Oregon'sLoneWolf

The problem must be the ignition system. I think. I have to confirm fire at all coils first.

I cleaned all of the plugs, still no start. My guess is it has to be an attachment at the ECU either a ground, or a loose wire in my E5 plug as this has the controls to the ignition and grounds. There are also 3 BR wires in there I could have messed up. I did struggle getting the plug to lock and snap and I did have to shove the plug into the slot more than I wanted to. Thinking out loud, I am guessing I shoved one of the wires out of the slot when I plugged it in or something. It could very well be something in that plug.

SacRunner

As a part of my conversion harness, I soldered a number of ground wires from the 3.0 body harness to a number of ground wires from the 3.4 engine harness, then soldered one extra wire to that group (it was a re-purposed ground wire with ring terminal from the donor's dash harnesh) and have it connected to ground between the ECU mount and the body. I wasn't sure (and still am not, FWIW) where or how the ECU is actually grounded, so just to be safe, I added my own, and so far so good.

vital22re

iTrader: (2)

This motor is a non interferance motor. You won't bend any valves. Also, you can get away with just pulling upper cover and the dummy water pump. From there you should be able look down at the crank timing sprocket and see it lines up with the timing mark on the oil pump housing.

Oregon'sLoneWolf

Thanks Vital for the info, I guess I'm happy it isn't a Honda. And yup, all the timing marks lined up at the cam sprockets and the crank sprocket. It must be in time. Any reason why it wouldn't be?

Oregon'sLoneWolf

Here we go now. I am still baffled as to why it won't start as I have double checked the plugs at the ECU and put a brown wire back into the plug that had been pushed out due to the plug not locking on the back. Still crank, but no start and backfire. The wire was at the E5 24 spot for function E1. Whatever that is for.

It is getting spark as it is backfiring. So I guess I can rule out the crank sensor and cam sensor........I think.

I have yet to check my fuel pressure with a gauge but I know it is getting some as I didn't have the hose clamped down in the beginning on purpose to show me it was getting fuel. I also cracked the fuel banjo bolt on the rail and cranked. Same thing. Also, it is backfiring still into the exhaust. I will just have to check each wire. I have to remember fire, fuel, compression. I sure hope the yard that sold me the engine didn't lie about the compression!! Yes I have the right double electrode plugs.

So from my understanding, a backfire could also be a result of a poor air fuel mixture....running lean I think. As it has been sitting for so long, it might be lean do to gummed up injectors....seems to make sense. I had it on my list to by a scanner and plugged it in an it threw the code P0100.........MAF and a mention of a misfire. (clogged injector, poor coil?) Well, the MAF controls air, so I guess that makes sense. Also, I picked it up on Craigslist from a guy that said he bought one from a yard and it wasn't the problem so he sold it. He may have just sold me the one that didn't work. But, the MAF might work, but I have the wires messed up somehow at the ECU.......not sure how though. I have read that a faulty MAF would keep an engine from starting. I'll search for a way to check the MAF. Then I am thinking, isn't the throttle position sensor connected to the MAF? good grief.

Then it donned on me sitting here that when I had the engine inverted to do the oil pan etc, that oil had poured into my exhaust and I didn't check all of my plugs to make sure they were clean. I am sure this could cause a misfire. Anything else the oil could have gotten to that would keep it from starting?

Oh wow...what a puzzle!! As I am still learning, is my thought process on this correct? Will it start without a MAF? Meaning, can I check the Fuel Injectors and coils and if I have found a problem will it start when fixed without the MAF? My guess is NO.

cr@ves4wheelin

When I first started mine recently, it also back fired and ran like crap. I read the code, and it said the MAF circuit was open. I got it off ebay, and I thought I had wired everything correctly, because even the colors were the same for many year toyotas. But after checking the continuity on it, it turned out the pins on the connector, were in the wrong spots. After that it still stumbled, but got better. So then I got my o2 sensor and vapor pressure sensor wired in, and it ran great after that.

I'm at the same place on my 3.4 swap as you right now. But your wiring harness was professionally made, so I guess I'd rule out wiring til the end, but doesn't hurt to check. You can also check the fsm on how to test your MAF.

Also maybe check your spark plug wiring. I also got those on ebay, and it turned out that half of em didn't have the metal connector to touch to spark plugs inside. I was surprised that mine even turned over. Keep letting us know how it goes, I'll read through your thread and subscribe. Maybe I can help out.

SacRunner

My best guess is that E1 stands for "Earth 1" with "earth" being a fairly common alternate name for "ground".

As for your current issue, I too would suspect the MAF. Type the part number into Google and look for the result from Toyota Part Zone; they typically will show all application where that part is used. Then look to verify that your year/make/model/application of ECU is listed in the where used list.

From there, I would consult the FSM (not EWD) for your ECU's application and there should be a diagnostic section in there, look through it for similar symptoms and look up the P0100 code, and they will give you some additional trouble shooting advice.

Oregon'sLoneWolf

Hey man. Good point on the wires!! I too got mine off ebay and they kinda don't feel like they are getting a strong connection inside there. The coils just seem to lay in the hole. hmm I will know when I do the spark test tomorrow. About the MAF. I will look into testing it as after I cleaned it with CRC MAF spray and resetting the ECU at the battery and clearing the code, it popped back up. It should start without the MAF though. Glad you got your's figured out. Funny how your pins were wrong. I envoy you could figure out the EWDs. I tried, but my brain just didn't get it and there is a reason for that happening. I so wanted to do this all on my own.

Stick around man.

Oregon'sLoneWolf

Good to go Wallace......thanks. But the engine should start without the MAF I would think........it would just throw a different code I would guess. I will look into it. I will figure this out yet!!

vasinvictor

iTrader: (3)

Engine won't start without the MAF. It will act like it wants to, but won't. I'm 95% sure...

Oregon'sLoneWolf

First step is I have to truly confirm spark at all three coils. But if that isn't it......then I have a Haunting feeling.........there is a possibility when doing the valve adjustment that when turning the cams with the belt and crank shaft, measuring the shims, removing the cams to replace the shims and replacing the cams with the marks lining up on the sprockets, I did this process on the EXHAUST TDC mark and NOT compression stroke...............which would really suck..........but it would make sense if it has spark, fuel, and compression......I may have turned the crank once........but not TWICE..... and my guess is the timing marks on the outside of the case would still line up if it was set to the exhaust stroke. Cam moves one rotation for the cranks two rotations right to get back to Compression TDC right? Can someone please confirm my thought process for me???????

This could also explain the backfiring if it was from fuel leaking into the exhaust and igniting. (Wyoming mentioned this and it just now sank in as to why this is happening) Am I thinking of this correctly? In addition, when I had inverted my engine, oil came out the exhaust.

If it was set to exhaust TDC..........the marks should be facing on the opposite sides of the cam sprockets if I have it set to Compression TDC when I dig into it or So I think. Wish me luck. This sucks, but I have to admit, this trouble shooting is a good critical thinking exercise. I"m going to figure this SNOT out!!

Oregon'sLoneWolf

Thanks for chiming in. I had searched some YouTube vids and they had mentioned to just disconnect it and it would throw a code that is wasn't reading it, but it would start. I suppose the wiring is different for this rig.......Thanks again..........I think this is just one part of my equation though...please check out my next post as to the reason why if interested.

Oregon'sLoneWolf

Before I decided to dig into the top end to check the cam timing, First I had to complete the basics of Fire, Fuel or Compression in a NO START situation. First step in this process was to confirm complete spark at all three coils to rule out a complete NO Fire situation.....I know at least one works as I get a backfire.
I checked the coils for spark and the number three had spark, but 1 and 5 (in the cylinder order) did not. So, I had a no spark condition on two coils on top of the MAF code........my scanner did hint on a misfire too. Two wires without spark told me it was either A, a partial faulty Igniter, (not sure if that is possible) a bad connection to 2 of three IGT wires at the ECU plug E5 (most likely...that darned E5 plug) , or more disappointing, a faulty ECU. (very difficult to find one for 4X4 MT) Two of the options are spendy. BUT, my igniter was from a yard pulled from a vehicle left out in the weather. I"m starting to not like junk yards, but I only paid $5 for the ignitor so no total loss.


To check for a faulty Igniter or ECU, I found this diagnostic doc others might find useful.

------------------------

Circuit Description
The ECM determines ignition timing and outputs ignition signals (IGT) for each cylinder. Based on IGT signals, the ignitor controls the primary ignition signals (IGC) for all ignition coils. The ignitor also sends an ignition confirmation signal (IGF) as a fail-safe measure to the ECM. DTC is set when there is no IGF signal to ECM for 6 consecutive signals during engine operation. Possible causes are:

- IGF of IGT open or short circuit from ignitor to ECM
- Ignitor
- ECM

Diagnosis & Repair
1) Check for spark at misfiring cylinder. To check for spark, remove all spark plugs, and ground out each removed spark plug on block and crank engine for no more than 5 seconds. Test this method on each spark plug wire. If spark is present, go to step. If spark is not present, go to step 4)
2) Check for open or short in IGF circuit (Black/Yellow wire) between ECM and ignitor. Ignitor is located near MAF sensor. Repair wiring as necessary. If circuit is OK, go to next step
3) Disconnect black 10-pin ignitor connector. Access ECM behind glove box. Turn ignition on. On A/T models, measure voltage between ground and terminal no. 12 (black/yellow wire) at ECM E9 connector (see figure). On M/T models, measure voltage between ground and terminal no. 17 (black/yellow wire) at ECM E5 connector (see figure). On all models, if voltage is 4.5-5.5 volts, replace ignitor. If voltage is not 4.5-5.5 volts, replace ECM and retest.
4) Check for open or short in IGT1, IGT2 and IGT3 circuits between ECM and ignitor. Wiring colours for IGT1 is BLK/BLU, IGT2 is BRN/YEL, and IGT3 is BLK/WHT, and they're part of a 10-pin connector into the ignitor (which is on the right side of the engine compartment). Repair wiring as necessary. If circuits are OK, go to next step.
5) Access ECM behind glove box. On A/T models, measure voltage between ground and terminals no. 24 (BLK/BLU), no. 25 (BRN/YEL) and no. 26 (BLK/WHT) at ECM E9 connector. On M/T models, measure voltage between ground and terminals no. 23, no. 22, and no. 21 (same colours as above) at ECM E5 connector. On all models, if voltage is .1-4.5 volts, go to next step. If voltage is not .1-4.5 volts, replace ECM and retest.
6) Disconnect Black 10-pin ignitor connector. Backprobe ECM connector. Do same test as step 5) (three-wire voltage test). If voltage is not within specified range, replace ECM and retest.
7) Turn ignition on. Measure voltage between ground and terminal no. 9 (BLK/RED wire) at ignitor wiring harness connector. If voltage is 9-14 volts, go to next step. If voltage is not 9-14 volts, check and repair ignitor power source circuirt.
8) Check for open or short in wiring harness between ignition switch and ignition coil, and between ignition coil and ignitor. Repair wiring as necessary. If wiring harness is OK, check ignition coil - turn ignition on, check for battery voltage at ignitor and ignition coil positive terminal. If voltage exists, go to next step. If not, check wiring between ignition switch, ignition coil, and ignitor. Next, check ignition coil resistance. Replace ignition coil if not within specs. Replace coil as necessary. If coil is OK, replace ignitor.
-----------------

And finally, I can read a EWD. I just didn't know what some of the numbers meant as they were for pin number and plug number. daaaa Still don't think I could build a harness jumper though. I sure am hoping it is just a bad connection at two of the wires for IGT in the ECM. I am hoping to find .1-4.5 volts at the IGT wires in plug 5 to conform power to the igniter. I sure don't want to have to find and wait for a 4x4 MT ECU.

Oregon'sLoneWolf

----------Notes for above test

Step 5. IGT 1,2,3 of plug E5 check.
Voltage pin 21. .9 v
Voltage pin 22 .8 v
Voltage pin 23 .8 v
Within spec

Step 7 pin 9 at ignitor 11.4 v It's getting power.

Step 8 coil resistance check for primary and secondary...within specs

Conclusion.....bad ignitor. So far.

Oregon'sLoneWolf

Oh yeah, Earth makes sense. I think I recall reading once that this is the european name for ground. Brown wire......makes sense. I will work on spark first then move forward towards the MAF. Thanks man.

JasonYota

iTrader: (1)

Pretty sure when I was working on mine you need signal from the MAF before it will spark.

cr@ves4wheelin

The shielding just protects the signal wire from faulty readings that can come from a power wires electromagnetic field. So you can fix it, but it shouldn't render it useless because it's grounded from the ECU. An inch isn't that much either way.

You have three ground points for the ECU. Each of these ground points are for a set of sensors. One of these are for the ECU itself as well. One is located right next to the factory battery location on the passenger side. The other is on the driver side off the alternator harness to the sidewall. The last one is on top of the Intake Manifold to the firewall like the 3.0 had.

The first thing I would tackle is your ignition coils and spark plug wires, since you know there is a problem with them. I would:
A:Take them out and make sure the spring is contacting the coil and spark plug. And check the spark plug wires for continuity as well.

B: Take out the engine harness back out through the firewall. Using the DMM, make sure there is continuity between the correct pins on the ECU and the pins for the Ignition coil connectors. If there is no continuity, you might have the wrong pins. You might as well do the same for the MAF and Ignitor.

I've gone back and done this 3 times now, because whenever something didn't work on mine, I assumed my wiring was wrong. And 2 out 3 times, it was because I made a mistake wiring the thing.

Oregon'sLoneWolf

Copy that Jason, thanks.

Oregon'sLoneWolf

You had mentioned your MAF pins were in the wrong place. Can you share some info you learned regarding what pin numbers were in the wrong spot? Perhaps that is my problem as I had to pin these wires in the E6 plug at pins 12, 2, and 8.

Oregon'sLoneWolf

Great info. Regarding the ground points. I don't have one in the old battery location as nothing comes off of 97 harness and nothing comes off of the wire loom at the fuse box that I can see. I imagine it would be a ring terminal to a screw. Could this have been an old ground from previous battery location NEG terminal to the sidewall...which would no longer be there? Can you be specific as to where this ground comes from and to where please?

Second, the ground from my alternator to sidewall I didn't add as a part of my 3 big wire upgrades. I put the 8ga wire from the neg to sidewall. Is it necessary that it comes from the ALT? Yes, I would agree this is the better of the two ground points. I did leave the ground from the old ALT harness on the sidewall drivers side with flat large "spade" connector and the ground wire from that to the Manifold bolt on Driver's side. This in addition to the 4ga at the lower engine block seems to work OK. Back of engine to firewall.........CHECK.