won't stay running after engine swap

[chevyjeff]

I just replaced a 22re in an 1986 4runner with a 22r out of an 1985. Switched everything over, intake, sensors, brackets, evrything. Go to start it and it will fire and run for a few seconds then die. It won't start right back up, but if you let it sit for 2 to 3 minutes it will fire up again. But same old cycle. I can hear the flapper in the airbox opening and closing as I try to give it gas. If you let the engine set a few minutes and then crack the fuel line all pressure is gone. If you crank engine while fuel line is cracked lots of pressure. Just need to know where to start. Any help would greatly be appreciated. Thanks Jeff

[alltrac165]

Could be you need to change the fuel pump. The EFI version uses WAY higher fuel pressure and that might be too much for your carb to hold back. Don't know for sure, just a guess.

[chevyjeff]

It is in the 86 with the fuel injection on it. I just took the blockoff plate off bad 86 engine and put it on the 85 motor so as to retain the intank fuel pump on the fourrunner. thanks anyways, Jeff

[alltrac165]

When you say you switched everything, does that include the computer? Also, you say you're still using the EFI fuel pump? Check the carb when you start the engine. If it starts dumping fuel down the throat, you might be overpowing the carb float with the EFI fuel pump. EFI uses around 40 psi and the carb only wants about 6 psi. You may have checked this, but I couldn't really tell from your answer. Or maybe you misunderstood what I was getting at with the fuel pump.