[The Scotsquatch]

Hey everyone! I just bought a 91 Astro with TBI, and it starts really hard. I replaced the battery, cap, rotor, and spark plug wires. I'll be putting in the new spark plugs sometime this week.

When I crank it up, I have to hold the key on...vroom vroom vroom...it takes almost 30 seconds to start it...it starts faster if I hold the gas pedal about half way down, but still takes a while. Once it starts, its fine, idles smooth, and drives pretty nice. There was some hesitation when I first got it driving it around, but I haven't taken it on a road test yet since putting in the new parts.

Any idea what is causing this? The TBI seems to be working okay...the fuel pattern seems equal from both injectors. The fuel pump is audible in the gas tank though...is it supposed to be loud enough to hear?

Thanks!

Kevin Smith
Siege The Day

 

[coolen]

Coolant temperature Sensor?

 

[davesyo]

check for stuck open EGR valve or bad coil maybe

 

[The Scotsquatch]

Well...I put in the new plugs, and it was still doing the same thing. So I siphoned out as much of the old gas out of the tank as I could (the Astro was sitting for a very long time before I got it...the old gas was a dark yellow!...ewwwwwwww!!!), and put in 15 gallons of fresh gas and changed the fuel filter. When I replaced the sparkplug wires, I noticed the temp sending guage wire was toast, so I repaired it and now the guage on the dash works again...yay!

So its not the temp sender...it works.

So...maybe the EGR valve or the coil? It still starts hard even with all the new stuff and fresh gas...but now once it starts, it idles right out smooth, and doesn't smoke or hesitate anymore.

Any more ideas what could be causing it to start so hard? Its a lot better, but still doesn't fire right up...If I push the gas pedal in now half way, it fires up in about 5-10 seconds instead of 30...maybe the injectors or the throttle body is fouled up with that old gas?

Could it be the catalytic converter? It smelled like rotten eggs when I test drove it after changing the gas...and it was dripping a lot of water out of the tailpipe before I changed out the gas...could it be blocked? And if so, can it be eliminated? We live in Florida where there isn't any emissions or inspection...can I get rid of the cat and just run a muffler without it? Will it be enough back pressure if I do? There is only 1 oxygen sensor on my 91, and it is before the cat, so that part shouldn't be an issue...any advice?

Thanks!

Kev

 

[The Scotsquatch]

Here is another question...should you be able to hear the fuel pump even with the tank full? It is pretty loud! I just noticed that if I leave the key on for a while without starting it, it starts a lot easier...could the pump be about to die? Or is air getting into the line? There aren't any leaks, but who knows?

Kev

 

[davesyo]

I would probably check fuel pressure first. If pump seems louder than usual it may be a sign somethings up with it.

 

[The Scotsquatch]

I'm not sure how loud these pumps are supposed to be, since we just bought the van not too long ago, and its my first Astro...and it has been making a racket since we bought it. The fuel pump seems to be in the stock location, unless some previous owner put an aftermarket pump on top of the fuel tank...I haven't dropped the tank to find out.

But its loud! Even before I gutted the van and removed the carpets, the fuel pump hums REALLY loud! It sounds like there is a very loud hair clipper under the truck. Is that normal, or should it be barely audible, like every other electric fuel pump I've ever had in a vehicle? You would think that if the pump was submerged in the tank, it would be quiet...and I just filled the tank. It is just as loud with an empty tank as with a full tank.

The gas guage still works though. I thought that the fuel pump and sending unit were a single system. Do I have that wrong? It really does sound like the fuel pump is sitting on top of the fuel tank.

Kev

 

[The Scotsquatch]

It was the fuel pump! Of course, my dumb *** somehow put the wiring harness on backwards the first time, so the new pump was running backwards...and I had to drop the tank TWICE to figure out why it wasn't pumping fuel...lmao! But now it starts right up, and runs like new, even with 215K on the engine...yes!

Kev

 

[The Scotsquatch]

All of the work I did so far didn't entirely solve the problem: The Astro starts now in 5-10 seconds instead of 30...So my guess is the fuel pressure regulator...it doesn't seem to be holding fuel pressure when you shut it down, and acts like you are repriming the lines when starting it up. Guess I'll have to pull the TBI, clean and rebuild it, replace the fuel pressure regulator, and then replace all the electronics like the TPS before putting back in the TBI...I'll let you know how it goes!

Kev