3FE - No CEL and no +12V @ B+ (1 Viewer)

[jonheld]

The ECU would have zero effect on compression and the fact that you say it "sounds" different when you crank it bothers me.
I have asked you this question 3 times now: Is the distributor rotor turning when you crank the engine?

 

[Maleficio]

From what I've gathered from his description he's got zero volts hitting his coil from the ECU, thus no spark. Is this correct?

 

[BSnBS747]

Yes, the dist and rotor turns, as stated in one of my last posts. I got off work a little early today so I am going to see how easy the motor will turn with a wrench. That sound bothers me too. Follow up shortly.

K

 

[BSnBS747]

OK that's messed up. Since I don't have a freakishly large crankshaft bolt socket, I used the flywheel and a small pry bar. I could honestly turn it by using it like a steering wheel if it wasn't attached to the trans. The motor turns that easy with the plugs in. Maybe its just a low compression motor, 8.xxx to 1. I'm used to my 18 to 1 diesel so......I'm gonna go out on a limb and say I have no compression. Why? I have no clue.

K

 

[jonheld]

From what I've gathered from his description he's got zero volts hitting his coil from the ECU, thus no spark. Is this correct?

B+ for the coil/igniter combo comes from the ignition switch circuit, not the ECU.
The pick up coils in the distributor create pulses that are fed to the ECU. The ECU then re-times the pulses according to its mapping and sends them to the igniter which in turn develops the pulses that are fed to the primary of the ignition coil.
This is why I wanted to know if the rotor was turning. It means that the crank is driving the cam, the oil pump is pumping, and the distributor should be developing the correct pulses to the ECU to create spark.
This is assuming things are connected correctly, which we haven't proven yet. However, if you have no compression, none of the electronics really matter much. I would focus on the mechanicals first, then worry about the rest.

 

[Maleficio]

B+ for the coil/igniter combo comes from the ignition switch circuit, not the ECU.
The pick up coils in the distributor create pulses that are fed to the ECU. The ECU then re-times the pulses according to its mapping and sends them to the igniter which in turn develops the pulses that are fed to the primary of the ignition coil.
This is why I wanted to know if the rotor was turning. It means that the crank is driving the cam, the oil pump is pumping, and the distributor should be developing the correct pulses to the ECU to create spark.
This is assuming things are connected correctly, which we haven't proven yet. However, if you have no compression, none of the electronics really matter much. I would focus on the mechanicals first, then worry about the rest.

Outstanding explanation!

 

[BSnBS747]

When the head gasket blew, I rented a uhaul car hauler and towed it back to my house. I then fired it up, drove it off the trailer and backed it into the driveway and shut it off. It cranked and ran fine, other than the oil and coolant mixing. I then proceeded to remove the head and other necessary parts to replace the head gasket. I had the head checked for straightness, cleaned, rebuilt, and milled .030. Once I received all of the necessary gaskets and parts, I finished the job. So...correct me if I'm wrong, but if I had compression before I removed the head, then I should have compression after the reinstallation of the head???? Rings and bottom end should be fine (or adequate for 265k miles) and the trouble may lie in the head rebuild??? It seems to turn like it has no spark plugs installed. The only thing that changed was the head. Attached is a couple pics of the rebuilt head.....anything out of the ordinary stick out???

K

 

[Maleficio]

I guess you should go ahead and check compression then. Get it out of the way, and give us some real data!!

 

[jonheld]

When the head gasket blew,

What was the original cause of headgasket failure?

 

[BSnBS747]

I think it was a problem that the PO was battling. Pretty much everything that held a fluid leaked. The radiator had a small seep at a few areas around the tank and had signs of being resoldered. I bought it around xmas, and never drove it much due to trying to catch up on some PM for it. Come spring on a project in Texas, it began to get warm one day while in traffic. So, I replaced the fan clutch and took the radiator to a shop to get cleaned and rebuilt. Come to find out that the radiator tanks were swelled up and beyond repair, so I installed a new radiator. Few months later while on a long highway trip to a football game with the family, I look down and the needle is around the 3/4 mark on the gauge and then that bypass hose (the one I told myself looked worn out, but didn't replace) blew. Pulled to the side of the interstate and had my dad tow strap me the last couple miles to their RV. That's when we put it on the uhaul and towed it back to my house after the game. I pulled the dipstick and it was chocolate milk. Pulled the head the next week and here is what I found. To me, it looks like it has been slowly leaking for a while and then it couldn't hold the pressure with the new radiator.

K

 

[BSnBS747]

Well, made a little progress this morning, fiddled around with a few things and wanted to see if my zero compression was due to the motor or the head. So, I pulled the plugs and poured a little bit of oil down into the cylinders (actually did it last night so that it would have time to seep down around the rings) and she turned over sort of like normal, little sticky tho. I failed to mention that she has probably sat 4 or 5 months while I was gathering parts and machine time. Im hoping that the rings were just really dry. Well, long story short, she fired and ran for about 10 seconds or so, little smoky and sounds like the timing could use a little attention. Kinda runs like a carby that's been sitting for a while, old gas and what not, spits and sputters. Apparently, my PO walmart battery isn't the strongest anymore, so Im hoping that the diehard platinum 65 that I have for my diesel will fit and continue trying to "blow the gunk out" and get the proper timing set. Will report back later with an update. Thanks for all of the help you guys, she wants to run, just needs a little more lovin.

K

 

[BSnBS747]

Well, she runs now. Kind of like a warmed over turd. But she runs. Takes a good bit of cranking then you have to feather it pretty good, but, she runs. Smokes like a chimney too. Smells like its burning oil now. Idles around 750-800, little rough, I'm sure timing is a tad off, little bit of engine shakes. Oil pressure is a needle thickness or two higher than the first mark on the gauge (not the zero mark), slightly higher than before the gasket repair. The oil pickup screen had some trash slightly blocking it when I pulled the pan. So what's next, adjust timing , think the excessive smoke will clear up, or do you think I'm looking at a bottom end rebuild? Maybe a 2fe? Ive got an old 350/700r4 waiting at home but i havent finished my part shopping yet. I wanted to run the 3fe as long as i could, maybe play around with it or even turbo it. Man I wish I had a place where I could pull it and do it all at once. I've been getting the stink eye from my landlord every time I work on it. Also, I probably just killed all the mosquitoes in the entire rv park. Thanks guys,

K

 

[jdayment]

Get a timing light make sure your timing is good the rough running might be due to the ecu relearning as well

 

[BSnBS747]

Engine smoothed out some when I turned the dist a bit. Ran out of adjustment so I think it maybe a tooth or so off. i need to check the timing better, dont have my light here. Still worried about the smoke though, not exactly sure if it is oil or fuel. Kind of smells like fuel or after you pour a bottle of seafoam down the intake.....is the ecu running it rich to relearn or something? It doesn't smoke much at idle, but starts when you throttle up. I am happy that she runs again, just need to get the old girl dialed in.

K

 

[jonheld]

Did you adjust the valves to spec?
She shouldn't smoke at all.

 

[jonheld]

You should also pull the 15amp EFI fuse for a while and let the ECU reset. This will clear any stored codes and allow it to relearn the sensors. I do this anytime I do basic engine work.
You need to go through all of the mechanical adjustments first. Then dial in the electronics

 

[BSnBS747]

I left the valves/rockers a little sloppy just to make sure that the valves were closing all the way to rule out the low compression due to an open valve. When I get a chance this week, I am going to pull it apart and set the valves to spec and check/adjust the timing. I will pull the efi fuse once I am done so it will reset. It fires up with less effort now, I am hoping that some of the spit and sputtering problem is from old gas. There is about a half a tank in it from September or so.......The main fix came from the post that mentioned the EB1 connector. I had to look that connector up, after that, I had a cel and power where it should be. That connector got lumped in with the other wiring for the smog junk and zip tied out of the way of the belts. Thank you everyone for all of your help. I will report back once I get a chance to look at it again.

K

 

[BSnBS747]

OK, bump for an update. She is running fairly well other than I now have a coolant drip coming from under the water pump pulley, haven't had any time to investigate further at the moment. It may be time for a new water pump anyway. Not sure if its the original or not but with 270k on the clock and the overheating issue I had, I think its time. The smoke has cleared up, the bit of oil that I used to lube the cylinders got trapped in the cats and would start to burn off when the cats got warm. And due to the water drip, I never let it get up to temp long enough to burn it all off. So, I moved some of the need to do exhaust work up the list and cut the "whatever we have on the shelf" cats off and just deleted them for the time being. The PO welded 2.5" cats in place of the stock ones and then just welded the gap around the pipe, guess they forgot to weld the top of the pipe too, huge leaks. Plus, they welded it directly to the y pip flange. Bye bye to unbolting it. Then later I'll get rid of the coat hanger hung butched up exhaust system that the PO did for something a little more professional looking. Coat hangers are good for a trail or on the side of the road fix, but shouldn't be used as a permanent mounting system. Exhaust hangers are like 5 bucks.
Also, anybody know of a good way to flush rust and gunk out of the engine block? CLR?Apparently the the PO had a few coolant leaks (radiator and seeping head gasket) and used regular tap water to top the level off. Which left some holes and pipes a little on the clogged/rusty side.

Thanks to everyone for all of the help.

Keith

 

[LhPickle]

New OEM fusible links are $12. Why give this a second thought?

Try unplugging the AFM connection. If the 2 phillips screws on the AFM housing were removed and the internal circuit board was moved, then there is likely a fractured wire. This can prevent the ECU from entering the "ready" state and energizing the EFI relay.

I would make sure that each pin of the EFI relay socket is good. Here is a diagram of the pinout along with the OEM wire colors. Make sure you're getting a good ground on pin 1 (brn). The pin 2 (red/yel)+12 comes from the EFI fuse and should always be present. Pin 3 (red) is the logic signal from the ECU that energizes the relay coil and it should read around +12 or so with the key in the ON position.

You will not get +12 at the diagnostic port until the EFI relay is closed.

View attachment 1411291

@jonheld do you have similar diagram for the relays in the driver's side kick panel?

I am having trouble getting my rig to start. My situation is different, that OP. All of what I am saying is before I found your diagnostic procedure this afternoon at work, which I will go over when I get home.

My family and I were running some easy trails near our house, when we stopped to look at a moose and the engine shut off. I let it sit for a minute before I tried to restart it (I had had no problems like this before), so after I let it sit while my kids watched the moose I turned the key and it fired right up. About 20 min down the trail (we were 1.5 hours into the trail) we ran into a 25' section of 8" deep mud that we drove through (mud everywhere, but not stuck) and went on our way home with no issues.

When I got home I parked the 91' in the driveway to spray it down and get the mud off the body, knuckles and undercarriage. When I went to start it 30 min later it would turn over, but not start, it was late so I pushed it into the garage and figured I would deal with it the next day.

The next day I went out to look at it, figuring that somehow water must have gotten into the distributor cap and was stealing spark, but it was dry inside. It did have all what appeared to be the original rotor, wires and plugs, so I figured I would just replace those. So I put in a new rotor, cap, plugs and wires. Still it would not start, so I sprayed starter fluid in the air box and it acted like it wanted to start, so I knew that I had spark.

My next thought was that I am not getting fuel to the motor. I had replaced the fuel filter last summer, so I figured that was good so I went ahead and replaced my fuel pump, figuring it was likely original and ready for a change out anyway. I changed out the Fuel pump and Main EFI relay under the hood. So after I had it all put back together I tried to start it and it would still not start.

So today at work during some down time I hopped on IH8Mud and did some searching and found this thread and a few others and saw your diagnostic procedure talking about no CEL so I had my wife go and turn the key to on and the CEL is not illuminated.

Here is what I have done since this started:
1) New rotator
2) New distributor cap
3) New spark plug wires
4) New spark plugs
I know I now have spark

5) New fuel pump
6) Last year I replaced the fusible link and main battery ground.
7) I verified that I have +12v at the fuse/relay box in engine compartment.
8) New EFI main relay (engine compartment box).

When I get home tonight I will check the following:
1) B+
2) AFM connector
3) ???

Thanks in advance for any advice.

Will