Question about 1985 Chevrolet C1500

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Popping sound in carb when i throttle it up

I have changed the distributor and checked the timing with the advance off its in time at 4 btdc no vaccum leaks at all did the wd-40 test fuel pressure is low but just put a new pump on it even with the electric pump on it puttin out 7 psi it still pops gas back up the carb on the one side not both ??????????????

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  • Mark Paxton
    Mark Paxton Dec 30, 2008

    i have been told that i may have one lobe gone south but keep in mind that my truck has less than 100,000 miles on it  96 and change to be exact im still at a loss i how ever do have the vaccum advance hooked up to constant vaccum will that have any effect on it 

  • Mark Paxton
    Mark Paxton Dec 30, 2008

    im going to check it out is there any way other than pulling the valve coverof and taking a oil bath i already pulled the plug wires and no change with it running any other advice im open ???????

  • Mark Paxton
    Mark Paxton Dec 30, 2008

    yes i think it is number 5 cylinder but thats just a guess i have had an exhaust leak on the right side for some time i did fix it but the connection for the pipe and manifold is loose again



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Sounds like you may have a cam lobe gone flat

Posted on Dec 30, 2008

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  • TripleTauto
    TripleTauto Dec 30, 2008

    MILEAGE may not have anything to do with it i have seen them go with less mileage. the timing advance should not cause this although it should be hooked up to ported vacuum

  • TripleTauto
    TripleTauto Dec 30, 2008


  • TripleTauto
    TripleTauto Dec 31, 2008

    if you have a way of measuring the lift you can rotate engine manually and see if valves are opening it is probably going to be an exhaust valve not opening

  • TripleTauto
    TripleTauto Dec 31, 2008

    if you have a way of measuring the lift you can rotate engine manually and see if valves are opening it is probably going to be an exhaust valve not opening



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Hi guys I have a 1986 Toyota Landcruiser 3f motor petrol and am having troubles with timing the distributor my flywheel has two lines marked on it and one ball inlaid mark which one do I time it on?

the lines are probably 5 degrees and 10 degrees btdc
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How is ignition timing regulated? Car gets 99 BTDC on ignition timing and failed SMOG Test in CA. Listed as GROSS POLLUTER.

something wrong here
with 99 degrees btdc it will not run
have you got it on the correct plug lead
next the timing is regulated by centrifugal advance if electronic or points and by the crankshaft position sensor if ECM controlled ( some after market distributors that are used in place of points units have a small sensor in the distributor that can adjust the timing according to engine rpms, but it cannot make allowances for mixture and so they can advance the timing but not take into account anything else which sometimes results in detonation under certain throttle settings
so initial setting for most cars is 10-12 degrees btdc at idle and with engine rpms set up to 3000 rms it may advance to 25-30 degrees depending on the advance mechanisms
with ECM units the timing is controlled by the crank position sensor and is set to parameters according to engine rpms and air/fuel ratio settings but it still has a basic 10-12 degrees btdc on starting
to fail smog tests you probably do not have a working cat converter and other problems besides timing

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1995 nissan hardbody, replaced timing chain with new kit. Crank, cam sprockets woodruff keys at12 o'clock. Punch marks aligned with black timing chain links. Engine timed at 10 degree BTDC. -5, tdc, 5, 10,...

It starts up easy and idles good? And timing is at 10 BTDC? Sounds like you got it right then. I would check the fuel pressure at the fuel rail first. If fuel pressure is correct, maybe the throttle position sensor is bad?

Do you have vacuum advance on the distributor, or is it controlled by the ecu? If a vacuum advance device, maybe that is the problem. Beyond that, I don't know.

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How to set timing when replacing timing chain

I am not familiar with this car, but I think you get the timing from the crankshaft sensor, unless you still have a distributor.

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Hi 2.6 rodeo isuzi 1997 egine wont idle or rev out also slight back fire through inlet manifold have tryed to fix im a mechanic tried changing mass air flow sensor as check light was on when fitted

Hi Bruce, The reset of the engine check light should be incorporated into your diagnostic equipment. Erase Fault Codes should do the job for you. I think that the fuel pump pressure is low. It should be about double the reading you have. (3.8 bar or 55.2 lbs per sq in) Replace the pump and fuel filter. In addition take some water and check that the intake manifold is not leaking air, as that would cause the problem you're reporting. If anyone has taken the distributor out check the setting again and the HT lead positions. Regards John

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Pionts setting for 460 engain

don't forget when setting the timing on a 460 to pull off the vacuum advance hose from the distributor and block it off to prevent a vacuum leak , set the timing at 8 degrees BTDC, the points should be set at gap .017" the firing order is 1-5-4-2-6-3-7-8

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1983 nissan 280 zx car back fires when cold

Sounds like you could have an aux air regulator valve, that is not working when it will not work; there is no fast idle cold. Should be around 1500 rpm cold, the car will stall out and pop through the intake when bad. You have a digital volt meter to do some testing with to make sure the mass air flow is working correctly.

Also, c
heck the plugs for how they're burning, check the air filter for good flow, do a compression test and judge from there. Intake backfire is usually caused by running lean or improper timing.

For the 79 model zx, ignition timing was 10 degrees BTDC @ 700rpm
For 80 and up zx, non turbo - 8 degrees BTDC +- 2 degrees @ 700rpm
turbo - 20 degrees BTDC +- 3 degrees @ 700 rpm

Also done with distributor vacuum advance hose removed and plugged.
* BTDC = Before Top Dead Center
* + - = Plus or minus
Hope thos helps; keep us updated.

Aug 02, 2011 | 1983 Nissan 280ZX

1 Answer

1. How many degrees is the proper ignition timing for Toyota 4KU engine? 2. What is the rated bhp @ what rpm? 3. Max. Torque 4. Rated Fuel ratio per bhp.

Awesome little car! I'm not sure where they want the timing at idle but if you have an advance style timing light, bring the engine up to 3500 rpm and twist the distributor so that you see 40 degress btdc. and you'll be good to go. I'll dig up the idle specs later if you like and post them.

Feb 27, 2011 | 1983 Toyota Starlet

1 Answer

How do you time a toyota 4 runner 3.0?

22r-E, 3vz-E And 3f-E Engines

  1. Warm up the engine, then turn it OFF. Connect a timing light to the engine following the manufacturer_s instructions.
  2. Connect a tachometer to both battery terminals. Connect the tachometer probe to the IG-terminal in the check connector box. The check connector box is located next to the underhood fuse and relay box on trucks and 4Runner's; for Land Cruisers, the check connector box is on the firewall. Use the correct adapter to insure a tight fit on the terminal. Not all tachometers, particularly older ones are electrically compatible with this system. Read instructions for your unit before using.

Attach the tachometer as shown

3. Start the engine and run it at idle. Check the idle speed on the tachometer; adjust it to specification if necessary.

4. At the check connector, use a small jumper wire to short the connector at terminal T or TE1 and terminal E1, of the DLC1 as shown. Special service tool (SST) 09843-18020 or its equivalent can be used for this also.

Connect the SST or jumper wire to the TE1 and E1 terminals of the DLC1

This jumper will be used repeatedly during diagnostics in later sections. Take the time to make a proper jumper with correct terminals or probes. It's a valuable special tool for very low cost.
  1. Check the idle speed, then check the ignition timing. The 22R-E should read 5° BTDC, 3VZ-FE should read 10° BTDC and the 3F-E should read 7° BTDC. All of these readings are at idle.

On 3-FE engines, remove the rubber plug at the rear of the engine to view the timing mark

On other engines, the timing mark is visible on the crankshaft pulley

  1. Loosen the distributor pinch bolt just enough that the distributor can be turned. Aim the timing light at the marks on the crankshaft pulley (or the drive plate on 3F-E) and slowly turn the distributor until the correct timing mark aligns with the pointer. Tighten the distributor pinch bolt.
  2. Remove the jumper wire or special service tool (SST) from the DLC1.
  3. Check that the ignition timing advances. At idle the 22R-E should read 10°-14° BTDC, 3VZ-FE should read 8° BTDC, and the 3F-E should read 12° BTDC.
  4. Shut the engine OFF and remove the timing light and tachometer leads.

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2 Answers

My 88 Mustang GT boggs on me.

Sounds like the timing is off. When looking at the distributor cap right next to it should be 2 wires with a plug at the end of it. Unplug it and start the car then check your timing . Make sure you mark the crank 10 degrees BTDC. You can bump it to 14 degrees BTDC if you like to gain 10 extra hp. After timing is set turn off car plug spout back in to the 2 wire outlet.(You have to unplug the 2wires in order to time a 5.0 the 2 wires control vaccum)
BTDC-(Before Top Dead Center)

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