Chevy & GMC Vans

Long story short I'll jump right to the issue.

I have a 1999 Astro AWD Cargo that is my work vehicle and in need of some repair and I am at a loss as to sell it or fix it, mostly because I do not know what is wrong with it so I am hoping that someone can help out.

I had an issue with the rear end, which I'll post in the other forum topic for the cat.' But I went a couple of weeks with out starting it and went to start it up and it seemed like it was having a hard time getting gas. Thought well it has been close to three weeks so lets give it a little gas. So I pumped the gas a few times.

Then after a few more tries it started, but with a big BOOM! the muffler actually exploded. I am serious. I have never seen anything like that ever. Well anyhow so now I am noticing a gas smell. So I look at there is gas coming down the exhaust pipe somewhat streaming to where my muffler used to be.

I am not sure what this could be or even where to start looking. So I am looking for some guide from someone who knows a lot more about these then I do.


1999 Astro AWD Cargo
4.3 Vortec
176,000
summer 11' replaced lower intake gasket and almost all front end parts, and full tune up while doing lower intake gasket
no CAT

Sounds like it's flooding from a stuck open injector. I'd pull the injectors and have them profesionally cleaned and flow tested..

Also check your oil, if there is raw fuel dumping into a cylinder it's also going to drip past the rings into the oil. It will dilute the oil until it's like water (and explosive too).. Don't smoke around it, friend had this issue and was leaning over the motor with a cigarette hanging out of his mouth. It cought and blew one of the valve covers right off the motor. Gave him quite a cool new hair do too..

sounds like nothing easy, or for that matter. Good.


I am hoping after doing some research that maybe it is the fuel regulator, and hopefully no need to replace the spider.

I can't see any way of getting raw fuel running through the engine unless there is an injector issue. I had the same problem on an 86 corvette. It took me about an hr. to pull the injectors and replace them with professionally cleaned ones from ebay. End of problem util son wrecked it.. )-:}

My bro had this problem. There was a puddle of fuel under his tailpipe and dripping off the muffler. Turns out the PCM died and wasn't igniting one cylinder. I'm not saying replace your PCM. I'm trying to say it can be an ignition problem. Fuel may be getting delivered properly, but it's just going through unburned.

PCM???

ECM, VCM whatever. The computer that controls your engine.

timelessbeing wrote:ECM, VCM whatever. The computer that controls your engine.

ok... Gotcha... I shoulda guessed that but I'm at the office trying to do way to much at the same time I think..

ok.. so I decided to get motivated today. I started the van... let her run for about 20-30 minutes while cleaning it out in the cab area and making room / removing the doghouse. Anyhow I finally got the plenum removed.. got some pics below. maybe not the best and I forgot to take some of the spider. but it looks worse then the two I am posting of the plenum and intake area....

https://picasaweb.google.com/lh/photo/l ... directlink

https://picasaweb.google.com/lh/photo/w ... directlink

So my thing is considering the spider and fuel regulator look even worse. should I start with the $40 regulator then move to the spider? The thing I am looking at or considering if you will. Is the spider looks at teh injectors as though there is fuel on the tip of each of them. But I am trying to keep in mind that I had it started so if one is stuck open or stuck the vacuum would have started pulling the fuel through it???

Next thing is that I am thinking while it is all apart I really need to clean the plenum and the intake area as it is way to gum'd up.... But what is going to be my best option...??? I am really not sure what to use. Regular carb cleaner??

thanks for the help !!

Nathan

You probably want to test the valves/injectors for good spray pattern. Hopefully someone else can tell you how to do that. Maybe turn ignition on (but don't start), then manually apply 12V to each injector? I would also test for a good spark, which can be easily done by removing the plugs one by one.

By the way, here's how you post Picasa photos. Paste the link into your message, highlight it, and hit the "Img" button. Or use the forum attachments and preserve it forever for posterity.

I was thinking of hokking the power and gas lines back up to just the spider and see if the all shoot.... Dunno if it's a good idea or not or if it'll even work or not.

I found a couple of hits on what may help you to final repair...

viewtopic.php?f=50&t=7232&hilit=fuel+sp ... leshooting

http://www.astrosafari.com/viewtopic.ph ... ing#p27022

Good Luck, and Keep us posted.

Jim

EZ-OFF oven cleaner does a pretty good job of cleaning the sludge from the plenum.

I found it... I found it...

The ultimate, (or the best I could do answer for ya).

viewtopic.php?f=4&t=69&p=9527&hilit=injectors#p9527

Jim

PS The update eliminates a lot of PROBLEMS.

Smiliesafari wrote:EZ-OFF oven cleaner does a pretty good job of cleaning the sludge from the plenum.

How bout the bottom? That is just as bad or worse then the oil soaked plenum?...