backeddy

Hi everyone, first and foremost thanks to all who answer all of these posts.You guys are truly amazing! Now on to my problem and it really, really, has me stumped. I had a fuel injector firing problem and this is what I did to solve it (for 3 days) here is the list:

New (not rebuilt) injectors, fuel pump, fuel filter, removed and cleaned the gas tank (yuk), new fuel injector plugs and wiring (stripped the harness and soldered in all new, new pressure regulator, EGR blocked off, removed all of the plenum, throttle body and steam cleaned, new TPS, new cold start injector, replaced timing set, new oil pump, cleaned oil pan, new plugs, wires, cap, new maf. Basically if it was in doubt, I replaced it. After I assembled everything it ran *like NEW* for a whopping 3 days. Today it started popping a little bit then worse now it is back to EXACTLY like it was before I changed everything out. If I spray a little starting fluid in it, it runs perfect until it is burned off. I live in Hawaii and have limited access for parts so cannot swap ecu out etc. I rate myself as a good mechanic and understand fuel injection pretty well, but this one has me stumped. I have a bunch of family coming in ten days and I really need this rig running! Please help!

Terrys87

iTrader: (1)

I am guessing your harness connectors past the injector connections themselves. 2 injectors share the same wire. Here is what all I did on post #282. LINK https://www.yotatech.com/forums/f199...6/index12.html

Terrys87

iTrader: (1)

On my 88 runner build, last post I just put a pic up of them.

backeddy

Hi, I completely rebuilt the harness back to the module on the firewall and 1/2 way back to the ecu. I have even tried running a secondary wire out of the ecu direct to the new plugs....did not change running one bit.

Terrys87

iTrader: (1)

May have to start at the basics again. You may have picked up some gunkout of the lines. I have seen even the return lines blocked. How is the fuel filter? Can you loosen the Cold Start Injector and see if it is even getting fuel thru the lines. Are you sure the pump is operating? Double check its connections.

We had a guy one here a few days ago with new/rebuilt injectors and it was fualty. Maybe the same with the fuel pump.

Stu Pidasso

Have you tried putting a guage on the fuel rail to see if the pressure is adequate. You may also want to check on the vacuum line that goes to the fuel regulator. When you spray the starting spray in the intake you say that it runs well. I think that I would try to put a guage on it. Another thing you could do would be pull the fuel line loose from the intake/rail and then run the pump to see what kind flow you have. It may be like Terrys87 says, and you have some type of gunk in your lines. I know in the past when I dropped a tank and had my injectors serviced, I took carb cleaner and shot all my lines out with it. Best of luck I know you are frustrated. You sound like a pretty good mechanic I have faith in you bro.

backeddy

Hi guys, thanks will check the lines as I did over look that. I "think" I have adequate pressure because it is pretty fierce when i crack open the cold start connection while under pressure. I picked up a stethoscope today and had a listen...everything sounds as if it is working. There is not one place I have found here that has a gauge (fuel) so I am out of luck there. my vacuum gauge shows 20 inches or so at the regulator connection. Fuel filter is new and I did a bypass just to rule it out.....I will check the lines tomorrow, although I did air check them with about 60psi before I put everything back together. Yes, you cannot (well probably you can!) understand the frustration of it running perfect, started instantly etc....back to the symptoms that made me do all the work in the first place... So carb cleaner or ??? to clean the lines out?? I will washout into a white towel so I can see what was in there!

myyota

Check for vacuum leaks using propane or carb cleaner. Have you ever replaced the 02 sensor ?. If its original or has alot of miles on it, it could be bad. If you do replace it use a Denso 02 sensor. DO NOT use a Bosch 02 sensor, they don`t work in toyotas.

ChefYota4x4

iTrader: (5)

WOW, talk about DEJA VU! haha....

I've done most of what you've said, swapped out ECU's(3 of them!), etc., etc., ...... and I still, to this day, have a miss. NOTHING that would stop me from taking a 4000 mile trip... Just a weird 'pup-pup-puppup-pup-pup-pupupup' idle. BUT, now, it's begun to idle down on hot restarts only.

Anyway, I'm not looking for answers here, ... I'm actually bringing this up because something MYYOTA said struck a chord. "have you replaced the 02?" .... NOT saying it's the cause... but it could be wonky, especially if you did all this ether down the throat and flushing and then letting it plume out the back burning stuff off.. If an 02 is 'tired', working, but 'tired' at the point it gets bombarded with too much fuel or too lean conditions(both of which can kill an 02 AND CAT)... it can push it over the edge. There is testing withing the FSM. You might have replaced it....... but you hadn't listed it, so I thought I'd second that 'check the 02 at least' sentiment.

Also, think about it in these terms.. This is why I think my issue is either electrical/EFI or Ignition related........ I've gone through this thing 20 times... but there are still several things on there, including; LOTS of what you have, etc......

Yet, I tried 3 ECU's, ...and each time, the rig ran really smooth for a couple days... and then POOF, back to same old crap. The first time I rebuilt at 255K miles, 2 years ago.. the Top end was the cause of most of it, ended up being mechanical, ODD things, including a very strange CAM wear. This second motor in 12Miles since the original.. THE SAME MISS as when I had original motor in is STILL THERE! LIL 'PUP-PUP-PUP-PUPUPUPUP' haha.

I think my ECU's are all fine, the ones I have borrowed, etc., even my original.. But something they're reading, due to wiring, IGN, EFI in some way, is NOT HAPPY... So the ECU, after a couple days, just resets everything to 'safe' status, to keep me a lil rich, etc.

OF COURSE check the lines and stuff first, why not? It's free and you could reveal the culprit for all I know... It's just that your symptoms of it 'returning' after a couple days REALLY sound as though SOMETHING you have not replaced is still unhappy...........

Ignitor doesn't usually SLOWLY go bad... so it's not likely.. But it DOES control Pulse Timing of the Injectors to some degree, right? Off what? The reading it gets from the Secondary coil, right? Then the Coil shoots the spark according to 'contact' on each 'point'(in a sense) in the dizzy, right? That's all IGN and Mechanical Timing Related on ours. (maybe at least double check/test the Dizzy/Secondary/Air Gap/Coil/Ignitor too?

Best wishes, man... I'm starting to head back into this again, too... because of my most recent 'idle down at hot restart only' gremlin, haha.... WE'LL CATCH EM, just hang in there!

backeddy

Wow you guys are awesome, as that is another thing I did not even think about, I crawled under it tonight and there is the 02 sensor with 10" of a pigtail wire connected to nothing! Now the big question, where the hell does it connect to the harness at??? Praying that this is it.....

Stu Pidasso

Ok there is two locations that I have seen the 02 sensor. One is under the cab, you will see a place under the floor pan where the wires for the 02 sensor drop down. The under cab 02 sensor seems to be a 4 wire unit. Then there is another sensor that lands on the manifold/header under the hood. That configuration generally is a single wire sensor. That wire seems to come from the wire harness near the ignitor. Some trucks with aftermarket exhaust systems have had the under hood 02 sensor remoted so that it can mount on the exhaust pipe beneath the cab. I found my under cab wires just after the transmission cross member.

Terrys87

iTrader: (1)

I like to get mine at http://www.sparkplugs.com/ as myyota said dont get the Bosch or generic.

This is not a 100% sure check, but you said you were getting alot of spray at the CSI. That has always worked for me for checking for fuel at the injectors, one day it may bite me but that is how I check, so this leads me to thinking the injectors are not firing. It will run on starting fluid til it burns off. You are getting fire to burn the starting fluid. So I am thinking injectors, I really dont know if a O2 would keep it down, but now others can help with some ideas as well. Getting your O2 fixed is a good start.

When the wife gets in with the runner, I can try and get some pics if it isnt too dark.

Hello Stu Pidasso.. I was wondering where I had heard of Wendell, NC. It took me awhile, Lizard Lick.

ChefYota4x4

iTrader: (5)

I'm not positive on this, but unless your 87 was manuf. in 11-87 and is actually an 88.... I haven't seen the 87's with anything but the "on the manifold" 02 Sensor. I've only messed with CALIF. Emissions 22RE's, for the most part... So in 88, it should have, like Pidasso mentioned, a Heated 02 RIGHT BEFORE the CAT.... and a 2nd Bank 02 Sensor as well, BEHIND the CAT. I've also never seen an 87 with a heated 02... It was still placed on the Manifold so it would get hot fast enough and get accurate readings, right from the 4-1 Collection area, above the collector........

Here's my 87 4Runner's factory 02 Location/Single Wire.........



Here is the wiring connector Pidasso was speaking off, coming out right under the Cruise Control Actuator and wearing a Yellow Connector.......



Here is the comparison of the NEW-Aftermarket Denso 02 Sensor on the left and OEM original on the right(Original had a Shielded wire on the 02 Wiring side... The Newer ones, even another Dealer one I had, did not have the shielding any more).......



Here's where it is on my LCE 4-1 Header PRE-CAT Pipe(Which is where the 88+ had it located)......

Terrys87

iTrader: (1)

Thanks Chef, I forgot about that. My 88 is in the pipe Im sure and think the 86 is same as yours. Havent seen it in so long.

ChefYota4x4

iTrader: (5)

I second what Terry said.... Not likely that you'd have such dramatic symptoms from an 02 issue. MANY guys, for just a basic/generic test, will disconnect the 02 while experiencing their 'hiccups', just to see if it's POSSIBLY part of the trouble. But I don't remember hearing, "Yeah, my 02 burned out and now the injectors wont fire/and it wont run w/out starting fluid"..... Never.


FIRST, ..I gotta ask, cuz I'm a lil cloudy on something........ IS IT NOT RUNNING, AT ALL, WITHOUT STARTING FLUID? (Or just really rough if at all, when it chooses? Etc.). Please? lol.... Thanks, man, fill me in on EXACTLY what you're dealing with. Does it pop at all when TRYING to fire her w/out the starting fluid?

And yes, as said,.... You have firing up with Ether... so it's NEARLY ruled out on the IGN end.... (Only troublemaker over there for injectors, as far as I can remember, is the Ignitor).... And I did hear ONE CASE of the "Fuel Cut" system being toast... Actually, it was 'stuck'???? Can't remember off hand... Just know IT CAN cut the pulse to the injectors... so I'm curious if it can do it permanently.

A buddy of mine, we'd re-tore down the install of almost everything, cuz they used the wrong bolts, etc., etc... So after first start, he found POP->>>>> poppop, THEN NOTHING, lol. In the end, it was his Dizzy was 180* off.... And the wiring to one pair of injectors(as Terry mentioned/that you've apparently rebuilt) was toast/completely corroded to were it separated. Flipped the Dizzy 180* and it started, but ran on 2Cyls. Killed it and redid the wiring and voila, it was solved.

Guys; Does this system reach a certain point of 'limited spark' and shut off the injectors? I believe it does it if the ignitor is dead, obviously,..they can't fire. But, .... I keep reading lately about 'cracked coils' that cause HUGE drama and are very hard to find/diagnose, as they don't throw a code/wont necessarily DIE, literally... But can become weak or 'sporadic'...

Anyway, keep fishing, man! I think the 02 IS good maintenance, and YOU DO want to run it unless you want to always be in a sort of limp mode that's sucking more fuel, ya know?

backeddy

Thanks for the pics! Mine actually has headers and the o2 is just before where the cat would be (gone no emissions here). As far as running, yes it will start and even go around the block...on 2 maybe 3 cylinders...popping, no power etc...

ChefYota4x4

iTrader: (5)

Ahhhh, that's VERY different than 'wont run unless getting a shot of ETHER'... which is what I was thinking.

..... I would think, right off, by what you're saying, "What Terry Said".... pertaining to the Y-Connections to injectors... BUT, since you said 'I rebuilt the whole harness there, including the Y-connectors(RIGHT?)"...... then I would be inclined to steer away from 'wiring harness' drama.

Checked the pins at the back of the ECU connectors? NOT uncommon, when pulling on those, etc., that they can become 'backed out'... Worth a check, right?

When it's doing this.... Check the No.10, No.20 Pins at the ECU per FSM instructions and MAKE SURE you're not getting 'NOTHING from 1 and 3 or 2 and 4, or whatever it is, ya know? While you're there, you can check for a pin backed out the ECU? Also, give the ECU a good wiff...... JUST FOR THE HECK OF IT... Not common they go bad, but since you've not tried that, it's free to smell things, right? hehe... I hear they get a bit 'smokey' in there when they burn a board or whatever.

The way it's running... hmmmm. Just odd that it smooths right out with Ether. I would say that at least LEANS toward a couple injectors not firing intermittenly/or constantly... When you add ether, NO INJECTORS NEEDED, ya know? So maybe that's just making up for the 2 that are not firing?

I'm not sure on something.... But the Injector Resistor... It's not able to go 'HALF BAD', right? hahaha.... Even if it did, I would think it would cause TOO much FULL TIME WIDE OPEN INJECTOR PULSE action all the time, not too little.

HATE GREMLINS...... I would like to offer, if you fly me out of course, to come help you hunt for this gremlin... IN HAWAII! hahahaha. JK, obviously... But I DO wish I could lend some hands on help, man... KEEP HUNTING!

will101

Have you checked the intake gasket or intake for cracks.

Terrys87

iTrader: (1)

On that one link I posted, I would check all of your grounds as well. Since it will go around the block. I was just into my injector harness and it had #3 broken from those little "Y" connectors.

Even if it isnt broken it will pass a resistance check and my guess it is so corroded that it wont pass any or enough voltage to set off the injectors. I seen you rebuilt your harness, just wondering if it isnt broken again by chance.

backeddy

Hi....ok everybody, I took it ALL apart again, when I pulled the injectors out of the fuel rail....viola, Hawaii red gunk....took and cleaned the injectors (made my own rig up) and clean all of the hard lines with brake cleaner backed by air and the return line was pretty dirty.....put it all back together and it fired right up...so we will see how long it lasts this time....I do have a question though, HOW is this dirt getting past the filter and into the injectors? is there a better filtering system setup? I already have the filter remotely mounted. do I need to add an in line filter to the return line as well? Once again, thank you ALL for your input, this resource is invaluable for us DYI guys!