Diagnosing a problem – Engine shaking & pulsating when in reverse and drive – making weird sounds… Plus Q about OBDI code checking…

mrq

mrq

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Hi, all!

So OF COURSE after I spend thousands on a rear bumper + install my rig starts to act up! (I have such sh*t luck in life – I really do…)

ANYWAYS!

My engine is running strangely. About 2 weeks I had the check engine light come on twice for about 1-2mins then it went off. Since then it hasn’t come back on.

Today I got in my rig to leave and when I started it up (cold start) it started like normal – rev’d up to about 1500… Then it suddenly dropped – the RPM’s first and right after my car felt like it “dropped” downwards, almost. I put it in reverse and then my engine started shaking and pulsating/throbbing. I backed down my driveway and into the street then put ‘er in drive. It did the same thing while in drive – shook, pulsated, and felt like the front end of my car was throbbing. I drove around the block and it continued… So I pulled back in my garage and shut my rig off and ended up taking my other car because I didn’t feel comfortable driving my 80.

Anyone have a clue what these occurrences may be caused by? I know for a fact that my air filter is dirty and needs replaced – last time I had my LC mechanic do work on my rig he said that next time I bring it in I need to have that done.
But I wasn’t sure if that could even be a cause of the symptoms my engine is having? Maybe if the engine isn’t getting enough air?

I was also suspecting maybe the throttle body or fuel filter?


Any suggestions or advice as to where to look first would be appreciated!

Also: I went to check the codes on my rig (using paperclip method) and I got no codes – the check engine light stayed turned on the entire time while in accessory mode – no blinks. Idk if OBDI 80’s store codes or not?

Hoping it’s not a big issue or expensive repair. Like I said I just bought a bumper and had it installed – which cost a ton. So I’m kinda in a tough place because I used my set-aside 80 budget all up on the bumper and install.

Thanks much!

– M
 
mrq

mrq

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FYI: I’m mechanically illiterate. I’m SLOWLY learning to do simple things. I’m not handy at all so I don’t do work on my own rig. The only thing I do myself is change the oil. I hope to change that, but in the meantime I have a great LC mechanic who’s been working on my rig since I got it.

I did, though, take off the running boards and installed the front mudflaps myself the other day… So that’s, something? 🤣
 
Halfpint

Halfpint

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My guess is a vacuum leak or a crack in the intake hose...when in gear, it flexes it just enough to create the leak.
 
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mrq

mrq

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My guess is a vacuum leak or a crack in the intake hose...when in gear, it flexes it just enough to create the leak.
Do you think replacing these items would be a good place to start?

Screen Shot 2021 10 28 at 103036 PM
 
mrq

mrq

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The first rule of ih8mud is to diagnose the problem, not throw parts at her. That being said, all those items are relatively easy to replace. The fuel filter is tricky without the right extensions.

Makes sense... Right! I just figured that replacing these items could likely solve the issue. And I assumed that these items weren't too difficult to replace. And a plus would be getting to replace the old (and likely original) parts. Here's some pictures. I visually inspected the air intake hose and didn't see any cracks or breakage...

IMG 9597


IMG 9595
IMG 9594
IMG 9593
 
LINUS

LINUS

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Do you think replacing these items would be a good place to start?

View attachment 2824155
By virtue of age, a new intake pipe would be a good buy. -But for diagnosis purposes, you could Gorrilla tape any leaks you find - the bellows over the valve cover & underside are where they like to crack.

If you don’t know the history or have never changed the fuel filter, smart money starts there.

I’d leave the air filter for last - even a dirty one the air is metered after it in the AFM - so really dump the tuna can, change the fuel filter, really pull & examine the intake pipe as leaks there are unmetered air / screws the A-F ratio - but yeah, yours is old but can be made functional until the wallet rebounds & esp w/ Holidays looming….

HTH
 
mrq

mrq

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By virtue of age, a new intake pipe would be a good buy. -But for diagnosis purposes, you could Gorrilla tape any leaks you find - the bellows over the valve cover & underside are where they like to crack.

If you don’t know the history or have never changed the fuel filter, smart money starts there.

I’d leave the air filter for last - even a dirty one the air is metered after it in the AFM - so really dump the tuna can, change the fuel filter, really pull & examine the intake pipe as leaks there are unmetered air / screws the A-F ratio - but yeah, yours is old but can be made functional until the wallet rebounds & esp w/ Holidays looming….

HTH
THANK YOU!
 
LINUS

LINUS

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I sorta messed saying it - but the last long sentence is the priority / order I’d do it in.

-Or while waiting for a fuel filter to show, check the intake tube & just make sure it‘s functionally sound.

A quick / easy intake tube test is to slightly shift it while idle - if you can really screw up the idle, go get the Gorrilla tape ;)

-Trying to spend your $$ as smart as possible, unless you want to just throw new parts until fixed - some do & I have on occasion.
Just not w/ the Holidays on us so soon.
 
mrq

mrq

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Well it wasn't the air filter... Replaced that and the problem still persists. So off to the shop she goes! My best guess is that it's a vacuum leak somewhere. The idea of trying to find the source of the leak is overwhelming – so I'm just going to have my LC guy look at it. I was thinking maybe it's a bad motor or trans mount?

Anyways... KEEP YOUR FINGERS CROSSED FOR ME THAT IT ISN'T SOMETHING $$$ TO FIX! 🤞
 
LINUS

LINUS

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Well it wasn't the air filter... Replaced that and the problem still persists. So off to the shop she goes! My best guess is that it's a vacuum leak somewhere. The idea of trying to find the source of the leak is overwhelming – so I'm just going to have my LC guy look at it. I was thinking maybe it's a bad motor or trans mount?

Anyways... KEEP YOUR FINGERS CROSSED FOR ME THAT IT ISN'T SOMETHING $$$ TO FIX! 🤞

That’s why I had the air filter last - long ago it was stated that the filter is near a lifetime filter in the USDM market - things like a K&N filter made for more work that the OE.

Gotta remember these rigs were built to run in Africa dust & Middle East powder-sand. And even then, dump the tuna can, pull & squirt compressed air from the inner baffles outward & call it good.
(unless you’re going to a forced intake, either style)

Like you say, it’s either vacuum lines (old too, and so easy to crack the tube at a nipple) - or the metered air / leaky intake tube.

Fuel filter would let you idle fine, but chug/sputter under heavy fuel draw say when you really get into the skinny pedal.

HTH
 
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mrq

mrq

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That’s why I had the air filter last - long ago it was stated that the filter is near a lifetime filter in the USDM market - things like a K&N filter made for more work that the OE.

Gotta remember these rigs were built to run in Africa dust & Middle East powder-sand. And even then, dump the tuna can, pull & squirt compressed air from the inner baffles outward & call it good.
(unless you’re going to a forced intake, either style)

Like you say, it’s either vacuum lines (old too, and so easy to crack the tube at a nipple) - or the metered air / leaky intake tube.

Fuel filter would let you idle fine, but chug/sputter under heavy fuel draw say when you really get into the skinny pedal.

HTH

CAUSE OF PROBLEM IDENTIFIED!

Took Bessie into my LC mechanic today and found out that it's a bad fuel injector. I believe he said it was fuel injector #4. So I'm having him replace it AND the other 5 fuel injectors + associated gaskets and all 6 connectors.

OF COURSE something had to go wrong w/ my rig literally a week and a half after I spend $3,500 on a rear bumper + install. (Murphy's law, amirite?)
This repair was NOT in my budget... But it's 'gotta be done, so I'm having to bite the bullet. My mechanic said that he'll get the results of my courtesy inspection on Monday AM – and also will give me adt'l quotes for other things they found. Unless there's something that's super urgent or deemed important to fix I'm going to have to put off any further repairs/maintenance until I save up some more money for the LC fund.

Man, I wish I had a cool Grandpa or Uncle that knew how to work on cars and could help/teach me! Me and my father are capable of repairing minor things, but most of the maintenance on my 80 I have done at my LC mechanic's shop. One, because I trust him and he really knows what he's doing – and two, because me and my Dad's skills are so limited. I know that 80's aren't the best choice of car to drive if you are unable to perform your own repairs/maintenance... But they're just so f-ing cool! I love mine so much – and I loved my Mom's 80 growing up and when I got to drive it when I first got my license.
 
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Nemesis1207

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Good to hear the problem is solved. I'd make sure you ask the mechanic for the old injectors. A new set of injectors is great, but I'd keep the old ones sealed on the shelf somewhere so you can get them rebuilt in the future if needed, especially if those are genuine ones and he's putting in aftermarket ones for you.
 
mrq

mrq

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Good to hear the problem is solved. I'd make sure you ask the mechanic for the old injectors. A new set of injectors is great, but I'd keep the old ones sealed on the shelf somewhere so you can get them rebuilt in the future if needed, especially if those are genuine ones and he's putting in aftermarket ones for you.
Thanks for the tip – I'll do that. I'm having him put in new OEM Toyota injectors. He recommended to me to "definitely go OEM".
 

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