1996 Astro van starting issues

1996 Astro Van. cranks, good spark, good fuel, may idle, but falls on its face when throttle is touched (like it is starved for fuel). Once you get it to actually start & idle, it idles fine & will crawl around
the parking lot in gear without problems. But hit the gas, and it will stall.
If you crank it over & over, it will not start. You need to bump the key over & over to get it to start, or else it will flood. Will not start in "clear flood mode"
Replaced: Fuel pump Fuel Filter Fuel regulator Fuel Injectors Tested fuel pressure, very good Throttle position sensor Coil Electronic spark control Wires Cap & Rotor Plugs Quadruple checked firing order. ECM Cam sensor Checked for vacuum leaks around the intake.
I am at a loss of what to do next. Anything that could affect the running of this truck in open loop has been replaced (as far as I know)
On the scanner:... No OBD2 codes or faults. Everything is within parameters. No exhaust restrictions, no intake restrictions.
It sounds like I'm missing some other fuel control piece that may be the answer. Something is not telling the fuel to release above an idle.
As of now, the dealer is baffled.
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Sounds to me like water in the gas.
Ill tell you a story. Sometimes I get to go out of town to work. (Diver/harvest freshwater mussels) Went to South Texas once, was making some good money, me and several other guys. Hanging out at the watering hole, some guys brag about what kind of money they make, it makes the hometown boys a bit miffed. Long story short, someone either pissed in or poured a beer or two in my gas tank. When I went to leave, my truck acted exactly as you describe yours to be. It would idle fine, but would not take acceleration at all.Lucky for me my old 3/4 ton 454 had dual tanks, I switched over to the other tank and the truck ran fine. I found an old country dirt road (werent to hard in Texas) and drained off a gallon or so from the bad tank and it was ok.
Id try siphoning off/draining at least a gallon from the bottom of my tank were I you, and see what happens.
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What is the fuel pressure at the rail when this occurs. Was all this work done to correct this?

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What is the EGR doing as well.
Shep wrote:

--
Steve W.

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Hi:
Have you looked at the pickup in the distributor, since it's a 96, it should have a cam position sensor in the distributor, and a crank position sensor in the timing cover.
Try doing a scan, and a crank position relearn, look at the cap, the HEI 3 Enhanced is a pain in the ass for caps and rotors, and usually wipes out the Cam position sensor.
At the very least, do a code scan, and look at the crank position timing + or - 2 % is the max, but now that I might get back to work next month, I do what I always did. O% is my tolerance.
I hope this helps,
RK

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Thanks for the replies... but I'm afraid that I had already tried all of those.. I failed to mention that the EGR was looked over. Fuel pressure is at 65 consistent. Fresh fuel is in the tank. Cam sensor was already replaced. All other tolerances are perfectly fine on the scanner. No codes. Typically with cam & crank sensors, it's an all or nothing deal. Since it will eventually start & idle, and smoothly at that, I doubt there's a cam or crank sensor issue.
Now, there's a sensor just 2 inches behind the TPS on the left side of the intake. This has not been touched yet. I am not familiar with this one.

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I still feel like you have water. Just for kicks, disconnect the line at the TB, stick a clean jug/bottle on it and key on for a few seconds and look at what you get. Even if the tank was completely drained and refilled, there is a lot of line there to retain bad gas till it gets pumped through. Even if Im wrong, its a cheap/easy test. Just be carefull to let the pressure off easy.
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Have you checked the exhaust backpressure?
RK
wrote:

I still feel like you have water. Just for kicks, disconnect the line at the TB, stick a clean jug/bottle on it and key on for a few seconds and look at what you get. Even if the tank was completely drained and refilled, there is a lot of line there to retain bad gas till it gets pumped through. Even if Im wrong, its a cheap/easy test. Just be carefull to let the pressure off easy.
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Yes I replaced the cam sensor, and yes I checked the exhaust (both were listed in the initial message) As far as water in the fuel... I've let the truck idle in the driveway for 3 hours. The gas tank was almost empty when the problem started. Now I have a 1/2 tank of fresh fuel. It's safe to say that the fuel quality isn't an issue.
Again, I appreciate the help... but I need to hit on something that hasn't been changed/altered/replaced. What is the sensor that is right behind the TPS on the left side of the throttle plate housing?

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BLB wrote:

Ok you state that if you crank it it won't start and instead it floods. But if you bump it it will start and may idle OK?
How do you know it floods? Pulled the plugs and they were wet? ( I hope)
When you do get it to run and step on the throttle how does it die? Does it flood out or does it just QUIT.
When you say you changed the injectors is this a TBI truck or a MPI? Missed that if it's there.
When it quits do you see fuel still coming out of the injectors (if it's TBI)as it shuts down or do they taper off and stop spraying? If you spray some fuel into the intake as you open the throttle what does it do? What does the coolant temperature sensor show with a cold engine?
For testing purposes disconnect and plug any external vacuum connections, like the one for the EVAP system, the brake booster and whatever else. Any change?
What condition are the engine and chassis ground straps in?
--
Steve W.

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Hi Steve:
If it's a TBI he can hook a timing light to the number one cylinder and observe the spray on driver's side injector, and on the number two cylinder for the right side injector.
I think the sensor, as he calls it behind the TPS might either be the Idle Air control or an Intake Air Temp sensor.
Sounds like maybe out all of the shit that was changed, one bad part was replaced, and a defective new one was put in.
You need to do diagnostics. Not shit parts at it, but I would say but a vacuum gauge on it, and run it into the cab, and maybe you'll see a vacuum fluctuation. Maybe a loose converter core. Do you have the ability to check spark KV?
RK
wrote:

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i see no mention of testing or replacing the map sensor or mass air flow sensor,,what ever type you have,,try it it might just run then,
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