AnthonyVB

Just finished a 3.4 swap, 99 engine into a 95 4runner 4wd Manual, worth noting the 95 sat for 8 months as I found a donor .and did the swap. I'm running a 99 MT 4wd ecu, and I had Toyonlyswaps do my jumper harness. When I went to start it it ran great no sputtering or missing ran great. Drove it without exhaust (load as hell), but it drove fine. I welded the flange on the headers and bolted up my exhaust without a muffler just the cats still ran fine. This is over the course of 1-2 weeks.
I drove it after I did out the pipe on it drove fine still, hit rev limiter and roasted the tires easily. I went on approx a 30 mile round trip up and down hills and I loved the power increase. I got home the same day and welded a flowmaster on (with the battery connected). Then went to back out and give it throttle and it died kinda like I stalled it so I tried again to drive it and it sputtered stumbled and the idle would die down then I could keep it rubbing with the throttle barely, but would here some weird buzzing from the ECU area.
I barely got it back home. Over the course of a few weeks Ive done the following.
-Blew the main fuel line out with air thinking it was dirty fuel then test drove it and it ran great again and then half way around the block it started bogging out and sputtering again. That's when I replaced the filter and pump.
-Checked the Evap and return lines, they were crossed, I switched them and it wouldn't idle it barely started. I had fuel coming out of the evap breather hose and I drained the evap box of most of the fuel I could get out.
-Replaced fuel pump
-Replaced the fuel filter
-Replaced the Fuel pressure regulator
-Checked fuel pressure (35-40 psi @rail)
-HotWired the Fuel Pump
-Traced all wiring to make sure it wired properly. According to TIS wire diagrams I downloaded.
-Warrantied out the MAF, that was brand new.
-Checked the COR and its wired right.
-Checked
The problem I'm now having is it will start for approx 15 seconds takes a little longer to start than normal, it will ref to 1200 rpms drop to 900 then gradually die a long painful death 😂.
I'm so discouraged and annoyed. I plan to clean the injectors, clean the IAC, and replace the PCV valve. I'm getting a varnish smell from the engine bay somewhere but I can't pin point it. I did get some varnishy gas smell from the TB and the intake when I replaced the FPR. Any input is welcome I wouldn't be coming in here if I hadnt tried everything I could possibly do. Thanks ahead of time.

Oregon'sLoneWolf

I don't know anything, but you had mentioned that you hot wired your fuel pump........somehow I think that might have affected your COR wiring.? From all that I have read, I think the problem lies with your COR and this might just be it.

AnthonyVB

I just hooked it to a switch and 12v source to run it manually.

david braun

Not sure if this will help but a couple COR diagrams
98 Tacoma COR

95 4runner COR

Oregon'sLoneWolf

I see and this was mentioned in a past thread, but I"m thinking fire and that could make for a very bad day if you flipped over or had an unfortunate accident. Just a thought as I'm not sure I would want the pump to be running if the key is turned with the switch on and something happened.......but that is just me I suppose.

Did you get things straightened up with the evap can situation? I recall a thread(s) where your symptoms are very common.

AnthonyVB

I just hot wired it temporarily. I hooked the evap up correctly too how I've found it should be. I'm not sure how the evap box would affect the mixture and idle

vasinvictor

iTrader: (3)

I suppose you've checked your fuses? If you welded that muffler with the battery still connected, I guess it's possible that the ECU was damaged. At least blew a fuse that power the 12v to the ECU. Usually in cases like this, the problems ends up being a ground wire somewhere or a loose connection. I would call Toyonly and tell them what you did and see if they have any suggestions. That's most likely free and reliable advice right there.

SacRunner

When my 4Runner was having a bumper built, the shop attached some kind of isolator to the battery to keep any extra current from the welding process away from the truck's electrical system. I only bring it up since he said that after replacing one fried ECU, that isolator is cheap insurance.

My point, see if you can track down another ECU and see if that fixes, or even just changes your issues. If you managed to fry your ECU, you may have fried other parts too, but better to start somewhere.

This of course is assuming you're not throwing any codes.

AnthonyVB

It was throwing codes 0110 and 0100. The reason I rule out electrical is because it started running terrible and bogging down so I blew out the main fuel line and the thing ran like a dream. Like j said I roast the tires and hit rev limiter. Then half way around the block it started doing it again, when it was bogging down and falling on its face I was hearing a weird buzzing from the ecu.

AnthonyVB

Well its not the ecu. I plugged in the 2wd AT ECU I had laying around from the donor and it did the same thing no difference. Something worth noting as well is even of I lightly touch the throttle when I starts up to try and get it to stay running it dies instantly.

SacRunner

Glad you were able to check the ECU with another you had.

I'd look at the MAF and the wiring between it and the ECU. P0100 is a MAF malfunction and P0110 is the intake air temp circuit malfunction.

http://www.obd-codes.com/p0100
http://www.obd-codes.com/p0110

It kind of makes sense too, if the MAF isn't working right, when you touch the throttle, it's going to open the throttle body and pull more air in, but if the MAF doesn't read that there's more air rushing in, it may not inject more gas, so it'd lean out and struggle to keep going.

AnthonyVB

Bump tried a lot of tracing today still nothing really.

vital22re

iTrader: (2)

sounds like a fried maf. Disconnect it and try running it.

AnthonyVB

I've replaced the maf already

vital22re

iTrader: (2)

does it still throw the maf codes?

AnthonyVB

It did because I pulled the maf plug

sphealy

iTrader: (1)

I would think that its something as simple as a loose electrical connection or vac hose. You said you roasted the tires and hit the rev limiter... if a connection was loose its possible that the bumpy ride unhooked it for you. The easiest way I have found to locate loose connections is start it up and give each section of wires the shake test to see if you get a change in the way its running. Might not work in this case since it appears to be ok at idle but you never no.

sphealy

iTrader: (1)

Any word on what the problem was?

AnthonyVB

Hey sorry guys yeah I got the problem solved. So the original culprit was the swapped evap and fuel return lines. In the process of trying to fix that I moved my fuel hard line away from the exhaust crossover and it put more tension on the rubber high pressure line which then kinked it. As simple as a kinked fuel line.