I swapped a 3.4 from a 99 tacoma into my 95 4runner and used a harness from toyonly swaps.
The motor runs for about 3 seconds and dies.
Toyonly swaps said I didn't have to do the COR wire add but I did it anyway with the same result.
I have a new fuel tank, fuel pump and filter. I've bench tested the COR, the EFI relay and the MAF sensor and all have tested good.
I've verified and re-verified my vacuum line connections so I've about exhausted all the options I can think of.
Since the motor does run for all of 3 seconds I'm thinking this is probably not an ignition issue???
I have pulled 2 spark plugs and verified there's plenty of spark. I will check the other 4...
I've also verified that I have good ground to the engine.
Any recommendations / suggestions would be appreciated.

 

Most usually it's a MAF issue. Confirm you have the right style MAF for your swap. The early 98s had a cartridge style. The late model 98s, sometimes called 99s had the drop in style. Confirm which one TOS wired up for you. If this does happen to be the issue, they should be able to tell you which pins to swap (it's 3 pins IIRC) to swap to get your MAF working. Other than that, could be a fuel pressure issue, but you should be able to keep it going with starting fluid if it's fuel issue.

 

Thanks for your input. I have the drop in style MAF. I'll ask TOS which one they wired up.

 

How does it die? Does it sputter out (like you've run out of gas) or is it an immediate shutdown (like you've turned the key to turn the engine off)?

I had a strange, intermittent start then immediate stop problem that I thought was fuel related, but it ended up being a loose wire in one of the ECU plugs (IGF). After months of debug and replacing possible parts, I ended up wiggling various wires in the back of the ECU connector until I wiggled one and it immediately turned off.

 

It just dies. After 3 attempts it begins to flood. Toyonly swaps thinks this is either a MAF or a wiring issue as you indicated. Since the MAF tests good I guess I have to begin continuity testing the harness.

 

OBDII Code???

 

I got my hands on an Innova 3100i code reader. When I hook it up and turn the key to the on position there's a brief flash on the reader indicating communication but it goes off almost immediately so there's no sustained communication with the ECU. I'm thinking I may have a bad ECU. Can anyone recommend any testing I can do to verify I have a bad ECU?

 

A bad ECU on these Toyotas is highly unlikely, though remotely possible. I'd look more info your wiring, like making sure you have b+ going to ecu.

 

I'm using a toyonly swaps harness but I'll definitely look into this. Thanks

 

I have 5 wires hooked up to the E5 connector. These are listed below slong with the voltage read at each wire with ignition in off and on position. Do these voltage readings look correct?
E5-8 sil key off 0V key on 0V
E5-12 sp1 key off 0V key on -12V
E5-14 batt key off 12V key on 0V
E5-23 +B key off 0V key on 0V
E5-24 BK key off 0V key on -12V
I'm going to send this info to toyonly swaps in the morning but I thought one of you guys might be able tell me if this looks correct.