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Roy
Roy, import/domestic specialest
Category: Chevy
Satisfied Customers: 5158
Experience:  ASE master tech for 40 years
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Astro -95 suddenly after working fine, begun to idle badly

Customer Question

Astro -95 suddenly after working fine, begun to idle badly and died after about 30 sec. When pumping on gasspedal it worked in about 30 sec. again. HIGH blowsound from intake. Fuel pressure dropping from 56 psi to 48 psi in about two hours. Living in Sweden and hoping for help. // Michael.
Submitted: 1 year ago.
Category: Chevy
Expert:  Roy replied 1 year ago.

good morning my name is ***** ***** I will assist

what was the exact fuel pressure???

do you have 2 injectors on top the throttle body or the spider unit???

Roy

Customer: replied 1 year ago.
Its 10 pm here in Sweden, so I hope to contact you again tomorrow afternoon if thats ok ??
I have the spider unit by the way. // Michael.
Expert:  Roy replied 1 year ago.

that is fine

Roy

Customer: replied 1 year ago.
Hi again. Now I am home from my work and could continue with my Astro.
Are you there and got time to guide me ??
Expert:  Roy replied 1 year ago.

yes, it sounds like you either have a failed spider or a fuel pump. the pressure should hold better.

Roy

Customer: replied 1 year ago.
My fuel pressure was 60 psi while cranking, and dropping to 56 psi when turning key to off. During the following two hours the pressure whent down to 48 psi.
Now, about 24 hours later the pressure is 32 psi.
Expert:  Roy replied 1 year ago.

ok, that is good. have you cleaned the throttle body for the idling issue???

do you have a scan tool to monitor the long term trims???

leaking fuel pressure regulators are a common failure for this as well.

Roy

Customer: replied 1 year ago.
I have not cleaned throttle body, and do not know for sure what that is. What scan tool do you mean ?? I have checked the codes from the pcm, and I doesent get any fault codes at all.
Expert:  Roy replied 1 year ago.

follow the air filter inlet to the throttle body. it has a flapper plate that carbons up. a scan tooll is conneted to the aldl connector under the dash and reads computer information

Roy

Customer: replied 1 year ago.
I have no fault codes from the OBD under the steering wheel, just the repetetive start code, one blink followed by two blinks.
Expert:  Roy replied 1 year ago.

thats a code 12 and that is normal with engine off.

not looking for codes, just looking for the trims to determine if it is running rich or lean.

Roy

Customer: replied 1 year ago.
How do i get these "trims" as you call them ??I just remember that a friend was looking at the throttle when the engine was running and had this strong sucking sound, and he claimed that the throttle was not moving when I pressed the gasspedal. I did not react when he told me that, but now when you mentioned it, it sounds like the throttle is carboned up. I had no idea that this could happened.
Expert:  Roy replied 1 year ago.

you need a scan tool that can read data from the ecm

Roy

Customer: replied 1 year ago.
well, I dont have that tool availiable.
What about my fuel pressure, is it ok in your opinion ??
Expert:  Roy replied 1 year ago.

yes, from the info you gave me, yes, it is good

Roy

Customer: replied 1 year ago.
Ok then, ill check the carbon and get back to you when i am done.
Expert:  Roy replied 1 year ago.

ok

please dont forget to rate me as it is the only way I get paid for my efforts

Roy

Customer: replied 1 year ago.
of course, but is the problem not suppose to be fixed first ??
I have to more questions. Is the throttle suppose to move when the gasspedal is compressed ?
Do you have a suggestion on to how clean the throttle flap ?
The throttle house is a part of the upper half of the plenum, and a very hard part to clean when in place.
How does the car react if the TPS is out of order ?
Expert:  Roy replied 1 year ago.

you can rate at any time

yes, when the pedal is depressed, it will open.

use 2plus 2 carb cleaner

if the tps is out of range it will code.

Roy

Customer: replied 1 year ago.
I have a chilton repair manual, and the cable to the tps had 5 volts and a backprobe show 0,59 v closed, and 4,53 v at full throttle. That is almost exact as it should be, so I guess that it works like it should.Ok, carb cleaner of some brand here in Sweden. What I dont get is how to clean the flap and house. Is the carb cleaner suppose to go eith the fuel ? In the throttle on this car it is only air, no ?? By the way, the flap is not stuck in the house, just a black ring around the flap and on the walls of the house.
Customer: replied 1 year ago.
Picture in the house w flap, but do you think thats the problem ??
Customer: replied 1 year ago.
I give up for today. I will ping you tomorrow again if thats ok. // M.
Expert:  Roy replied 1 year ago.

after noon

Roy

Customer: replied 1 year ago.
Im sorry, but I just got home being to the vet with my dog and do not have any energy left to deal with the car today. I hope thats ok anyway, and I will try to do better tomorrow afternoon.
Do you work weekends to, or is your help only available weekdays ??
// Michael.
Expert:  Roy replied 1 year ago.

weekends are better. I am on and off during the week

Roy

Customer: replied 1 year ago.
Ok, super. I'm often tired after work at weekdays so to do this on the weekend sounds nice.
Have a nice day then. // Michael.
Expert:  Roy replied 1 year ago.

thanks

Customer: replied 1 year ago.
Hi again Roy.
I suppose that it's quite early at your end. I think we have 8 hours timedifference between us, so it's almost three a clock in the afternoon here, and I'm ready to start butting head with my Astro.I will start fiddeling with the car now and you can send me an answer when you feel ready.
// Michael, Sweden.
Customer: replied 1 year ago.
Hi again.
I don't know exactly how this "ask for help" works, but I'm getting a lot of mails asking for my grades of your help. Like I mentioned to you before, "arent I suppose to get help to fix my car first, and leave my opinion of the help when it's done ??"
I suppose that this mails is automatic generated and not sent by you.However, today I have checked the distributor and the order of fireing, spark, cleaning the throttle housing and flapper, and now I'm trying to get the old gas out of the tank with the pump.What makes me write this mail is that the pump does it's job for a couple of seconds, like when you are starting the car.
Then the pump stops pumping after this couple of seconds, even though the line is open without any pressure buildup. I have the pressure tester mounted with the evacuation button fully open, so the gas can flow straight in to the gascan.Another thing is that in the Chilton repair manual it states that the key has to be off for 10 seconds before the pump will start pump it's cykle again, but that's not happening on this car.
I can turn the key off, and back on again directly, and the pump will start pumping upp pressure again.I have no idea if you will find this ranting helpful for your diagnosis of my car, but I don't know how to do this any other way.
// Michael, Sweden.
Expert:  Roy replied 1 year ago.

the fuel pump will only run for 2 seconds with key on engine off. it will start running again when the engine cranks to start.can you check the actual fuel pressure??

Roy

Customer: replied 1 year ago.
Like I wrote before."My fuel pressure was 60 psi while cranking, and dropping to 58 psi when turning key to off. During the following two hours the pressure whent down to 48 psi.
About 24 hours later the pressure is about 32 psi."However, after checking the things I wrote about, the engine wont start at all, just getting wet on the sparkplugs. Tried and filled 10 liter fresh gasoline without any different result.
Before it always started directly, but died after a while. Now it's not.......... ūüėĖ
Expert:  Roy replied 1 year ago.

ok, do you have spark at the plugs cranking??? lets back track and check the basics again.

Roy

Customer: replied 1 year ago.
good spark on every plug. All cables at the right plug. Nr.1 at tdc when rotor points att it's cable.
Could it be something wrong with the timing belt ?? I have never experienced that, but it obviusly happends sometime.Before all this the engine acted a bit strange. When cranking it sounded like the compression worked against the engine, if you know what I mean ??
It did not even have the power to rotate without stalling, and in the next minute it could start. Almost like it was high ignited one minute, and ok the next. All that at the same time as the high suction sound coming and going from the intake housing and airfilter.
Strange engine this. // Michael.
Expert:  Roy replied 1 year ago.

ok, can you do a compression test??? you can rent a tester at a parts store.

Roy

Customer: replied 1 year ago.
Already done with ok result on all cylinders.
Expert:  Roy replied 1 year ago.

what was the compression???

Roy

Customer: replied 1 year ago.
Sorry for the delay. The compression was around 90 psi on all cylinders. I only had a meter that you press down against the plug hole, and as you probably know it's not easy to do that on an Astro concidering the lack of space.
Expert:  Roy replied 1 year ago.

90 is low. if you have spark, fuel and air, and have low compression, I suspect a worn timing chain.

Roy

Customer: replied 1 year ago.
What symptoms could I see if the chain is worn ? Is there a way to test if its worn before ripping the engine apart ??
I long suspected some timing, spark or electrical problem but not really know how to be sure.
Expert:  Roy replied 1 year ago.

remove the front cover and inspect. the water pump has to come off to access the timing chain cover

Roy

Customer: replied 1 year ago.
I have the Chilton book to look in, but is there no test to do before I start to remove the waterpump and all that. It sucks to remove everything just to find out that nothing is wrong with the chain..
Expert:  Roy replied 1 year ago.

with your issue of compression, it will definitely show wear

Roy

Customer: replied 1 year ago.
Could the chain jump over one or two links ? When I was fiddeling with the distributor I was unsure if I turned it one half revolution wrong so I tested and turned it. Then if I turned the distributor as long as I could one way, the car started but died as soon as I touched the gasspedal.If that is just wear, does it not have to be a lot of wear to do that ? To get the car started with the distributor that much wrong, something in the timing has to be really wrong, doesn't it ???Sorry for all my dum questions and repetitions, but I just want to get the picture clear in my head. // Michael.
Expert:  Roy replied 1 year ago.

it stretches and retards the timing which effects the compression

Roy