Help, rough idle after headgasket job.

[Fj80oregon]

I only ask because the connectors are notorious for being extremely brittle and breaking when you remove them and you could have a bad connection at one. I did a HG in the truck and fighting your same symptoms and it ended up being #5 injector plug was jacked up but it looked good from the outside. Just trying to think of easy things for you to check.

 

[89autoworks]

I only ask because the connectors are notorious for being extremely brittle and breaking when you remove them and you could have a bad connection at one. I did a HG in the truck and fighting your same symptoms and it ended up being #5 injector plug was jacked up but it looked good from the outside. Just trying to think of easy things for you to check.

I’ll check it out. I had replaced 2 connectors with pigtails. Soldered and heat shrunk. I’ll check it out for sure

 

[CharlieS]

You're a pro, I'm not. I crimp those connections, not solder them. No doubt your approach works. Are all of the injectors ticking?

 

[89autoworks]

how sensitive are these old mass airflow meters, i did remember that the whole intake assembly took a small drop to concrete when i disassembled the motor? I'm talking 2 feet or less, no damage to the airbox whatsoever

 

[89autoworks]

okay, so here's what i have found out, i couldn't stand the unknown. i tore the valve cover off to check timing again, with all dots PERFECTLY lined up on the cams, the crank pulley is reading around 7 degrees. with the crank pulley on 0, the cams barely come out of perfectly flat, which is nearly impossible to see, other the the "two dots" portion of the cams are just barely below the valve cover mounting service by about 1/32nd of an inch., so clearly that is not perfectly happy, and I'm not sure how to make it perfectly happy.

secondly the auto zone dizzy rotor, i realized that there is play in it, and with little to no pressure you can change the clock by about 10 degrees. yes this is the brand new one, i checked the old one, it too also has a large amount of room for error, but about half of the new one. thinking i better get an oem.

but as far as the cam timing being ever so slightly off, does any one have any big brain ideas on how to make it perfect again??

 

[89autoworks]

No, what I’m saying is the timing marks on the chain take 17 revolutions to line back up with the sprocket timing mark. If you had the dots on the cams lined up and timing dot on the chain sprocket and harmonic balancer all lined up at 0 then you should be good there.

Okay, so i jumped the chain 1 tooth, made everything perfect, when i ran it, it ran noticeably better, but not perfect. after pulling the dizzy again, i checked the air gaps, and both where under .006, and factory spec being .008-.016, id imagine this would play a decent roll in my poor spark condition.

 

[Fj80oregon]

Okay, so i jumped the chain 1 tooth, made everything perfect, when i ran it, it ran noticeably better, but not perfect. after pulling the dizzy again, i checked the air gaps, and both where under .006, and factory spec being .008-.016, id imagine this would play a decent roll in my poor spark condition.

What do you mean jumped the chain 1 tooth? Your dark mark on the Chain should correspond with the dot on the timing gear on the cam and the crank woodruff keys.

 

[flintknapper]

Sounds like your cam alignment was OK.

I would revisit the distributor. Bring the engine back around to TDC (on compression stroke) on the #1 cylinder. Pluck the dizzy and start over.

Some things to note:

Alignment marks on distributor must be lined up.

Before you start to insert the dizzy into the bore in the head, you will need to 'retard' the rotor position about as illustrated below. The reason for this is that the gears are helical cut and the rotor will 'rotate' clockwise as the gears mesh/seat.

It is important that you start the dizzy insertion such that the slot in the distributor housing (for the hold down bolt) is aligned about in its center with the bolt hole in the head. Then do NOT twist the dizzy in any way to get to go in. Just push it straight in.

If everything goes right the rotor will rotate to roughly the left-hand edge of the distributor electrical connector boss (see pic #3 above).

This should have the timing close enough to 'start' the engine. Then advance it with a timing light per FSM.

IF the rotor does NOT fall into the areas shown (one direction or the other) you can assume you are off a tooth and need to try again. Otherwise you'll end up with the dizzy fully advanced (most often), engine running poorly and no room for any more adjustments.

Reinserting the distributor is probably the #1 thing folks have trouble with.

 

[89autoworks]

Sounds like your cam alignment was OK.

I would revisit the distributor. Bring the engine back around to TDC (on compression stroke) on the #1 cylinder. Pluck the dizzy and start over.

Some things to note:

Alignment marks on distributor must be lined up.

View attachment 3669398

Before you start to insert the dizzy into the bore in the head, you will need to 'retard' the rotor position about as illustrated below. The reason for this is that the gears are helical cut and the rotor will 'rotate' clockwise as the gears mesh/seat.
View attachment 3669402
View attachment 3669403

It is important that you start the dizzy insertion such that the slot in the distributor housing (for the hold down bolt) is aligned about in its center with the bolt hole in the head. Then do NOT twist the dizzy in any way to get to go in. Just push it straight in.

View attachment 3669404
If everything goes right the rotor will rotate to roughly the left-hand edge of the distributor electrical connector boss (see pic #3 above).

This should have the timing close enough to 'start' the engine. Then advance it with a timing light per FSM.

IF the rotor does NOT fall into the areas shown (one direction or the other) you can assume you are off a tooth and need to try again. Otherwise you'll end up with the dizzy fully advanced (most often), engine running poorly and no room for any more adjustments.

Reinserting the distributor is probably the #1 thing folks have trouble with.

So i had moved the chain 1 tooth to line all my marks up to exactly, ran way better at that point. with the timing light on, i was still showing below 0btdc. i lined everything back up to cyl 1 tic, moved the dizzy 1 tooth forward, runs good enough to move down the road under its own power, but still is very cranky, and you have to have it set to like 15 degrees on the crank pulley with the timing light to get even remotely decent running. i also saw that all the air gaps for the pickups in the dizzy where way under spec at .006" , the fsm says to replace the whole dizzy when this happens, i chose to attempt to open up the gap by loosening the screws for the pickups and using a feeler gauge to get them set back in spec. I'm just wondering if it even possible the dizzy could be a culprit in this situation before i dump 500 bucks on a new one.

 

[89autoworks]

What do you mean jumped the chain 1 tooth? Your dark mark on the Chain should correspond with the dot on the timing gear on the cam and the crank woodruff keys.

View attachment 3669338

i never have fully pulled the chain, i had zip tied it to the cam gear, but that doesn't mean the crank gear couldn't go back a tooth. i saw another thread with a guy that had the same issue, they told him to back it up a tooth on the cam gear to make all the marks line up perfectly.

 

[89autoworks]

now i finally have a CEL for code #12, which is basically telling me the distributor is junk. so finally a smoking gun.

 

[flintknapper]

now i finally have a CEL for code #12, which is basically telling me the distributor is junk. so finally a smoking gun.

Yeah, bad or failing Pickup. Until replaced....all else will be a Wild Goose chase.

 

[89autoworks]

Yeah, bad or failing Pickup. Until replaced....all else will be a Wild Goose chase.

I ordered a freshie. Will have it tomorrow am, then we will know more.

 

[BILT4ME]

Another thought:

Is the harmonic balancer compromised? It's possible the timing mark on the outside ring has rotated compared to the inner hub if the rubber has failed, but still tight enough to operate.

 

[89autoworks]

It’s possible, but I also use a screwdriver to make sure the piston is all the way at the top of its stroke. If the dizzy doesn’t fix it, that’s certainly the next place I am looking, and by looking I mean just replacing

 

[89autoworks]

so, new dizzy, runs way way better, but still seems like a major misfire or cylinders not getting a proper combustion. timing mark on plugs 1,3,4,5 was all the way at the base of the electrode at 7 degrees btdc with the terminals jumped. cylinders 2 and 6 are still pretty black. 175-180 psi across all 6 cylinders. seems to me like the thing is pulling timing or something, runs and starts so much better with the new dizzy, but clearly we still are fighting some other issue.

 

[89autoworks]

somebody for the love of god HELP ME!!!!!! i ended up throwing codes 12,24,31. i ordered a reman OEM VAF off a seller on eBay (one stop and shop), they had good reviews and 200$ for a reman poem part seemed to be a great deal, or better then a new china unit. i went ahead and installed the thing this am, now my landcruiser will not even idle at all. idles super low, eventually dies out. what the hell am i doing wrong here, this is not the toyota experience i was expecting at all. if there is anyone that is actually skilled on these early 80 series, i will pay for your time for a phone call to help me figure this out. my huge predicament is i move on 7-18 and this landcruiser has to be loaded and shipped 7-17, and when we arrive, this is the only vehicle we will have for transportation for my family of 6! if some one wants to make some money and help me figure this out, i am all ears and will absolutely compensate you for your time. PLEEEEEAASSEE

 

[TheBussman]

put the original one back in. does it run better or worse when propane is added to in the intake? How many inches of manifold vacuum? Did you smoke test the intake for leaks? Put a piece of paper on the exhaust pipe while it's running and missing will it suck the paper in? Did you check the harmonic balancer?

 

[89autoworks]

put the original one back in. does it run better or worse when propane is added to in the intake? How many inches of manifold vacuum? Did you smoke test the intake for leaks? Put a piece of paper on the exhaust pipe while it's running and missing will it suck the paper in? Did you check the harmonic balancer?

How exactly do I tell if the harmonic balancer is junk? And the propane, what exactly is that going to tell us?

 

[TheBussman]

How exactly do I tell if the harmonic balancer is junk? And the propane, what exactly is that going to tell us?

you can see rubber cranking around the balancer, but i just noticed that you said you already checked TDC mark against the piston so don't worry about that. Adding propane can help you determine if it's running too rich or too lean. First add the propane to a a car that's running fine and see how it should react and then try it on the problem car. If all that checks out i would unplug the ECU and go pin to pin to make sure all the sensor readings are good, grounds and powers are good, you said the wiring harness was in bad shape, I know you fixed alot of issues already but there may be another issue you didn't see. A good OBD 1 scan tool will tell you a little bit of data also.