dbryant1928

Just completed a 3.4 swap. The donor for the engine was a 98 limited 4 runner. The reciepient is a 93 4 runner. Got everything hooked up accordingly and when I start it, it runs about 2-5 seconds and then dies. I have a good pulse at the injectors as well as the coils even after the engine dies. I did not change the fuel pump out. Could I just not have enough fuel pressure to keep it running. Does anyone know the difference, if any, between a 98 3.4 and a 93 3.0 fuel pressure?

RobD

You should be fine with your 3.0 fuel pump. I've been running mine for over a year and 55 000 kms since my swap with no fuel related problems.

I would check with your circuit opening relay or your EFI relay. As a huge guess, I think you're probably getting power to the circuit opening relay, which sends power to your fuel pump, but as soon as you let go of the key, the relay opens, killing power to the pump and you're getting the last few seconds of fuel.

This is just a guess, but I'd start there.

dbryant1928

I ran a hot wire directly to the fuel pump just to see if this was the problem. Even with the pump running continuously it did the same thing. I checked the pulse at the coils and the injectors. There all good. I am going to check my maf etc. I really appreciate your help. Anymore advice would greatly be appreciated.

RobD

Do you have spark?

cartune777

well if your getting fuel all the time and spark it should stay running, i was having the same problem and it turned out to be what rob said, which sounds like your case

dbryant1928

I am tidying up my mass air flow tube, and double check everything again. I am also going to replace the fuel filter. I appreciate your input and I will be sure and post an outcome.

RobD

I got lucky.

But you need spark, air, and fuel. That's where you need to look.

dbryant1928

Well I found the culprit. I checked my voltage to my MAF and it was 0....So I ran a hot wire to my white/blue striped wire at the MAF and she fired up and ran like a dream. I am sure this all goes back to the efi relay since that is where the maf gets its juice if I understand the wiring diagram correctly. I am going to start again in the morning and hopefully take it for a test drive if everything goes well. I have done alot of modifications on different things, such as a 1968 toyota landcruiser fj 40, with chevy 350, muncie 4 speed, etc. But this particular swap (3.0 to 3.4) has made everything else look like childs play. I appreciate everyones help, and I will be sure and post my experiences from start to finish, as soon as the swap is officially complete. Until then.......

scuba

I if you think its that type issue, might wanna jump the COR wire, that could be your problem if you dont think the AFM is getting its juice...
Good luck

syber_kowboy

That sounds like what I would check. It could be that the MAF lead is grounding somewhere before it gets to the sensor. I would jump the COR as well but I think the EFI will work as well. At least it didn't take long to locate the culprit.

scuba

maybe the fuel lines are backwards....
Hey...It happened to me...