Jbiggs

Ok yes I am new to this site, I have a 95 4runner 3.0L auto that I have been working on. I have installed headers, egr and pair valve delete, new cap, rotor, plugs and wires, new injectors. It ran before all of this work but now it will not start. I have no spark and no fuel. I also have only 1.1v at +B on the Diagnostics connector plug with the ignition on. I did run power to FP from the positive side of the battery and the fuel pump does work. I check the EFI relay it is good. I have read alot of the threads and I am leaning towards the ecu but not sure? Any other suggestions?

87-4runner

It was running... you did some work and it won't start? Turns over but no start? Won't turn over?
why do you think the ecu would quit working out of the blue?

Jbiggs

Yes it turns over but wont start. I found part of the wire harness on the right side of the engine compartment that hard rubbed and wires were bare and sitting on the alternator, I repaired the wire and ohm out the coil and distributor both are good. Checked all my fuses all good, efi relay was good. Afm or maf was also good.....

87-4runner

Are you sure it's no fuel and no fire? That have you done to verify that?

Jbiggs

I have verified no fuel pumping and no spark while cranking.
I ran 12v to the FP on the diagnostics connector plug and the fuel pump came on and fuel was pouring out of the return line, I pulled the coil wire off the distributor and a plug while cracking, no spark

Jbiggs

I also checked my ground connections and they are tight and still connected, I read on another thread to check for 12v on the +B on the diagnostic connector plug with the ignition on and I only have 1.1v? What could cause a voltage drop?

Jbiggs

I also have no check engine light anymore, jumped E1 to TE1 and nothing no engine light. I also checked the gauge fuse and the was good as well

scope103

The alternator is on the "left" side. Left/right is from sitting in the driver's seat, not standing in front of the engine bay.

B+ goes straight to the EFI relay, so if you only have 1.1v there the ECU will never wake up (so no spark, among other things).

How did you "check" the EFI relay? Did you check for voltage on the pins in the relay socket? As with all electrical issues, you keep working backwards until you find the problem.

Jbiggs

yes the efi relay also has 1.1v in the socket. Also the alternator is on the left when sitting in the vehicle,

scope103

Well, keep going! Pin 5 of the EFI relay goes straight to the EFI fuse (15A) via B-W wire. EFI fuse goes straight to the battery (W-R). Measure voltage to ground on both sides of the EFI fuse (there are small metal tabs on the top of the fuse for just that purpose; you don't need to pull the fuse.)

And before you do that, put your multimeter on the battery posts, as a sanity check. If you get 1.1v there, either you have the most-discharged battery I've ever seen, or you're not using the meter correctly.

Jbiggs

I will check and let ya know, thanks also battery is fully charged i have it on a charger when I'm not messing with it, as for the meter I'm good, hvac tech for over 28yrs I have used many meters....just trying to track down what is causing my issue and where I haven't looked yet.

I do appreciate all the help and insite so far Thank you

scope103

And you've never used a multimeter, only to learn you had it set on the wrong range? A "dead" battery can sit on a charger for months and never get above 1.1v. Putting the meter on the battery posts is just a sanity check - you expect to see (about) 12.6v, and when you do, you proceed.

I'll mention here that 1.1v is problematic. There are no semiconductors near where you're testing, and very few Thenevin equivalent circuits. You expect to see either battery voltage, or VERY near ground. Not anything in between. So something has happened that HAS given you a voltage divider. You've got current leaving the battery and making a circuit that leads to a 11.5v (12.6-1.1) voltage drop at your test point. Something like a bundle of wires (with nicked insulation) that's soaked in salt water.

Jbiggs

hmmm, it's just strange that now I have an issue starting this thing. And yes I'm sure it may be something I caused...lol i am going to check some other wiring around where i was working.

as for using a multimeter I obviously misspelled a word in the last reply I have corrected that. And yes i know how to use a multimeter backwards and forwards😁

Jbiggs

Ok it's been a few weeks, sorry I have a lot going on like most of us.
well I found a bad 30amp fuse that controls the efi relay. I replaced it and got it to kick over but it shuts right off. I feel the new upgraded fuel injectors are flooding it out. I have spark, fuel and air. I have pulled the intake and injectors and I'm going to get another set of stock and hope for the best. I will let ya'll know.
I also picked up a 95 2wd, 94 4wd 5sp parts 4runner and a 95 4wd auto parts 4runner. I plan to swap the 2wd auto with the 5sp.

scope103

"Kick over but shuts right off" is the classic sign of a problem in the VAF-COR circuit. Fortunately, diagnosing that is the easiest thing you can do on this truck. Jumper FP to B+ in the diagnostics connector (this forces the fuel pump to run with key-on). If it starts and runs, you know where the problem is.

The EFI fuse SHOULD be 15a (and it should be labeled in the relay box). Using a twice-size fuse can cause the same problems it would in your house.

Jbiggs

Yes I have already jumped FP to B+ and the pump runs but never starts or trys to start. When I try to start it with out the jumper it starts but dies a second or two later and if I push on the gas it sounds as if it floods out.
As for the 30amp fuse it was a blown AM2 30amp fuse which feeds the efi relay, after changing that the fuel pump started working.
Also I have swapped out the VAF with 2 others and still the same results and I swapped out the COR and same thing. I replaced my injectors with ones off ebay so I'm thinking that is my issue.