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350 tbi won't idle or drive


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Texandian
Novice

Feb 20, 2017, 12:01 AM

Post #1 of 14 (269 views)
350 tbi won't idle or drive Sign In

I was given a 1990 chevrolet cheyenne. 2500 and finally got it home. It had sat for about 6or 8 years. I put a battery in it, new fuel pump and filter and primed the throttle body and it started right up, it idled well considering the circumstances. I was able to drive it across the subdivision and back, about 4 miles with no problem. And again the next day just a block and back. On the second, short trip it began to be difficult to keep running when in gear. (it's A/T btw) gradually but quickly it got worse. Now it would not run unless I was constantly and gently pumping the throttle. I have cleaned the throttle body, tested the iac and tps with a multimeter, adjusted ignition timing, and looked for vacuum leaks with starting fluid. After the timing adjustment I was able to get it to idle but it was mildly to moderately rough. I thought I was on my way but when I put it in gear it begins to sputter and backfire. I can't even get it 30 feet before it dies. It does not jump forward forcefully or jerk it just idles down and then spits and shutters till it dies. It will start right back up but usually afterwards it USUALLY will not idle. It seems there is little difference in the engine temp. I'd like to get some some ideas for troubleshooting but I have very basic tools and no access to most tools needed for testing (i.e. Vacuum pump, pressure guages, etc.) any and all useful information will be greatly appreciated. 1990 cheyenne 2500 5.7l tbi 2wd service bed


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Feb 20, 2017, 2:58 AM

Post #2 of 14 (259 views)
Re: 350 tbi won't idle or drive Sign In

Quote you ">>I have very basic tools and no access to most tools needed for testing<<"


Just how can anyone proceed with that? No tools or access to them!


Then just what did you do to mess with timing now highly suspect along with fuel unknown if totally clogging up things this fast. If you had a timing light where did you begin and where did you leave timing at? It shows a vacuum advance distributor for 1990 and should have instructions on a sticker under hood how to do this even the specific # you want.


More concerned about the fuel and sitting 6-8 years bet you can just dump new fuel filter out now from inlet into a glass to see what junk made it that far.


Sorry you messed with the timing - it doesn't get messed up by itself rather stays where it was set last time it was worked on and if known right don't touch that,
T



Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Feb 20, 2017, 5:30 AM

Post #3 of 14 (255 views)
Re: 350 tbi won't idle or drive Sign In

Yes, I agree. Unless you know the specific procedure for timing this vehicle AND have a reason to believe it would be out of time in the first place, You should not have touched it.

Your first step now is to test for any stored trouble codes, then maybe see if the EGR is stuck.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



kev2
Veteran
kev2 profile image

Feb 20, 2017, 10:42 AM

Post #4 of 14 (239 views)
Re: 350 tbi won't idle or drive Sign In

6-8 years sitting..... might want to follow toms thought - FUEL, filter, - did you refuel ?
Timing - are you familiar with this - maybe set timing connector is open?
Try a code search too easy to not try. post any codes --


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Feb 21, 2017, 12:09 AM

Post #5 of 14 (216 views)
Re: 350 tbi won't idle or drive Sign In

Other thoughts if in fact this is HEI ignition AND has a vacuum advance. The ignition module inside distributor the wires bend with each movement of the vacuum diaphragm and can break unseen or rub and partly short. Plain look for that - wiggle test connections at both ends of that module and where it plugs in to distributor.


Not sure but for 1990 could be a few different engine emissions specs, California, Federal or High Altitude and you should see that on a sticker if still there and all is original,


T



Texandian
Novice

Feb 23, 2017, 8:11 AM

Post #6 of 14 (193 views)
Re: 350 tbi won't idle or drive Sign In

I am a carpenter trying to play mechanic so I apologize for the lack of knowledge of these issues and procedures. And I very much appreciate all advice and information given. First thing I did was drop the fuel tank and clean it. I replaced the pump and filter so I don't think the problem is there but again I'm not a mechanic. I will take Mr Greenleaf's advice and take the the filter off and inspect. When I messed with the timing I felt like I was getting somewhere. I was able to get it to idle much smoother with just a very small amount of throttle. It even idled in gear. But it didn't stay that way long. It seems like every time I think I made some progress and try to drive it, it reverts back to the same place I started. I now also have a problem with the transmission. I believe the torque converter to be specific. When I put it in gear in won't engage until the rpms are up then it engages harshly. Again, thanks to everyone for any help, advice, tips and information.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Feb 23, 2017, 8:37 AM

Post #7 of 14 (191 views)
Re: 350 tbi won't idle or drive Sign In

It's OK - I need a good carpenter like at least one that knows which end of a hammer to use on nails!


This sat so fuel FYI doesn't last that long much less 6 months. That's where you now already changed the pump with a sock I hope and the fuel filter. If either that sock which could catch too much or it ran a bit you'd see crap in the new filter and hopefully any harmful junk stopped there. Said you would see that dumping it into a clean glass jar now. It's too new for anything if this was a routine on a vehicle that was used all the time or at least not that much time.


What to do if you find debris is probably take the tank right out if unrusted enough for straps and fuel neck cooperates too all available new if all else fails but try to clean it out. IDK - some have baffles inside so built in you really can't just flush out a tank very well and if that far you'd see the sock on the fuel pick up all clogged or part clogged up?


Hard to say as certain areas for fuel use different products that go bad and being old is it rusted inside by any chance. Trick - rust dirt picks up with a magnet! NOTE THAT AND THAT IMO MEANS TANK HAS TO GO!


Other things actually quite a few things happen from just sitting that will show up now as you use it again unless totally prepped for storage a lot of things to do especially if not in a climate controlled area where it sat,


T



(This post was edited by Tom Greenleaf on Feb 23, 2017, 8:44 AM)


Texandian
Novice

Feb 23, 2017, 7:27 PM

Post #8 of 14 (165 views)
Re: 350 tbi won't idle or drive Sign In

I took the tank out, used a hand siphon pump to empty all but a half gallon of gas or less out. Then I filled it with a lot of large gravel and nuts and bolts and rolled it around the yard for a while. I know i got at least the better part of the rust and varnish etc out of it. I then took it to a car wash and pressure washed it. Dried all the water as best I could and then I put the new pump and filter on. And it ran pretty good for at least a half hour and gradually got worse from there. As I mentioned before, I will check all the suggested things out. This weekend. I'd be thrilled to just get it back to driving around the neighborhood.

I've been learning the carpenter trade for close to 30 years and have been working for about 20 years. My grandpa, 78 years old, taught me. I still work for him he is still working too. We do everything residential except installation of the hvac systems.

Thank y'all again for the info etc


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Feb 23, 2017, 10:45 PM

Post #9 of 14 (155 views)
Re: 350 tbi won't idle or drive Sign In

OK - So you did what makes common sense and I would do something like that as well followed by a product never used that's coats the entire inside, dries to something like a rubber coating that is fuel proof once listed for obsolete tanks for restorations or whatever reason. I never did and always tossed tanks for new available for ages or a custom shop not needed for restorations or just repair of gas tanks. Acid dunked type things once common is about gone from my area.


This is a great watch from YouTube on making gas tanks new and shows the baffles I speak of. Truth is I never cut one open just know as you try to siphon out tanks a hose doesn't always work well getting all twisted up either chance or by design will NOT drain a tank empty rather at best close, some not much at all.


Good watch: You can skip along as it's over 5 min. long and look at the 2 min. area especially shows what I'm talking about............
https://www.youtube.com/watch?v=52sJ_BxMi64


This is actually newer for vehicles that might be just an open shell with the ports for vents, fuel pump and or gauge and way to do a filler neck. It/they don't just crush flat to dispose of easily.


Smile friend - you still have a tank full of the larger rocks in gravel and the nuts and bolts in there now! You'd never get them out so it's wrecked and need a new one just for what you did which makes sense but now no way to get that stuff out.
Alone it might be clean enough for the short run to work even longer than it did. Now it's about sure gas is the issue to deal with which will begin with a new tank and checking lines and a bunch of new gas filters anyway. Some solvents and find the port up at engine to open and blow it all out dry. Even 1990 and lots older lines everywhere, injected on this and lines on to and from evaporative emissions vapor capturing has be done for ages.


This computer is going to explode looking around so will post on an edit or new post a new tank of many possible for exact fit for this. Trucks would be available with regular size up to maybe 40 gallon and definitely dual tanks which might make each different - can't know so will go looking.


All US areas TMK us ethanol in gasoline. Texas is one place that sells the E85 means 85% of that alcohol. Trouble with any is it has to be used up and will NOT stay mixed and will separate like you see commonly in salad dressing or plain oil and vinegar without debris you'd shake that and use quickly. For fuels it stays mixed for just a short time then you are picking up just the fuel or the alcohol not a good mixture to put thru the system. Additives are a high % of what's in so called gasoline! Very high amounts of stuff for a region or seasonal changes known by me over 200 formulas by the refineries most in Houston area as you would or should know. Been there, family lived nearby as well, many visits and travel around TX personally. Spring, TX a section of Houston by chance.


Sorry for the book it needs it. Let's now find a new tank for this as it trashed now.


Side note - you seem like a great sport - bear with me. Carpentry and auto mechanics have been a non crossed trade or way of thinking such that it's a bad joke that most carpenters I've known had the worst vehicles - creative repairs for damage, home made boxes - old station wagons with interior removed or some pretty wild stuff.


Off to price out and find what's available new for this which can only be a guess at exact fit replacement so you'll need to find out what it is. May say inside glovebox on a sticker (my own '97 still does) say the option list for the vehicle/truck, a Chev no less also just a tad newer but they've done that for ages too,


Tom



Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Feb 23, 2017, 11:12 PM

Post #10 of 14 (153 views)
Re: 350 tbi won't idle or drive Sign In

OK - many types and prices as I knew. Just example from AutoZone's site as they are easy to look up on line or choose any. That or plain call and get questions for your specific truck and tanks available for exact fit for what you have.


Disposal is your problem now. Varies by area what to do. I used to drive over them as flat as possible and washed dry of fuel or cut up with torches - super dangerous if any fuel possibly still in one.


Salvage/junk yards would take one empty no doubt - if troubles locally ask around parts places and junkyards.


Fuel neck and or new pump again (sorry but it's probably wrecked now already) and rubber parts, ground strap you may have noticed all have to be exactly right - no faking it on how it's grounded both for pump and for static electricity so they don't all instantly explode!


Here's the link not a picture. NAPA, any parts outlet on line or in person might be more helpful. Used might be possible as many don't last this long and might have a fairly new one at a junk yard AYOR on used stuff all the way.
http://www.autozone.com/...8_591468_11211_40145
(not suggesting this company and not a sponsor here just using the site for it's info and pictures as needed. BTW links generally not allowed unless yours or just pictures not advertising please)


You may have noticed or it was missing but think this has rubber on top so it doesn't rub thru. Should be the same as what I call "ice dam shield" for home roofing! Peel and stick crap by the roll - off to a home center for that as needed or again ask around at parts places.


This is step one and there will still be problems because it sat. Seals on axles, brake parts, driveshafts to gearcases, water pump didn't like sitting nor other things throughout will show up as you use it for months to come take each one by one as they happen a hope only minimal surprises which can't all be known right now,


Tom



Texandian
Novice

Feb 24, 2017, 10:59 PM

Post #11 of 14 (133 views)
Re: 350 tbi won't idle or drive Sign In

It's not an issue with pressure or volume of fuel. Everything looks good. The pressure was 12psi. Fuel, crystal clear. Once more, we all know I'm not a mechanic. But I sure think it seems like a vacuum leak. I can't seem to find it though. What are symptoms of high vac? Maybe something is stopped up in the throttle body?


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Feb 25, 2017, 6:24 AM

Post #12 of 14 (127 views)
Re: 350 tbi won't idle or drive Sign In


Quote
What are symptoms of high vac? Maybe something is stopped up in the throttle body?


How can you be so sure your problem is a vacuum if you don't even understand what a vacuum leak is?

EGR leakage at the base plate was pretty common in these.

You will probably need a smoke machine to do the testing for this or vacuum leaks.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Texandian
Novice

Feb 27, 2017, 6:30 PM

Post #13 of 14 (103 views)
Re: 350 tbi won't idle or drive Sign In

OK, I had some time to work on the truck today and also a little Friday and Saturday. I took the fuel filter down, it and all the gas that was spilled was very clean and clear. I pulled all the plugs one by one. Two or three of them were pretty crudded up with what I guess is either baked oil or carbon. One of the gaps was bridged. I cleaned them up and put them back. I was able to get a hold of a timing light and following procedure set the ignition timing. I've made some progress albeit a small step. The truck idles much much smoother and will stay running without any help. It still has the surges but they are farther apart. (it runs smooth longer between each surge and it runs smooth longer than the duration of each surge). I was even able to drive it up to the next block and back. However, when I was making the u-turn it began a new different behavior. I had to find a "sweet spot" in the throttle to keep it moving. Too much throttle and it would stall. And when that would happen it seemed like I could hear an excess of air being sucked into the TB and the combustion sounds were muffled by that sound. Still no codes coming up.

I am grateful for the information and direction that I'm getting from you all. But those of you who would like to speak down to me (or type down rather) as if I am inferior, I have a feeling that you started learning your trade at some point in life and until you learned enough to feel superior to others you made assumptions based on logic and the knowledge that you had at the time. I'd like to think that I deserve the same respect that put forth. Thanks.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Feb 27, 2017, 6:52 PM

Post #14 of 14 (101 views)
Re: 350 tbi won't idle or drive Sign In


Quote
I have a feeling that you started learning your trade at some point in life and until you learned enough to feel superior to others you made assumptions based on logic and the knowledge that you had at the time.


Yes, I started when I was 12 years old practicing on lawnmowers in the back yard. Then I spent 4 years in a trade school learning how to do the very basics with an instructor standing over me at all times.

Then I spent about 20 years learning the trade before I ever attempted to diagnose a problem with a computer controlled car.

If you think diagnostics are as simple as asking a few questions on a forum, you are in for a surprise.

We can answer technical questions and supply diagrams but we can't download 20 years of knowledge into your head.

PS, if you think it's OK to simply brush off caked up spark plugs and put them back in, we are going to be wasting a lot of time here.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



(This post was edited by Hammer Time on Feb 27, 2017, 6:54 PM)






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