Question about 1994 Ford Thunderbird

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I have 94 T-bird with 4.6 v8, engine wont run, changed plugs, wires, good fuel pressure, injector pulse, good fire, no obvious vacuum leaks. Spins over good, starts, but wont run. Any idea what to try next.

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  • taylor4140 Mar 13, 2009

    haven't checked compression- it does try to run usually the first time you turn the key, but it stops and just turns over after the initial start.
    I checked each plug wire for fire good, checked injectors spraying good, pulled the new plugs out and checked for fouling, they were ok but did have gas on them. No cough or sput.


  • taylor4140 Mar 25, 2009

    Compression checked good. 1-165, 2-175, 3-178, 4-177, 5-180, 6-180
    7-168, 8-178


  • taylor4140 Mar 25, 2009

    35 psi. yes, if i hold the pedal to the floor it will try to start and some times runs for 3 to 5 seconds.

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  • 4,669 Answers

All I can think of is to check the compression. Did you replace the plugs and wires because it wouldn't run? Does it even try? Does it cough and sput?

Posted on Mar 12, 2009

  • 1 more comment 
  • Clint Smock
    Clint Smock Mar 13, 2009

    Do the compression test.

  • Clint Smock
    Clint Smock Mar 25, 2009

    What do you have for fuel pressure? Does it try if you hold the accelerator all the way to the floor?

  • Clint Smock
    Clint Smock Mar 25, 2009

    Is there any way you can unhook the exhaust from the manifolds to test for plugged exhaust?

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1998 nissan frontier xe 4 cyl auto misfire cyl #2 engine vibrates like a bad sparkplug when driving


To review - - do you know for a fact the distributor is firing that cylinder? And do you have power and a ground pulse for that injector ?
You say no vac leak, but have you done a compression test on all cylinders ? Is it possible the egr valve is leaking and affecting that cylinder ?

Feb 20, 2014 | Nissan Cars & Trucks

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Misfire from cylinder 1 and fuel injection stuck open


One problem will cause another in this case. You can try to just change the fuel injector in the number 1 cylinder and see if the misfire straightens out.

You can use a test light to see if there is a pulse in the wire harness to the number 1 injector. Or there are plug-in lights which attach to the head of the injector harness to show firing of the injectors. Either way, th pulse should be a timed intermittent burst to that 1 cylinder when it is time to fire, just a spark goes to a sparkplug in intermittent bursts.

The crankshaft or camshaft sensor should send divided, pulsed signals to open the injector for fuel release. If the injector is jammed so that it does not go back to its seated position, you will get excessive fuel inside the engine when it is off. The fuel will bleed down into the crankcase and dilute the oil over time. This ruins an engine.

The fuel system normally remains pressurized and when the engine is turned off; the fuel will leak into the cylinder that is not shut. You may have to change the sparkplug as it can be gas-fouled by now. An oil change would be a good idea after you change the injector.

May 07, 2012 | 2004 Pontiac Grand Prix

1 Answer

Have 94 grand dam change fuel pump change presure regulater and relay pump stays runnig and car wont start


If by cranking you mean the engine starts then you are having fuel issues. If the car starts with starting fluid then you either don't have fuel pressure or the injectors are not opening. After starting with starting fluid does it continue to run until you shut it off or does it shut off on its own?

Either way you will need to install a fuel pressure gauge to make sure you have enough fuel pressure. If you do have fuel pressure then you will need to make sure the injectors are firing. There is a tool available called a noid light or injector pulse light. You will need to unplug one of the injectors and plug this tester into the connector. If the light flashes while cranking then the injector is being companded to fire. If the light does not flash then you either have a bad engine computer or a control module. More than likely it is the control module. The control module uses the input from the crankshaft position sensor to fire the coil and the injectors the module may be loosing the signal for the injector.

Hope this helps; also keep in mind that your feedback is important and I'll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using Fixya, and have a nice day.

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1 Answer

My car wont start, why


If it cranks normally, it is obviously not the starter relay; if it were the relay the starter would not operate. To begin with, when the vehicle is not starting you are going to have to determine whether it is losing spark, fuel pressure, fuel injector pulse, or some combination of these things.

You can check for spark by removing the coil assembly, plugging 4 known good spark plugs into the plug connectors and laying the plugs agaiinst the metal engine. Then have someone crank the engine over while you watch under the hood to see if the plug is firing.

To check for fuel pressure, you will need a fuel pressure gauge, connecting the fuel pressure gauge to the fuel rail test port, you can measure the pressure in the fuel system when the problem is occurring.

To check for injector pulse, you will need a logic probe or a noid light to check for injector signal (fuel pulse) at the injector electrical connector.

In order to begin diagnosis, you need to check these three things to determine what system the fault is in. Once this is determined, pinpoint testing down to the component level can be performed.

Hope this helps; also keep in mind that your feedback is important and I'll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using Fixya, and have a nice day.

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1 Answer

Hi, i have a 1993 ford f-150 4.9 the truck starts if runs very rich i have checked fuel pressure checked ok ive check spark getting a strong spark ive check for injector pulse and no problems the truck...


Hi,
I think you are on the right track. With the engine off remove the vacuum hose from the fuel pressure regulator and see if there is fuel in the vacuum hose or fuel is leaking from the fuel pressure regulator vacuum nipple,if so replace the regulator,check to make sure that the engine oil is not contaminated by fuel if so,change the oil and filter. Good Luck!

Sep 17, 2010 | Ford F-150 Cars & Trucks

1 Answer

Started ran for awhile then died an wont start


Start with the simple and replace your fuel filter, a dirty filter can cause your engine from starting. At worst, your fuel pump has failed and will need to be replaced. Before replacing the fuel pump, inspect all the fuses and wire leads from the fuel pump harness. Note: that the ground wire is separately grounded at the frame, so inspect that for any damage due to corrosion.

You need 3 things.
Compression
Good hot blue spark to all plugs.
Good gasoline and proper fuel pressure. 63-64 lbs.
If you have all 3 then move on to injector pulse to all injectors. I think each injector is on a seperate driver on that one. Check for pulse to all of them.

You may be weak on fuel pressure, even a couple of lbs low on a cold start will cause a no start. Double check cold start cranking fuel pressure. If under 63-62 lbs you have problems. One test is to give it a squirt of carb cleaner not starting fluid. If it starts then you have a fuel pressure problem.
Run the full fuel pressure test, here is the guide lines on testing.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure. Later V6 and V8 gm engines should have 60-66 fuel pressure.
* Cold start should be 64-65 lbs of pressure. If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
* Engine running should be 60-66 lbs pressure depending on engine load.
* Full pressure with return pinched off should be 75-85 or more. and if it has a fast leak down after shut off you have a leak.

The 75-85 is only a check on the capable full pressure of fuel pump. If you can not find the rubber return line check full pressure by plugging return line or just or the true full pressure can be taken direct at the end fuel filter.

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2 Answers

1997 chevy blazer getting fuel and spark but not starting, only backfiring through carb.


You need 3 things.
Compression
Good hot blue spark to all plugs.
Good gasoline and proper fuel pressure. 63-64 lbs.
If you have all 3 then move on to injector pulse to all injectors.
I think each injector is on a separate driver on that one.
Check for pulse to all of them.

You may be weak on fuel pressure . even a couple of lbs low on a cold start will cause a no start.
Double check cold start cranking fuel pressure. If under 63-62 lbs you have problems.
one test is to give it a squirt of carb cleaner not starting fluid. If it starts then you have a fuel pressure problem.
Run the full fuel pressure test and post back pressures.
Here is the guide lines on testing.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel. Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.


The 75-85 is only a check on the capable full pressure of fuel pump.
If you can not find the rubber return line check full pressure by plugging return line or just or the true full pressure can be taken direct at the end fuel filter.
What are the pressure readings that you have when done.
What are your cold start pressure readings?
Post back what you have. Good luck

Dec 24, 2009 | 1997 Chevrolet Blazer

1 Answer

99 Tahoe engine cranks, wont start


You need 3 things.
Compression
Good hot blue spark to all plugs.
Good gasoline and proper fuel pressure. 63-64 lbs.
If you have all 3 then move on to injector pulse to all injectors.
I think each injector is on a separate driver on that one.
Check for pulse to all of them.

You may be weak on fuel pressure . even a couple of lbs low on a cold start will cause a no start.
Double check cold start cranking fuel pressure. If under 63-62 lbs you have problems.
one test is to give it a squirt of carb cleaner not starting fluid. If it starts then you have a fuel pressure problem.
Run the full fuel pressure test and post back pressures.
Here is the guide lines on testing.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.


The 75-85 is only a check on the capable full pressure of fuel pump.
If you can not find the rubber return line check full pressure by plugging return line or just or the true full pressure can be taken direct at the end fuel filter.
What are the pressure readings that you have done.
What are your cold start pressure readings?
Post back what you have.


The other thing to that is common is the (ICM) under the distributor cap. There is a breather screen on the bottom of the distributor that get's clogged with dirt causing condensation promoting corrosion, this was gm TSB for replacing the cap and rotor to make sure it's clean.

Good luck and hope this helps. Merry Xmas.

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3 Answers

99 dodge caravan #4 cylinder misfires, i replaced spark plug wires and spark plugs. Scanner showed #4 still misfiring, could this be the coil?


It could very well be a bad coil pack,or you have low compression in that cylinder.If the compression is good then go with the coil pack,if not you may need a head gasket or an intake manifold gasket.

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1 Answer

Ok i had a p0302 and then i changed plug wires coil packs the icm injectors camshaft sensor and now i can a p0301 code.. and when i clear the code it will come back with the same code or else a p0300.. im...


1. Freeze Powertrain Control Module (PCM) and see if the problem can be duplicated.

2. Wiggle tug test wiring for #2 injector.

3. Scope the #2 injector for a glitch when the misfire happens. 1. Test for the Exhaust Gas Recirculation (EGR)/coolant adapter gasket leaking EGR gases past the gasket.

2. Connect a vacuum pump to the MAP sensor, block the vacuum source, reset fuel trims, start the engine and add typical vacuum to the MAP sensor and check operation.

3. Test the spark output with 2 High Energy Ignition (HEI) testers, at 25 KV air gap each, at the spark plug wires to ground at wires 2 and 3, then 1 and 4 at cranking speed and engine running.

4. Test the fuel injector pulse width at the injectors compared to the scanner data.

5. Disconnect the O2 sensor, reset the fuel trims, test the system operation in open loop, test injector pulse width. Compare to the closed loop operation injector pulse width and engine operation.

6. Test the Powertrain Control Module (PCM) powers and grounds during the problem.

Oct 13, 2009 | 1996 Chevrolet Cavalier

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