Last post on Oct 27, 2013 at 1:07 PM
You are in the GMC Safari & Chevy Astro
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GMC Safari, Chevrolet Astro, Van
#1806 of 1973 Re: 1998 Chevy Astro Bogging / Stalling [jferrantelli]
Sep 04, 2008 (1:35 pm)
Could be the regulator but it's attached to the main computer for the injectors under the plenum, if it' a vortec which it probally is. My nephew has a 97 or 98 and has to replace the fuel pump every six months or so.His vapor locks and quits running like that and he started running with the fuel cap loose.I think some of the later model Astros have an issue with the emission control system where a fuel vent valve doesn't operate properly and vapor locks them or frys the pumps. I also had a problem with mine where the main wiring bulkhead that plugs in behind the battery and goes through to the fuse block was melting the main ignition wire and loosing contact and it would not start until it cooled down.I unpluged it cleaned it with contact cleaner and a small knife and crimped the main hot wire contact to fit tighter and it cured it,mines a 95. If it's not shooting a code then it's probally not ignition problem,usally they'll shoot a code.
#1807 of 1973 Re: Ticking/Knocking noise [spike99]
Sep 09, 2008 (3:56 pm)
Well, I don't think it it piston slap as I know what that sounds like as I have a 2001 GMC pickup with it. On this van, it just started knocking and had never done it before. So know everytime I change the oil I have to substite 1 QT of oil for 1 QT of Marvel Mystery Oil. If I don't, the knocking noise gets louder. Just wondering what I can do to see what the problem is.
#1808 of 1973 Re: Ticking/Knocking noise [joelmich]
Sep 09, 2008 (5:51 pm)
Piston slap is when an undersized piston is installed. Over time or in cold weather, the piston vibrates up/down the cylinder walls. Thus, "slapping" sounds. Especially under "First Start" conditions (when little oil lubrication) or when under colder engine climate conditions.
Another form of ticking is stuck lifters, stuck valves and other stuck internal engine parts. Sometimes, Oil additives (like Mystery Oil) can loosen those parts. And over time, the stuck part Magically starts working properly again. For more details of MMO, surf entire post and bottom comments of: http://classiccars.about.com/b/2007/12/28/marvel-mystery-oil-for-your-classic-ca- - r.htm#gB3
As a suggestion, keep using MMO in your engine. If MMO makes the engine ticking sound go away, then it must be a good thing to use. Sounds like some small amounts of MMO can be used in the gas tank as well. As my doctor often says, "if it works - keeping doing it".
Hope this helps as well...
#1809 of 1973 astro rough idle and stall
Oct 05, 2008 (4:57 pm)
We recently took our Astro on a trip to Washington DC. It ran fine for most of the trip. But on the way home it did not seem to have as much power on the hills. We took historic National Highway 40, which is a straight road, with monster grades up and down the beautiful hill country of Pennsylvania. A few days after getting home it died in town, had to be towed home. I coaxed a code 44 out of the computer, but that is where things went astray. Code 44 means a lean fuel mixture. But all the suggested fixes were dead ends. The oxygen sensor was recently replaced. I could find no vacuum leaks on top of the engine. I replaced the distributor cap and rotor. I pulled the plugs and did a compression test, it tested good. I replaced the plugs and wireset. Then I did something rash, I cut the catalytic convertor off, thinking it was just some high back pressure that was causing the rough idle and stall behavior. I was glad to see that my cat was perfect, too bad they are not bolt on installations. I checked the timing to see if the distributor or timing chain had jumped a gear tooth, timing was okay. I put it all back together, still had not fixed the problem. Then I did what any sane shade tree mechanic would do when faced with a code 44, I took the fuel filter off. I was careful not to spill the contents of it on the ground. I poured the fuel left in the filter on the back/dirty side of it into a clean container. It was amazing to see all the black specks and metal shavings that came out from the inside. I put a new filter on, and the problem was solved! I expect that the fuel pump might have been stressed by the bad gas, I would not be surprised if it went out soon. I will have a muffler shop put a new cat and muffler back up. But it is nice to known that our trusty Astro will be back on the road.
#1810 of 1973 Re: astro rough idle and stall [blackpacific1]
Oct 06, 2008 (5:21 pm)
A code 44 is lean mixture code which could be an oxygen sensor, but the idle sounds like an EGR problem which these ASTRO'S are notorious for. The plenum design with EGR in the front of it lets every piece of carbon that breaks off fall into the valve and stick it open. I would get a screenede gasket for the EGR valve which they make now I used to make my own and now they make them you can buy,pull the EGR valve and clean it out and install that screened gasket and it will save a lot of headaches in the long run. Those Vortec MPI ASTROS run like champs but they had major design flaws in the injection and EGR setup. I just replaced my injectors, the nut kit which is basically a plastic line setup inside the plenum and usually they start leaking around the o-rings but once you take it apart it's much easier to replace everything to make sure you got the problem fixed,because it's a several hour job pulling it apart.Those injectors are just plastic poppets basically spray nossels because the main injection body controls it all. DLM1
Oct 09, 2008 (6:58 am)
I have a 200o Chevy Astro and I have noticed the dutch doors appear to leak during a hard rain. This is espically noticeable on the passenger side. I have seen previous posts about this problem. What is the best method for resolving this problem?
#1812 of 1973 Re: astro rough idle and stall [dlm1954]
Oct 22, 2008 (5:17 am)
After replacing the cap, rotor, plugs, wires, fuel filter, and checking the coil and EGR valve, I decided to tow it into the dealer. I really hate to be in that position. I suggested to the dealer to check the fuel system since it appeared to run better after I replaced the fuel filter. He finally isolated the problem to a failed fuel pressure regulator. So my van has been spared from the scrap heap once again. I think maybe some of the black plastic and metal flecks that I found in the fuel filter belonged to the pressure regulator. It was one of those situations where I did not have the right tools or insight to find the problem myself.
#1813 of 1973 Re: astro rough idle and stall [blackpacific1]
Oct 22, 2008 (6:59 am)
I understand your position, that's a pretty complicated undertaking to take apart that plenum and injection system. Because without the proper tools it would be really hard, but good luck it'll probally run better than it ever did when you get it back if they replace everything which is what I do if I go to the trouble of disassembly. DLM1954
#1814 of 1973 Re: astro rough idle and stall [dlm1954]
Oct 24, 2008 (11:29 am)
Well, the replacement of the fuel pressure regulator did not solve it. I purchased a new fuel pump which the dealer is installing today. If that does not fix it, I'm giving up. So far the dealer has run up an $800 bill chasing dead ends. I wish I could rewind, since it is a lot less costly for me to be chasing dead ends. He claims the fuel pump is not putting out enough pressure, and that the fuel pressure leaks out when the fuel pump stops. My experience has been that when a fuel pump dies, it is sudden, not this costly lingering agony. But I don't have a fuel pressure tool in my tool box. Maybe next time I will. More to follow.
Oct 24, 2008 (3:40 pm)
I think he might have got you there, the fuel pump pressure should have been checked first thing, and it actually sounds like an open EGR valve which will probally be next on his list;and that to should have been checked first because a little piece of carbon in that EGR valve causes those Astros to run like crap and their notorius for it. The fuel pumps usally just go out they don't usally lose pressure they either work or they don't. I've only seen that happen very,very seldom. And loke you said they usally just go out they don't lose pressure, I think you might being getting played for parts you don't need and they will keep it up as long as possible. I would ask to see the low pressure reading, if it's there at all which I kind of don't believe. DLM1954