howdy, having an idle stumble on '93 fzj80

[BNC]

HI folks, nice forum

After taking Moby ('93 FZJ80, 154k, stock) to the dealer for the 150k service I've been having a stumble at idle.

I start up fine, but shifting in to R or D to get going makes the rpm drop, then it just starts choking with the rpm dipping to nearly nothing then jumping back up to idle; if I don't get on the gas it dies.

This happens the worst at cold startup, but does it nearly any time I let of the gas and let it go to idle. It is better after a long highway drive, but just when I think it is fine it will die on me.

I thought it might be some of the fuel system cleaner getting gunk out of the engine, but it has been 5k at only marginal improvement.

Any thoughts?

BTW, once I get above idle it runs as smooth as always. Good thing these trucks are built to last forever, because I have no intentions of getting rid of mine, at 154k it is barely middle aged

Thanks
Ben

 

[IdahoDoug]

I'll betcha a Starbuck's double shot extra hot Grande Mocha Valencia that they cracked the pleated section of the large black rubber air intake tube connecting the air cleaner to the throttle body. Remove the wire clamp from the throttle body end and gently wiggle it to get it off after you've removed the air cleaner end. DO NOT pull up on it to change an air filter or - crack. You have the classic symptom.

DougM

 

[BNC]

I owe you a latte Doug

There is a noticable crack (must be if I, who knows no Cruiser tech, can find it that easily) between the first and second "rib" on that large hose (counting from throttle body end).

I'll take it in next weekend, hopefully they won't give me any trouble, it was done in Aug. so it has been a while. (I thought it was a fuel problem so I waited to see if it would clear itself out)

Thanks again

 

[CDN_Cruiser]

BNC:

You may as well contact CDan now and have him ship you a new hose. As sad as it is, I really doubt that the dealer will cover the damage 7+ months after the fact. Given that this is the kind of thing that you notice right off the bat, they will think that it's unusual that you only just noticed the problem.

In any case good luck!

Cheers, Hugh

 

[BNC]

Is there anything tricky about replacing it yourself? It looks simple enough, but I'd hate to crack the new one....

 

[Rich]

In any case, I don't really think the cracking is so much the tech's fault. The material the intake hose is made from does not standup to the environment in the engine compartment.

It is reasonable to expect to be able to pop open the air filter housing without expecting the rubber intake to break. Unfortunately, that is not the case.

Might be worthwhile to explore aftermarket tubing that could be used to fabricate a more durable intake tube.

Now where the tech did fall short is returning to you a vehicle that idled poorly.

 

[Rich]

Flex it as little as possible. I would expect that the new one will be much more flexible than the old one, for now. After it bakes for a number of years in the engine compartment, if it is the same composition as the old one, then it will lose it's compliancy and become more brittle.

 

[robbie]

Even when new the hose was not designed to be just lifted up to change the air filter. But I do agree that the material could be designed to hold up to the heat of the exhaust below it. The hose needs to be removed from the throttle body before you lift it to replace the air filter. those filters are really tall. It does not take that long to loosen the hose clamp on the throttle body and remove the hose and upper air cleaner assembly. later robbie

 

[BNC]

Can someone point me towards this CDan fellow (is he Cdaniel or someone else, website?), or a place online where I can order the part? Part number would also be helpful.

Thanks again guys.

 

[IdahoDoug]

In the interim, just a couple wraps of duct tape around the ribs will instantly cure the idle. Best seal possible is your goal, but even a casual wrap will do it. Cdan - PM him and find him on the "member's list" somewhere here at the top of the page. Great service/price/advice.

DougM

 

[landtank]

CDan is short for CruiserDan, one our members here and a great source for OEM parts at a discount price.

 

[jaysdead40]

Sorry for jumping in here, but how does a leak in the intake hose affect idle when all the sensing is done down stream from it. I can see dirt and crap reaching the engine but how does it affect idle.

Has anyone tried an aluminum tube and flexible connectors rather than the stock piece.

Jay

 

[cruiserdan]

The crack develops between the air metering device and the throttle body. The net result is the engine is running leaner than the fuel management thinks it is, not a good thing.


D-

 

[jaysdead40]

Right as always CDan. That's what I get for opening my mouth before I open the hood.

Jay

 

[e9999]

just cover the crack with good tape. You'll probably be fine for a while.


Ain't this great, though? Free and accurate diagnostic in 1 hour. Kudos to Doug. Sure beats going to the dealer... Ben, you really oughta get a star now to rebalance your Karma!

 

[cruiserdan]

Did Mr, "Get the exact tow hook bolts" just tell somebody to tape up the air intake?????

 

[BNC]

I must say this place is great, Doug nailed it almost as fast as I typed it

I'm going to Duct the heck out of it this weekend (school killing me right now), and then look for some hoses.

A project I'm working just so happens to have me researching types of hose, so I should be able to find something that will work. And of course you guys will get a write up if I find something good.

If not, I'll be contacting the famous cruiserdan for some hose

 

[BNC]

I found some marine hose here that looks pretty good.

Does anyone know what the maximum temp the engine compartment is likely to reach? The hose can handle up to 200F

Also, would anyone happen to know the inside diameter of the hose that I'm replacing off the top of their head?

thanks again

 

[e9999]

Did Mr, "Get the exact tow hook bolts" just tell somebody to tape up the air intake?????







%$#@^

here, I got better:

just use a dryer exhaust pipe for it! It's about the right size, just duct tape the ends now...!!! And if you use the aluminium one, it'll Bling!

 

[IdahoDoug]

"Did Mr, "Get the exact tow hook bolts" just tell somebody to tape up the air intake?????"

Been wondering where you were. I've been slandering you in Chat, 80, and that gay quilting website you mentioned once, with no counter abuse. Good to know you have a pulse still....

DougM