugs and i seen a pic on here that said it is not a necessary plug. I have no idea how long it had sat without running before i got it and when i checked for fuel pressure ( which it had alot of initial pressure, but when that is released not much when i am turning the motor over) the gas smells so old. So i plan on draining the tank, I am just looking for ideas as to where the plugs may go and what should be my next step to getting the truck to run? I apologize for the long post, just trying to give as much history as possible. Thank you

gdavis67

Just finished putting a new motor (22RE) in my truck as well. I think your plugs are this:
1) 2 prong on O2 loom should plug into the transmission on the top drivers side of the trans. - at least it does on the 5 speed.
2) Second plug should be the VSV valve on top on the valve cover. There are three vacuum valves there, but only one is on the same loom as the injectors and that is the VSV plug.

Your start, run for a couple of seconds, then die issue may be your circuit opening relay. It is in the passenger footwell, behind the kickpanel and just above the ECU. Mine did the same thing - replaced it and all was good. You can put a jumper wire in the diagnostic port (engine bay, passenger side by the fuse box) from the Fp to B+ plugs and that will fire the fuel pump when the key is on. If that works, chances are it is the C.O.R. Do a search on Circuit Opening Relay to see more.

jjman179

Still having a nightmare with this truck. I have power to every wire, even grounds, at every plug on the wire harness. Have tore the harness apart looking at all the junctions and they all look great. Odd thing is i have power to everything even with the key off. Only way to not have power to everything is by pulling the IGN fuse under the dash. Any ideas where to look maybe? I have tried a different ECU that is known to work, same numbers as mine. I just have no idea where to even start looking for how there is a short circuit.

Old_ blue

you need to hook up the intake tube to your air box. Its a vane airflow sensor and is very important to your fuel trim. incorect vane air flow reading=incorect fuel=no run. make sure you hook it up tight. Then do you timing,idle and all that fun stuff.

jjman179

had all the intake tubes and everything hooked up but the injectors never spray fuel. The cold start is what starts it then it dies. Have tested the injectors and they are not getting the intermittent ground from the ECU. Thats why i tried a working ECU but same thing. We have ran it on starter fluid and it runs fine, just the short making every plug hot is somehow not letting the ECU send the ground signal to the injectors.

RJR

The truck won't run without the air intake hooked up. The vane air flow meter requires air flowing through it to activate the fuel pump after you release the key from START. No air flow, no fuel pump, no run. That's a safety feature to kill the fuel flow in case of an accident where the key stays on but the engine stops.

The fuel pump runs as long as the key is held in the START position, and the cold start injector will also supply some fuel briefly, but once that's over you need the AFM hooked up.

For diagnostic purposes you can jump Fp to B+ in the diag connector to force the fuel pump on whenever the key is ON. If that gets your truck going you've identified your problem. Just remember that defeats the safety feature.

Sorry, just read your last message that the intake tubes were hooked up. You might still try the Fp to B+ short to see if that helps.

Old_ blue

hopefully you have a wiring diagram....
You could check d12 and d15 on your ecu to see if there is still supplied voltage and the computer is not switching off your injectors (on). or you could do an ohms check from your computer to your injectors. Looks like the voltage is supplied by the igniter? if the injectors have a good circuit i would look for something the computer would see that would make the injectors not fire. not sure of any inputs that would make the computer not want to activate injectors but there might be something codes?

jjman179

i will get the code i pulled tomorrow, i have it wrote down in my manual.

jjman179

Code 25 Air/fuel ratio LEAN , which makes sense seeing as the injectors never spray. What has me so stumped is having power at every plug on the harness, and every wire. Not only that but some are different, some have 12.5 volts and some have 9.5 volts. Next to the ECU is 2 other plugs, a white kinda clear one and a Grey one that all join in the harness with the ECU wires and go to the engine compartment. If we unplug the grey plug, nothing has the Juice to it. Oh and every wire is juiced even with the key off, maybe ignition switch?

jjman179

Everything from the injector plugs to the computer checks out fine.

PapaChulos4U

The "kinda white/kinda gray" plugs need to be plugged in. They go into the plugs above the ECU. You will have to remove the passenger side kick panel and the glove box. If you don't plug these in, you will not have a complete circuit. Then engine will crank, but will not turn over. If these do not work, your COR may be shot. You do need to make sure the VAFM is piped, too, but it looks like you got that rectified.

scope103

Are you sure it's the injectors not opening, vs. no fuel pressure? You could purchase a commercial "noid" light to check for the injector pulse, or you can make your own from an LED and a 10k resistor (you can even buy those already made up). And you can put a mechanic's stethoscope on the injector to listen for them clicking.

A lot of the other advice (jumpering FP to B+) is very good advice to confirm that the fuel pump is running, and you don't have a VAF/COR issue.

jjman179

Yea have had the injectors and fuel rail pulled, held an injector in my hand and got not 1 click, jumped it with a hot and it clicked several times. As far as fuel pressure, i have taken the top banjo bolt out and held my fingers over the tube, soon as you crank it over you have great fuel pressure. I checked the COR and put a known good one in, then read that if it was that i wouldnt have fuel. The fuel getting to the rail is not the problem, just something stopping the ECU from operating the injectors.

RJR

When you say you have "power" on all of the pins of every connector, be a bit more specific. What do you mean by "power"? 12V? Which connectors?

Having +12V on most connector pins is indicative of an open ground on that section of the wiring harness. Take your multimeter and, with the IGN fuse pulled (to get rid of the power on the harness), measure the ohms from a ground pin in the harness to the truck frame or engine block. Should be 1 ohm or less. I suspect it will measure much higher. If so, you need to find what's unplugged in that part of the harness, and get your grounds hooked back up again. Could be the injector grounds at the ECU are open.

jjman179

Yea 12v power, i can take one lead from multimeter and put it on any pin and the other lead on the valve cover and i have 9.5v on some and 12.5 on others. Been months on this and my dream truck has turned into a nightmare lol. I will admit i am not that savy on electrical problems. Really looking for advise as to where to start.

RJR

Start where I suggested, by measuring resistance from one of your ground pins in the harness to the frame. Go to the ECU and measure resistance from its various ground pins to the frame. One or more is probably floating. Figure out why, fix that, and you'll probably be good to go.

jjman179

messed with it again yesterday, only thing new i noticed was i had the battery unhooked, hooked it back up and had no power to any of the connectors. It was after the key was turned on for the first time i had the power back, regardless if the key was off or on. Also i have a Haynes manual and some of the wiring diagrams are not to good, does anyone know of any online that way i could be sure what wire on each plug is, hot or ground please.

PapaChulos4U

What do you mean "regardless if the key was off or on"? I don't understand. The only things that should work with the key "off" are the brake lights and headlights. Everything else kicks in when the key is turned to the ACC position.

Did you connect the two plugs to the connectors above behind the passenger kickpanel? I installed an amp the other day and disconnected these to run speaker wire then couldn't get the truck to start. After I realized I'm an idiot I plugged them back in and it fired up good as new. Is your distributor off 180 degrees? It's fairly easy to do.

jjman179

Yea thats what has me stumped, after the key is turned on for first time, it does not matter if it is off or on, everything is powered all the time.

PapaChulos4U

Sounds like your main 12V is making constant contact with the ignition box. It may be overloading the entire electrical system and causing everything to shut down when it gets current. I would check the 12V wire and make sure it's not making contact with anything else in the system. It could also be the ECU. Ensure the voltage there is correct.