Main IndexAuto Repair Home Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN







89 chevy truck staling


First page Previous page 1 2 Next page Last page  View All Email This Post



lhanddh
User

Jan 16, 2010, 2:21 PM

Post #1 of 35 (7126 views)
Shortcut
89 chevy truck staling Sign In

1989 chevy truck 1500 4x4 5.7 250,000 miles keeps staling after warm up when you come to an idle


Tom Greenleaf
Ultimate Carjunky / Moderator


Jan 16, 2010, 2:52 PM

Post #2 of 35 (7120 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

At the miles and age it's open to about anything. If it can run well off idle I'd be looking for vacuum leaks first with the symptom of warm only as it would naturally have some extra fuel when cold to cover a leak for a while.

Do you know what's been done and how long ago on this?

T
_________________________________________
Long retired now


lhanddh
User

Jan 16, 2010, 3:09 PM

Post #3 of 35 (7116 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

new moter and trans about 5 years ago, in the past 2 months i have changed all vacum hoses, egr valve ecm, tps, idle air control valve, compleat tun up, put it in a shop and had a compleat test done on it. all they could find was plug wiers and replaced them again. still same problem.


Tom Greenleaf
Ultimate Carjunky / Moderator


Jan 16, 2010, 3:44 PM

Post #4 of 35 (7109 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

Ok: Vacuum leaks can still be gaskets not just hoses. I think this should be TBI = throttle body injected which could need cleaning - carb cleaner type thing. I shudder to say spray areas with carb cleaner for suspect leaks as it can catch fire so perhaps using brake cleaner or plain water would be safer if not accustomed to that. When and if a leak is found the idle will change.

Places to look/check are base gasket of throttle body and where intake meets heads. Also the EGR shouldn't react. Don't go nuts with sprays that could be flammable as they can flash as said so if you try that (your call) pin point one spot at a time - let dry and move on. I haven't used brake cleaner which can hurt paint and rubber items but most is marked not flammable - can't speak for every brand of anything. Water (easy on hot stuff) would be safest.

If in doubt - DON'T! Let a pro check it but so far it seems like a common vacuum leak to me,

T
_________________________________________
Long retired now


lhanddh
User

Jan 16, 2010, 4:05 PM

Post #5 of 35 (7104 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

put all new gaskets and fuel regulator on tbi, i will try and check where intake and heads meet. thanks for the help.


Tom Greenleaf
Ultimate Carjunky / Moderator


Jan 16, 2010, 4:48 PM

Post #6 of 35 (7096 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

Recheck torque on the new gaskets as some require it! If you find intake to head issue I'm pretty sure those are 9/16th and gently snug up if loose - center first, criss crossing sides just easy by hand till end bolts. It's an all iron engine and manifold I think (could be wrong) and tolerant. If not iron only use exacting torque specs and order - been a while and I don't have specs at hand.

Good basics to those engines, fundamentals date back to the Flintstones!



T
_________________________________________
Long retired now


lhanddh
User

Jan 16, 2010, 4:58 PM

Post #7 of 35 (7091 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

thank you, i will try that tomarrow and let you know how it goes, and thanks again for your time.


Sidom
Veteran / Moderator


Jan 16, 2010, 11:27 PM

Post #8 of 35 (7081 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

Just a quick check. Disconnect the vacuum from your EGR valve and see if it makes a difference on your problem.
I see where you changed it but try it any way, it just takes a minute..........






__________________________________________________________________________________________



lhanddh
User

Jan 19, 2010, 1:33 PM

Post #9 of 35 (7069 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

havent been avoiding you, took truck back to shop that worked on it, dumd asses ran the plug wieres across the ex. manafold and bund them up.they said they would fix them and check the rest out for free. i will let you know what i find out. and thanks again for your time.


lhanddh
User

Jan 21, 2010, 5:27 AM

Post #10 of 35 (7062 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

they said the rod that goes through the tb tahd the tps is hooked to the hole is wore out and it needs a new tb. said that is where the vacume leek is.


Tom Greenleaf
Ultimate Carjunky / Moderator


Jan 22, 2010, 6:40 AM

Post #11 of 35 (7051 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

If you carefull spray some carb cleaner at suspect area away from norm air intake and idle changes for better or worse there is a leak there,

T
_________________________________________
Long retired now


Loren Champlain Sr
Veteran / Moderator


Jan 25, 2010, 9:26 PM

Post #12 of 35 (7037 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

   

Throttle body worn out?Unsure It's possible, but if the engine is running lean, you'll be able to suck in liquid most anywhere. These had a problem with 'sucking in' the TBI to manifold gaskets.
To add; If the throttle plate bushings are worn, they can be replaced without having to replace the TBI.
Loren
SW Washington


lhanddh
User

Jan 27, 2010, 3:25 PM

Post #13 of 35 (7019 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

thank you, sprayed all around intake, throttle body, egr, and the idle did not change at all.


Tom Greenleaf
Ultimate Carjunky / Moderator


Jan 27, 2010, 7:52 PM

Post #14 of 35 (7012 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

A maybe: The EGR has a pintle which seals it shut when cold (or supposed to) and at idle. This could not be sealing tight unseen without taking it off and cleaning it. A new gasket may be required and if you use some high temp silver grease on new gasket it usually will come apart and be reusable.

This pintle is essentially like a needle valve for a carb. It allows some exhaust gasses to enter incoming new mixture to cool oddly the temp of combustion to lower emissions. They don't always seal tight and it shows at idle speeds when it should be sealed tight.

That would be consistent with it only having a problem when warm as there's enough extra fuel while cold to cover it and not when warmed up.
When removed it may look like this one with the pintle hidden in this example. It's just a cone usually to block the passage of gasses when not called for and sometimes can get deposits on it and not seal. Carb cleaner and strong solvents can clean them up while off vehicle. They should be spring loaded to be shut and vacuum opens them when it's called for. It shouldn't work when cold, idling or full throttle and load. It wouldn't show up with it installed with any spray tests. For the price of a gasket it's worth looking at and attempt to clean IMO with the complaint of stalling you have, T
_________________________________________
Long retired now


lhanddh
User

Jan 28, 2010, 6:49 AM

Post #15 of 35 (7004 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

ok, but i have already replaced the egr valve with a new one about a month ago, could this have alredy cloged up, and if so is there somthing i can change to stop this from happening again.


Tom Greenleaf
Ultimate Carjunky / Moderator


Jan 28, 2010, 6:56 AM

Post #16 of 35 (7001 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

Not likely - sorry if I missed that,

T
_________________________________________
Long retired now


lhanddh
User

Jan 28, 2010, 6:17 PM

Post #17 of 35 (6995 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

THATS OK, I THANK YOU FOR YOUR ADVICE ANYWAY.


lhanddh
User

Jan 29, 2010, 7:15 PM

Post #18 of 35 (6980 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

with it being a new EGR could it still be a bad one without it flashing a code for the EGR valve.


lhanddh
User

Feb 6, 2010, 3:01 PM

Post #19 of 35 (6948 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

does anyone know, is it posible that it is the o2 sensor causing the problem.


lhanddh
User

Aug 7, 2010, 10:27 AM

Post #20 of 35 (5812 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

Ok, im back. Thanks for all the advice. Truck is running alot better. Now it is flashing code 43 electric spark control. I have replced the electri spark control, the speed sensor, a compleat throtol body unit with all new sensers, oxgen sensor, computer,and all vacume hoses.still flahing same code. The truck rus good at an idel andgoing down the road but go between 25 and 45 mph and it starts surgen, or like loping and will stall, if you let your foot off the gass it goes back to ideling fine, or if you put your foot into it it smooths out and takes off like there is no problem. Just put on new plugs, wires, cap and roter. still same problem


(This post was edited by lhanddh on Aug 7, 2010, 5:00 PM)


lhanddh
User

Aug 14, 2010, 3:25 PM

Post #21 of 35 (5787 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

well, 7 days later and no replys i guess evryone is as stumped on this one as i am, well thanks anywayFrown


Tom Greenleaf
Ultimate Carjunky / Moderator


Aug 15, 2010, 7:09 AM

Post #22 of 35 (5547 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

Long thread and sorry if I missed it. At 250,000 miles the timing chain could easily be way over spec for lash. Short of just going in there to see try putting timing on a known like TDC turning crank bolt in one direction and stop. With dist cap off see how many degrees engine turns by hand at that bolt before rotor turns. More than 5 degrees is trouble.

When they are way off they can jump and go back. Usual initial symptoms are backfires, loss of power and staggered misfires and perhaps snap right out of that.

Hey - it's a guess when you've checked everything with a high mile engine this can be the kicker. May or may not show with other routine tests and codes aren't likely to help except those that can say random missfire perhaps.

If you know it's original it is junk - trust me. 99% of ones I have done were because I was close anyway for another reason like a water pump and vehicles with over 100k to be kept I just asked if they wanted the next item in as the labor was mostly done.

Just once I was shocked to remove an OE timing chain at over 100k that really was good. Nylon geared cam geared (OE one) so did it anyway as it not big bucks,

T
_________________________________________
Long retired now


Sidom
Veteran / Moderator


Aug 15, 2010, 8:05 PM

Post #23 of 35 (5538 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

As you know that code is for the electronic spark control. There is a problem with your knock sensor circuit. Basically when there is a knock the ESC sends a signal to the PCM and it retards the timing.... When the signal is there for too long the code is sets.

If I remember correctly the signal wire has 12v on it and the ESC pulls the voltage down when a knock is detected. These weren't the best sensors and anything could generate a signal.

So 1st off if there is any mechanical problem going on making a noise, that would need to addressed.... Tom already mentioned some....

After than you need to get a diagram for the circuit and check voltages and make sure the knock sensor can generate a signal....

I'm a little data challenged at the moment so I can't post anything but if you really need something, I might be able to get something from work....

I don't know what you have tool wise but a scanner & scope really makes checking this problem out A LOT easier.......


Just a quick thought..... A good short cut would be to get a diagram find the circuit that goes from the ESC to the PCM, disconnect both connecter & check it with an ohm meter to make sure it isn't open. Then find the circuit going from knock sensor to the ESC, make sure it isn't close to any plug wires......After that you need to start at square 1......






__________________________________________________________________________________________



lhanddh
User

Aug 15, 2010, 9:22 PM

Post #24 of 35 (5533 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

moter and trans was replaced about 6 years ago,has about 60,000 miles about 3 monthes ago replaced the distributor. Is it posibale it could still be in the timing chain. I will check like you said, thanks for the help.


lhanddh
User

Aug 15, 2010, 9:25 PM

Post #25 of 35 (5532 views)
Shortcut
Re: 89 chevy truck staling [In reply to] Sign In

I will try these and get back to you and let you know how it turns out, and thanks again
cant find where the knock sensor is, book has it in front of the starter, there is nothing there.


(This post was edited by lhanddh on Aug 19, 2010, 9:28 PM)




89 chevy truck staling


First page Previous page 1 2 Next page Last page  View All Email This Post
 
 






Latest Forum Post
As the title says, i have a problem with the window. The motor works fine but th...
Hello to all. I got a peugeot 205 1.8d that has a dangerous problem in the stee...
Bought this 1999 burb a couple months ago with a severe rap (it seemed like uppe...
1989 Chevy c1500 218xxx with a 5.7 TBI the day before it stopped running it ran ...
Hi. I need a bit of advice on a 2007 B4000. I like the truck with a couple of ex...
Hi, I have rebuilt engine due to cracked head, new pistons etc, put all back tog...

Feed Button


Used Car Search
Used Car Price Ranges:
Under $5,000
$20,000
$35,000

$10,000
$25,000
$40,000
$15,000
$30,000
$45,000
Over $45,000
Search used Cars By Manufacturers:
Used Acura
Used Audi
Used BMW
Used Buick
Used Cadillac
Used Chevrolet
Used Chrysler
Used Dodge
Used FIAT
Used Ford
Used GMC

Used Honda
Used Hyundai
Used Infiniti
Used Jaguar
Used Jeep
Used Kia
Used Land Rover
Used Lexus
Used Lincoln
Used Mazda
Used Mercedes-Benz

Used MINI
Used Mitsubishi
Used Nissan
Used Porsche
Used Saab
Used Scion
Used Subaru
Used Suzuki
Used Toyota
Used Volkswagon
Used Volvo
2010 Honda Civic
$15,770
2004 Jeep
$8,991
2012 Mustang
$22,990
1997 Honda Cr-V
$4,490
2010 Toyota Prius
$17,496
2010 BMW 328
$26,980




Automotive Forum Categories
Automotive Repair
Auto Body Repair and Refinishing
AC Auto Repair Help Forum
Automotive Wiring and Electrical

Auto Insurance and Car Financing
Automotive World
Brake Systems
Car Stereo Repair Advice
Car Troubleshooting
Engine and Car Noises
Engine Fault Codes
Engine Troubleshooting
Exhaust System Repair

Steering and Suspension
Tricks of the Trade
General Discussions
Car Shows and Events
The Bargin Bin
Motor Vehicle Inspection
Car Care Tips
Traffic Ticket Help
Car Racing

Gasoline, Motor Oils, Concept Cars
Remote Control Cars and Vehicles
Truck Repair
Truck Repair Advice


Truck Engine Repair
Truck Suspension Repair
Motorcycle Repair
Motorcycle and ATV Repairs

Motorcycle Body Repair
Motorcycle Clutch Repair
Motorcycle Engine Repair
Motorcycle Seat Repair
Car Forum Posts - Sitemap


Search for (options) Privacy