I have a 1988 toyota pickup 3.0 4x4. Has another 3.0 from unknown year truck. Truck has been very hard to start lately, and have to crank it over for about 10 sec before she starts and keep my foot slightly on the gas pedal. If I dont give it gas it trys to want to start but immediately dies when I release key from start position. Checked for Cel and got a 43. Truck was also idling very low like 500 rpm but I recently adjusted timing and cleaned throttle body and it now idles great at about 800. Once started truck runs great, and doesnt have much trouble starting back up when warm, my problem only happens on cold start. Apparently from my research code 43 could be a multitude of things causing it but every post ive read their truck had different symptoms then mine, so before I start throwing money in it i wanted to get some opinions of what it could be. Is it the COR? Would that cause the problem im having? Or something else?

 

Wanted to bimp this, if anyone can give me a push in right direction. Cor was tested, and is good, recently have replaced my vafm (had this problem before replacing). Could it be my cold start injector? Temp is above 100 outside, so its not cold out. Ignition switch? Kinda at a dead end.

 

When you replaced the VAFM, was it with a new one, like new from the dealer "new", or similar, or was it a junk yard special, so just new to you? Did you TEST the new VAFM signal to the COR? Does that switch close as soon as the vane opens, even slightly, to activate the COR, and thus, start the fuel pump running?
Did you test the Cold Start Injector Timing Switch? It should be closed during a cold start. Remember, "cold" is a relative term. "Cold" to an engine, and "cold" to a human are two entirely different things.
Did you pull the cold start injector, and check that it activates and gives the correct pattern of spray when you crank the engine when cold? Pull it out of the throttle body, leaving the fuel line and electrical plug connected, place it into a container so you can see the spray pattern, if any, pull the center lead off the distributor, both ends of it, then have an assistant crank for a second or two. See the spray pattern from the cold start injector. Does it spray? Enough? Too much?

That's just a couple things I can think of right off the bat. Did you read the FSM Troubleshooting guide for the starting system portion of the entire Ignition System? I don't have time right now, but if you need, I can post it for you. But get an FSM, whether paper or PDF version. You need one!

Good luck!
Pat☺

 

You had it in front of you but didn't tell us. Now someone who is less lazy than me might go look it up for us.

Iirc 43 is no STArt signal at the ECU. STArt signal does things like powers the solenoid for the starter, triggers the COR, powers the CSI and in the 3vze does some "magic" inside the ECU (like for example use the startup maps for fuel and ignition timing).

So your starter works, your fuel pump cones on but the ECU just sees the engine as running really slow and poorly.

Two likely cause are a broken wire or bad connection, these maybe intermittent but are relatively simple to check for by back probing the STA signal at the ECU connector. Much less likely but still possible is an ECU hardware failure where the signal makes it all the way to and through the ECU input but something has failed internally.