Question about 1990 GMC Sierra

6 Answers

No power i've just got this pickup.. and it's gutless.. the only thing is.. I've changed the fuel filter.. spark plugs.. and done a compression test 1. 130psi 3. 130psi 5. 130psi 7. 100psi 2. 100psi 4. 100psi 6. 115psi 8. 115psi compression seems okay.. i put the crank on tdc #1 and looked at distributor.. it's pointing at #1 cylinder. and checked the firing order.. with engine running.. when you rev it up.. it sputters all most backfire through the throttle body.. i'm lost need help... only thing i can think is maybe the cam out of time..

Posted by on

  • 3 more comments 
  • cheddar_bob4 Nov 10, 2008

    i've just got this pickup.. and it's gutless.. the only thing is..
    I've changed the fuel filter.. spark plugs.. and done a compression test
    1. 130psi 3. 130psi 5. 130psi 7. 100psi
    2. 100psi 4. 100psi 6. 115psi 8. 115psi

    compression seems okay..
    i put the crank on tdc #1 and looked at distributor.. it's pointing at #1 cylinder. and checked the firing order..

    with engine running.. when you rev it up.. it sputters all most backfire through the throttle body.. i'm lost need help... only thing i can think is
    maybe the cam out of time.. or the throttle position sensor.. any ideas

    also checked out all the fuses..

  • cheddar_bob4 Nov 10, 2008

    i've just got this pickup.. and it's gutless.. the only thing is..
    I've changed the fuel filter.. spark plugs.. and done a compression test
    1. 130psi 3. 130psi 5. 130psi 7. 100psi
    2. 100psi 4. 100psi 6. 115psi 8. 115psi

    compression seems okay..
    i put the crank on tdc #1 and looked at distributor.. it's pointing at #1 cylinder. and checked the firing order..

    with engine running.. when you rev it up.. it sputters all most backfire through the throttle body.. i'm lost need help... only thing i can think is
    maybe the cam out of time.. or the throttle position sensor.. any ideas

    also checked out all the fuses..

  • cheddar_bob4 Nov 10, 2008

    i've just got this pickup..it's gutless and it mildly over heats... if radiator cap is loose you can drive it all over the only thing is..
    I've changed the fuel filter.. spark plugs.. and done a compression test
    1. 130psi 3. 130psi 5. 130psi 7. 100psi
    2. 100psi 4. 100psi 6. 115psi 8. 115psi

    compression seems okay..
    i put the crank on tdc #1 and looked at distributor.. it's pointing at #1 cylinder. and checked the firing order..

    with engine running.. when you rev it up.. it sputters all most backfire through the throttle body.. i'm lost need help... only thing i can think is
    maybe the cam out of time.. or the throttle position sensor.. any ideas

    also checked out all the fuses..

  • cheddar_bob4 Nov 10, 2008

    i've just got this pickup..it's gutless and it mildly over heats... if radiator cap is loose you can drive it all over.. i just want to get it runnin right then i'll wory about the heating problem the only thing is..
    I've changed the fuel filter.. spark plugs.. and done a compression test
    1. 130psi 3. 130psi 5. 130psi 7. 100psi
    2. 100psi 4. 100psi 6. 115psi 8. 115psi

    compression seems okay..
    i put the crank on tdc #1 and looked at distributor.. it's pointing at #1 cylinder. and checked the firing order..

    with engine running.. when you rev it up.. it sputters all most backfire through the throttle body.. i'm lost need help... only thing i can think is
    maybe the cam out of time.. or the throttle position sensor.. any ideas

    also checked out all the fuses..

  • cheddar_bob4 Nov 11, 2008

    i've just got this pickup..it's gutless and it mildly over heats... if radiator cap is loose you can drive it all over the only thing is..
    I've changed the fuel filter.. spark plugs.. and done a compression test
    1. 130psi 3. 130psi 5. 130psi 7. 100psi
    2. 100psi 4. 100psi 6. 115psi 8. 115psi

    compression seems okay..
    i put the crank on tdc #1 and looked at distributor.. it's pointing at #1 cylinder. and checked the firing order..

    with engine running.. when you rev it up.. it sputters all most backfire through the throttle body.. i'm lost need help... only thing i can think is
    maybe the cam out of time.. or the throttle position sensor.. any ideas

    also checked out all the fuses..

    I've had many solutions... and I thank you guys for tryin to help...
    it actually turned out to be.. the diode under passenger side dash.. u are supposed to remove to set the timing.. it must have had a bad connection or somthing.. anyhow engine now has restored power and no longer overheats... maybe another tip for ya guys.. thanks again

×

6 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 685 Answers

Check ur engine

Posted on Nov 11, 2008


  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Master
  • 1,861 Answers

Here is my observation, and my solution: Your compression is NOT ok. Additionally, anytime that there is sputtering or backfiring thru the throttle body indicates a timing chain or timing belt issue, whichever you have. This would also explain the poor compression readings. On your engine, they should all match, and be at least 150 psi; +/- 3-5 psi. Plus, if the timing is off, your vehicle will not have any power,as you state. Best advice: Get the timing chain/belt inspected to see if it has jumped time. If so, replace it.

Posted on Nov 10, 2008

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 1,952 Answers

If you have fouled sparkplugs then the car will hesitate when you accelerate, seeming to 'miss' a step or two. if it's a clogged throttle body, the car will just act sluggish, gas mileage will go down and the accelerator might stick a bit when you try to step on it.

Posted on Nov 10, 2008

  • mohammed marika thambi
    mohammed marika thambi Nov 11, 2008

    how it's
    supposed to go. The diodes keep one side from back-feeding though the hazard
    connection into the other side when you want only right or left turn signal.




×

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Brigadier General:

    An expert that has over 10,000 points.

  • Master
  • 6,966 Answers

Hi,

Initially, would suspect:

  • timing off;
  • stale/contaminated fuel;
  • sparkplug wire leak;
  • clogged injectors.
Have you tried flushing the fuel system and/or using injector cleaner?

Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information. Good luck and kind regards. Thank you for using FixYa.

Posted on Nov 10, 2008

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Scholar:

    An expert who has written 20 answers of more than 400 characters.

    New Friend:

    An expert that has 1 follower.

  • Expert
  • 51 Answers

1 Inspect Ignition Timing Incorrectly adjusted engine timing. no power - grey_line.gif 2 Inspect Timing Chain Slipped or worn timing chain. 3 Inspect Timing Belt Slipped or broken timing belt. grey_line.gif 4 Inspect Point Set Burned, worn or incorrectly set ignition points. grey_line.gif 5 Inspect Firing Order Spark plug wire(s) not connected in correct firing order sequence grey_line.gif 6 Inspect Distributor Worn, loose or incorrectly adjusted distributor. grey_line.gif 7 Inspect Crankshaft Position Sensor Damaged or faulty crankshaft position sensor or circuit. no power - grey_line.gifttp://i.fixya.net/uploads/images/grey_line.gif" alt="grey_line.gif" class="h_mi" /> 8 Inspect Crankshaft Timing Gear Worn timingno power - grey_line.gifgrey_line.gif 9 Inspect Spark Plug Wire Loom - Performance Improperly adjusted or worn/malfuncno power - grey_line.gifretor. grey_line.gif 10 Inspect Camshaft Position Sensor A Damaged or faulty camshaft position sensor will transmit incorrect ignition no power - grey_line.gifvery information. grey_line.gif 11 Inspect Camshaft Interrupter-Magnet A Damaged or faulty camshaft interrupter-magnet will cause the camshaft position sensor to receive and transmit incorrecno power - grey_line.gifd fuel delivery information. grey_line.gif 12 Inspect Camshaft Timing Gear Worn or broken camshaft gears may affect propno power - grey_line.gife, compression, combustion and exhaust. grey_line.gif 1no power - grey_line.gifDistributor Cap Loose or cracked distributor cap grey_line.gif 14 Inspno power - grey_line.gifacuum) Misrouted, damaged, loose, or clogged vacuum hose(s) grey_line.gif 15 Inspect Point Dwell Point dwell not within specified range 16 Inspect Point Gap Incorrect point gap setting. 17 Inspect Timing Set Slipped timing chain or worn timing gear(s) grey_line.gif no power - clearpixel.gif It sounds like a timing problem I recomend taking it to your local garage and hooking it to a computer.clearpixel.gif

Posted on Nov 10, 2008

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Sergeant:

    An expert that has over 500 points.

    Novelist:

    An expert who has written 50 answers of more than 400 characters.

  • Expert
  • 196 Answers

Check out the fuse Left side and below the steering column. The cover has a finger pull, just pull out and down a little

Posted on Nov 10, 2008

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

6 Answers

When going up hills I lose momentum I changed the plugs,wires, and 02 sensor and it goes up to 3 rpms why isn't it fixed?


First check for any codes, then test vacuum with a good vac guage. When reving engine the vacuum should drop and then climb back up. Check for vacume leaks by spraying carb cleaner at any vacume hoses and intake areas but not at air filter.

then also check compression as well as look at spark plugs to see that they are all tan and no differences in any one. Go to YouTube and search for how to test engine with a vacuum gauge.

Most any problem with an engine can be diagnosed with a vacuums gauge but do use a second test method as you have learned replacing parts hoping to fix a problem is costly.

Mar 25, 2015 | 2001 Kia Sportage

2 Answers

Car turns over but won't start. Boyfriend checked the spark plugs , says vetting spark. It says he did a compression check to it. Starter is a year old, battery new, we replaced fuel pump 3 weeks ago...


A thumb is not test for compression as 10lb/sq " will blow your thumb off. Have a proper compression test done. Next although it is sparking the question to ask is it sparking at the right time and to the right cylinder. Pouring fuel into the cylinder is a waste of time as the air/fuel ratio will be too rich to ignite even if the spark was occurring on the compression stroke. So here are some simple steps to follow to get it going
Have a compression test done to determine if there is sufficient compression to ignite the mixture
2 check that the spark is occurring at the cylinder at the right time ( no 1 cylinder on timing mark on compression stroke.)
3 . If it is EFI engine then check that the injectors are actually squirting if carby engine check that the fuel is in the fuel bowl With engines you have to have a combination of 3 things for the engine to work They are compression -which you will be checking for--2 spark timing--- which you will be checking for and lastly 3 fuel into the cylinder at the right time ==which you will be checking for
you only have to be missing one of these and you had best take it to a professional mechanic to get it started.

Jul 13, 2014 | Cars & Trucks

1 Answer

Have a 2002, 2.5 Subaru Outback Automatic. Has new Platinum tipped spark plugs, air filter, clean injectors etc but car is quite gutless especially going up hill and every time I try to accelerate the...


could you have a restriction in exhaust system-the catalytic converter-otherwise what are your compression numbers for each cylinder-another easy thing to do would be to install a new fuel filter-cheers Denny

Nov 02, 2013 | Subaru Cars & Trucks

1 Answer

I have cleaned all injectors and have two cylinders that dont seem to be fireing. i've pulled plug wires and tested with another plug and they have fire. I even placed two good injectors where the


I'm assuming you have done a compression test and all cylinders have equal compression, right ?
If you think it is a fuel problem, you would check for power and a ground signal at each injector before replacing them.

Apr 09, 2013 | 1994 Jeep Grand Cherokee

1 Answer

Have a 99 s10 with multiple cylinder misfire code. I've changed coil packs, ignition module(used) plugs, fuel filter, timing chain tensioner. Very little power. Any other suggestions as to what can...


Are your spark plugs oily,if so then your piston rings are bad.A compression test will tell you that these cylinder misfires will be low in compression,timing could be off.

Oct 23, 2012 | Cars & Trucks

1 Answer

1.4 16 V 2000 Zetec engine makes unusual noises and vibrations and it has less power than normally. Spark plugs are ok. Engine light popped up at first interminently, then permanently.


First of all, check the Oxygen sensor, coil, and all spark plug wires. check the air and fuel filters. Failing this, it might be time to look at having a compression test, and a fuel PSI test done.

Jun 27, 2011 | Ford Focus Cars & Trucks

1 Answer

My 1992 Ford Tempo won't start. It acts like it wants to start by turning over but there is no catch to fire it up. So far the alternator, harmonic balancer, fuel pump, plugs,distributor and filters...


...the harmonic balancer was replaced? I hope that was not in relation to your vehicle not starting - if it was, that was a waste of money. The first three things to check for are fuel, air, and spark.
You need to test if the spark is making it to the end of the spark plug - can be done by removing a plug and placing it in the wire - and setting it near something that it can arc to. Just don't zap yourself.
Next, check for fuel pressure.
Check for a clogged air intake system or dirty air filter.

After than you'd check for compression - by putting a compression gauge in to a spark plug port. If the compression is low or off by 25% in one cyl from the different ones, this is an issue.

May 09, 2011 | 1992 Ford Tempo

2 Answers

Car was slowly running worse and worse and now will not start .


2 things will cause this issue. a plugged fuel filter or plugged catalytic convertor. im assuming youre talking about a loss in power over a relatively short amount of time? check your filter first by removing it from the frame and once drained, wipe the inlet side clean and blow through. if you look like a chipmunk, its plugged. they should blow through with minimal resistance. if that is good the next step is to find a TRUSTED exhaust shop in the area and have them check the "cat".

Nov 04, 2009 | 1994 Pontiac Sunbird

2 Answers

My Nissan Pickup is losing power


If you take the vehicle to a local shop, you can get a mechanic to do a compression check on each one of your cyllinders. This will tell you if your engine is holding pressure. If that checks out, it would have to be a fuel problem, (injectors, pump, filter, or clogged line) or maybe spend the couple bucks, and buy yourself a new MAF (mass airflow sensor) it may be the problem, but if not, it always helps to change.

Jan 30, 2009 | 1984 Nissan Pickup

4 Answers

1998 ford explorer turn over but wont start.


Under the hood there is a grey box on the right side open it and then you will see some plugs there is a 3prong plug take it out and get it replaced it will cost about $4.00 or no more then $10.00 or so and it should start after that I had the same problem.
Nikki2913

Jul 08, 2008 | 1996 Ford Explorer

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

170 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts

yadayada
yadayada

Level 3 Expert

60960 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21949 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6812 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...