Won't start - no spark after rebuild

[jcarter]

Fusible Link: Aka, smaller wires part of the + battery terminal. When I checked, I put the + on the bolt downstream from the fusible link & - on neg of battery. If they were bad, I should have 0 volts or open circuit.

Brass screw: I'll check tonight after work.

Meter: Its a CEN-TECH Digital Multimeter. I don't trust the ohm readings on it. Seems the volts are fine.

Sensor in engine compartment: A likely suspect: I remember pulling something out near the Air Sensor (MAF or AFM). It had a bunch of delicate tinfoil looking stuff. I carefully put it back in and disconected something else to get that part off. I'm trying to remember. I'll look closer tonight. I'll be I screwed up something here.

EB1: I'll look at the fuse box per your description. It doesn't sound like I had to remove it and I don't remember disconnecting anything near the fuse box. There were the EGR connectors, then another connector or 2 that were line-to-line connectors near the EGR connectors.

More troubleshooting tonight. Thanks for the help.

 

[jonheld]

I remember pulling something out near the Air Sensor (MAF or AFM). It had a bunch of delicate tinfoil looking stuff. I carefully put it back in and disconected something else to get that part off. I'm trying to remember. I'll look closer tonight. I'll be I screwed up something here.

OK. If you unscrewed the 2 phillips screws that mount the connector to the body of the AFM and pulled that out, then that's your problem. By doing that you tore off all the connections inside the AFM. This could have possibly caused a short that is preventing the CEL from illuminating. It could have also blown the EFI fuse.
A quick check would be to properly remove the AFM connector by lifting up the spring tabs on each side and simply sliding the connector out. Once the connector is off of the AFM, check the EFI fuse (with a meter, not your eyeballs). If the fuse is good, turn the key to the ON position. If your CEL illuminates, then you've found the problem.
Source a used AFM from any 3FE motor (FJ62 or FJ80).

 

[jcarter]

Diagnostics over lunch hour



Brass screw: Hard to miss in fuse box. In pic has orange circle & white rectangle underneath (probably insulation since it's hot). 12.5V from there to - on battery. GOOD

EB1: See pic. Notice round, white, 2 wire connector in pic? Has black o-ring around it. I didn't take it off during the project. Actually, looks like it hasn't been plugged in for a while (dusty). What is it for? Where does it go? If this isn't EB1, what is?

Other connector: On DS near about #4 injector, there are some wires that come out of the wiring harness. 1 is big-eye for grounding of air chamber. Another small-eye ground/connection. Then there was another plug I couldn't figure out. Closer inspection shows it has a cap on it. Almost like it's supposed to plug into something for diagnosis. Found a pic, toward bottom a little right.


Tinfoil thing: Now I remember. There is a plug into the MAF, or black topped metal thing between the air filter can and air plenum to air chamber. When I was taking this off, I unscrewed the 2 screws holding it on, saw the tinfoil (delicate stuff) and carefully pushed it back in and rescrewed it on. Then I found the actual plug and unplugged it.

Thanks a lot for your help. I'm sure it is something I tore up during the project or didn't hook up right.

 

[jcarter]

AFM it is. Looks like were were posting at the same time.

Thanks again.

joe

 

[jonheld]

Good on you. Your AFM can possibly be repaired but you need to be good with a soldering iron. You'll need to cut the top black cover off the AFM and do your best to put the broken wires back where they belong. Several folks have done this with varying success.
IMO, getting a known good unit is a better option.

 

[jcarter]

HOLY CRAP! Those things are expensive!

Cheapy online places are for around $250! I'm checking with Cdan. Do you recommend OEM? Required?

Thanks for the help!

 

[jcarter]

Disconnected the AMF and CEL came on with the key. I should be okay, right?

Will it start with AMF disconnected?

 

[Timpanogos Slim]

That CEN-Tech meter is about $5 on sale at Harbor Freight right now. And they SHOULD work.

They may not be pretty. They may not be durable. But they should get the job done until you break the leads or something.

I've owned a few. It's annoying that they are not RMS meters.

If you get another, tear open the package and test it right in the store after you buy it. Ask for another if it doesn't read 0 ohms with the probes touching. If it reads higher than 0, it is clearly defective.

 

[jcarter]

Five bucks, sounds like me. . .

Do you know if the engine will run with AFM disconnected?
Got a line on a used one for $100. Need to make sure it fits and 8/92.

 

[Timpanogos Slim]

Sorry, I have no idea. My gut feeling is that even with a bad or missing AF sensor it should still turn over and maybe run badly. But I have no experience there.

 

[Timpanogos Slim]

I'm just saying, and i am not a mechanic, have never laid hands on a 3FE engine, that what the AFM does is tell the computer how much air is coming through the intake hose, and the computer uses that information to determine how much fuel to pump into the intake.

One would hope that the computer would interpret a wildly unlikely AFM reading as an obvious indication that something has gone awry, and then revert to a "safe" operating mode where it behaves as though it were designed before the advent of air flow meters.

But i could easily be wrong about your particular truck. Whether or not a 3FE will run with it disconnected is a sketchy question according to google.

 

[Timpanogos Slim]

http://www.harborfreight.com/general-merch/electrical/7-function-multimeter-98025.html

$4 for a cen-tech digital multimeter.

The backlight - if it even has one - will actually make the display harder to read when you switch it on. The probe wires have no strain relief on the probe end so you should wrap the end of the handle and the wire where it comes out there tightly with tape. You should either treat it gently or as a disposable item.

But it SHOULD WORK. I built many circuits using one just like it, except yellow.

If you ever decide to be slightly less cheap about a digital multimeter, my advice is to look for a used Wavetek/Meterman on ebay. 100% as good as Fluke at a fraction of the cost. Or buy a Fluke 17B, which isn't really a Fluke - it's a meter made for Fluke by Extech during a brief experiment in outsourcing. The internal build quality far exceeds the average extech. You will notice that the 17B is only available in asia. It is also identical to Craftsman model 81437, or would be if you added one more button. And some people do add it.

Oh, and buying new probes for a used meter should be considered a potential necessity. This military surplus set is excellent:

http://www.ebay.com/itm/NEW-Univers...411?pt=LH_DefaultDomain_0&hash=item2c6889483b

Dunno the seller. I just have a set just like it, and they are somewhat popular in the DIY set. Lots of 'em out there. Will withstand a nuclear bomb, etc. Might have to trim back the handle on the banana plugs for some meters.

 

[jonheld]

Do you know if the engine will run with AFM disconnected?

The AFM flap fires the secondary coil in the fuel pump relay (circuit opening relay). So without the AFM connected, the motor will fire then die as soon as you release the key from the START position.

If the CEL wasn't coming on with the AFM connected and does without the AFM connected, then you have a faulty AFM. A good AFM will have zero effect on the CEL. So assuming the AFM has been replaced, at this point the EFI circuit is functional and you should have spark and fuel delivery.

However we haven't had this motor running yet, so we don't know what other surprises await.

 

[jonheld]

If you ever decide to be slightly less cheap about a digital multimeter, my advice is to look for a used Wavetek/Meterman on ebay. 100% as good as Fluke at a fraction of the cost. Or buy a Fluke 17B, which isn't really a Fluke - it's a meter made for Fluke by Extech during a brief experiment in outsourcing. The internal build quality far exceeds the average extech. You will notice that the 17B is only available in asia. It is also identical to Craftsman model 81437, or would be if you added one more button. And some people do add it.

Or you could pick up a used Fluke 8060A for under $100 off of Ebay. These are the meters I grew up with. The first one I bought new is now over 30 years old and still as good as the day I took it out of the box. I have 3 of these meters now. Absolutely indestructible and highly accurate. Fluke will still service and calibrate them for a nominal fee.

 

[jcarter]

What else?

"However we haven't had this motor running yet, so we don't know what other surprises await."

Jon, you're killing me! Just kidding. I appreciate your support on this.

I'm sourcing a couple of AFM's right now. I'm suspicious about the part number since mine is a 8/92 and it seems Toyota put some unique, 4-month production parts in it. I have to be careful on EVERYTHING! I know water pump & pistons are different (90-7/92 & 8/92+).

In the meantime, I'm going to list parts & get a $ value on the project to update my write-up on the project ("Bad #2 Piston, Now What").

Electrically speaking, I'd assume anybody foolish enough to do such a project is going to run into electrical problems since 20 year old connectors get brittle as does wire.

Thanks for your help. I'll be back, hopefully with good news & not more issues & diagnostic work to do.

Joe

 

[Timpanogos Slim]

Or you could pick up a used Fluke 8060A for under $100 off of Ebay. These are the meters I grew up with. The first one I bought new is now over 30 years old and still as good as the day I took it out of the box. I have 3 of these meters now. Absolutely indestructible and highly accurate. Fluke will still service and calibrate them for a nominal fee.

Yeah, and used Waveteks sell for less than $50, and they offer similar services.

I've got nothing against Fluke - it's just that my wallet likes Wavetek/Meterman better.

 

[jonheld]

I'm suspicious about the part number since mine is a 8/92 and it seems Toyota put some unique, 4-month production parts in it.

AFM part number: 22250-61010
It shows production dates 01/90-08/92.

 

[jonheld]

Same part number for an FJ62. Production dates 8/87-1/90.

So your date range is from 8/87-8/92, or any 3FE motor.

 

[SiRaDuDe]

Well, the OP stated that he checked for SPARK and I assume he knows how to do this correctly, in that case...

I really don't know if a faulty AFM will prevent a spark from being delivered... I have no experience on a 3FE.

But... we might still have a spark issue which will need to be addressed via the previously provided links and diagnostics steps.

But, let's cross our fingers and hope this AFM issue it's all that's needed to solve your problem.

Any updates?

 

[jcarter]

Patiently waiting

Got a used AFM on the way, left this morning, AZ to MO, hopefully tomorrow, maybe Friday.

Checked with Cdan, these things are CRAZY MONEY! Why isn't there a post on FAQ with a picture that says DON'T UNSCREW THIS!!!!!

The guy I'm buying it from did the same thing I did during a tune-up. This is very irritating.

Ignition wise, I think I'm going to be fine. Why would a coil be bad? I didn't drop anything. All wires have been connected and accounted for. . .

Only issue I may have is the distributor, which is just bad luck. I didn't WANT to take it out, I HAD to take it out. While I was there, I decided to replace my oil pump. It had a burr on the female it sticks into. So, I had to take out the distributor to pound the old oil pump out.

So basically, I have an ignition issue because of my AFM ignorance and possibly burr on my oil pump holder. Everyday I got to listen to her "drive me, drive me", but NOOOO.

FRUSTRATED IN ST. LOUIS!

Joe