Exploding sound inside the cab when I start the 60 (sometimes)

[Zack1978]

Hello,
I seem to have an ongoing problem with my 1987 fj60. It seems to make a poping or exploding sound when I start it. The sound seems to be emanating from the pass side under the glove box area(Inside cab). It seems to only do this when you restart the truck after sitting for about 45-60 min. It happened yesterday, I drove down the highway for about 30 miles then it sat for about 1hr, when I restarted it the exploding sound happened.
Someone told me that a VCV? valve is bad. So I went to Toyota and ordered what I thought was the VCV(If that is what it is called) and installed it. It does not help! The part I replaced was a plastic valve that is near the dist, and it clips onto the bottom of the air cleaner. And it has 3 or 4 hoses attached to it. Is that the part I should have replaced? This is making me nuts!!

Thanks,
Zack

 

[60wag]

The explosion is probably a gas/air mixture being set off by the distributor (in the distributor). The dist vent is supposed to pull fresh air from behind the glove box into the dist cap and then into the air cleaner. The VCV you replaced controls the vent operation. THe plumbing for the VCV tubes is a bit odd. Any chance its hooked up wrong? That might allow a backfire condition to pump some fueled mixture back into the dizzy. In some extreme cases, it blows the dizzy cap apart. Until you figure it out for sure, you could disconnect the tube bewteen the dizzy cap and the VCV and plug it.

 

[Zack1978]

Is the VCV valve the part I described??


Zack

 

[nuclearlemon]

when mine was doing that, it was one of the valves up by the front of the valve cover. i can get the part number when i get home.

 

[60wag]

Yes, the VCV is the thing you described

 

[chitown40]

The explosion is probably a gas/air mixture being set off by the distributor (in the distributor). The dist vent is supposed to pull fresh air from behind the glove box into the dist cap and then into the air cleaner.

I'm glad this was brought up, as I had no clue why there was a vacuum hose going from the firewall to the dizzy, especially when my vacuum diagram shows something completely different. This explains a lot and will definitely help when I put my mess all back together. Thanks.

 

[Godwin]

I have had under-cap distributor explosions occur with enough force that on two occasions the distrubutor cap actually had a piece blown from the side. The sound was loud enough that I checked under the hood, and the 2F ran just as well with a hole in the cap as without. But I did replace the cap as soon as possible.

 

[nuclearlemon]

ok, it was the vacu-valve...part number 90925-03058...cost about $45 a couple of years ago. haven't had a problem since.

 

[sj]

Would this allow for a burning smell in the cab. This happens to me every now and then. It hadn't happend in a few months so I thought it somehow fix itself. It did it agian just the other day. Maybe it is starting agian now that it is getting hotter.

Sometimes when I start it I will hear a popping sound, or pff sound, coming from below the glove box speaker area. If I lean over to the glove box I can sometimes smell something burning. I thought it was something wrong with the speaker.

I am going to look at this tomorrow.

Sean
1987 FJ60

 

[Pluton]

Caution

The explosion is probably a gas/air mixture being set off by the distributor (in the distributor). The dist vent is supposed to pull fresh air from behind the glove box into the dist cap and then into the air cleaner. The VCV you replaced controls the vent operation. THe plumbing for the VCV tubes is a bit odd. Any chance its hooked up wrong? That might allow a backfire condition to pump some fueled mixture back into the dizzy. In some extreme cases, it blows the dizzy cap apart. Until you figure it out for sure, you could disconnect the tube bewteen the dizzy cap and the VCV and plug it.

Don't leave your distributor w/o the suction+fresh air provded by this system too long 'cause the foul air inside the diz. can damage the signal generator("pickup coil"?) inside the diz...I don't know how long it takes w/o fresh air to do damage but I'd guess it's a matter of a few months. There should be suction (vacuum) from the vacu valve thru the hose to the port on the diz cap whenever the engine is running, including idle. Hope this helps.

 

[crawlin60]

Ditto here on those explosions. I was pretty sure it was a speaker pop, but the burning smell told me otherwise. In mine it's infrequent, but noticeable. I had no idea that it was related to gasoline fumes in the distributor. Thanks for sharing that one...

 

[Zack1978]

SJ,
Yes I also get the burning smell when the popping sound happens. I guess I have to order the part the Nuclemon told me about. I just don't want my dist cap to explode.

Zack

PS: any other tips as to how to fix this problem? Does anyone have a pic of the correct way the hoses are to be attached?

 

[sj]

I am going to bump this, last weekend I put a new cap, rotor, and plugs in and the popping sound is back.

Zack, did that part fix your problem? Does anybody know anything else that can fix the problem?

Sean

 

[SilentUnicorn]

why is there an explosive mixture under the cap?

 

[nuclearlemon]

the exploding sound is caused by a vsv (?) valve that's plugged. it's letting gas fumes flow back into the distributer. pull the little plastic valves one at a time...they work like check valves, so you should be able to blow through one way, but not the other.

they run about $60 at the dealer.

 

[Zack1978]

I guess we have to get what valve we are talking about straight? I orig replaced what I think was called a VCV valve (it clips on to the air cleaner, below it). I replaced that but it still did it afterwards a few times, so I don't think that solved my problem. However it has been a LONG time since my 60 has done it so I guess I forgot about it. As Murphy's law would have it, I am sure that it will start up again soon! What other valves should we look at replacing?


Zack

 

[nuclearlemon]

there's three or four of them, vsv, vcv and i don't know what the other two are called. iirc, mine ended up being the one up by the thermostat housing.

 

[ColoradoLC]

Wow, I am glad I caught this thread. My 86 is doing the same thing. Originally I thought it was the crappy stock passenger speaker too, but I replaced all of them in January and still had it happen. I will have to check this out.

Are there any internet friendly dealers that we can order this part from? I have had to swear off my local dealer as non-FJ60 friendly.

 

[weak-link]

look up "cruiserdan", I think he can help you out on Toyota parts.

 

[Kief]

Pic?