Whats wrong with my engine it misfires?

It will flow less, they have different flow rates on each one. I would replace them all the same that way they flow the same on the same cylinder, so yes I would replace them all, might be a good time to do it also while its apart

Hi there, you should check the fuel pressure while the truck is running, you may see it has low pressure when start and may correct itself a bit when the truck warms up. As for the codes; you probably fixed the issues with the MAF with a new sensor, but I would go after fuel pressure at this point.

If it is low you could just have a clogged fuel filter. Not sure if you have ever changed it or not, but you do have a lot of mileage on the truck, really a fuel filter should be changed at least every 30,000 miles, it can wear down your fuel pump. But check the pressure first and go from there. You may also take the filter off and see if you can blow any air through it, that is an easy check. Fuel filters are relatively inexpensive to change.

You may have some pressure, just not within spec, since you have replaced so many of the ignition parts already, defiantly check the fuel pressure. Also, are any of the codes returning after the other fixes?

Hello JAKE4049,

Here is a link to an article from this site with step by step instructions and pictures explaining the process of checking the fuel system pressure, regulator and fuel pump in less than fifteen minutes:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

If you need further assistance please come back to the site we are always happy to help.

Kindest regards,
Renee
Admin

That sensor runs off of 12 volts. Was the fuel pressure okay? It sounds like the PCM could be bad. Can you disconnected the battery and then reconnect it to see if that makes a difference?

Also, I have seen the EGR valve sensor melt and cause this issue as well. FYI

Please let us know what you find.

Cheers, Ken

I would test the ignition control module and the ignition pick-up assembly. The description sounds like it is losing spark on both coil assemblies at the same time. Those items control that.

Welcome to 2CarPros.

First, if you notice a misfire, the light should be on. Confirm it is working when you first turn the key on. It should turn off after a few seconds. With that in mind, I still need you to check for trouble codes. All you need to do it is a test light. Follow the directions in this link:

https://www.2carpros.com/articles/ford-lincoln-mercury-obd1-1995-and-earlier-diagnostic-trouble-code-definition-and-retrieval

If no codes are found, it could be many possible issues. I am going to provide links on the different things to check.

Next, if you question that a possible head gasket can be an issue, here is a link that shows how to check:

https://www.2carpros.com/articles/head-gasket-blown-test

Next, you may have a plugged catalytic converter. Here is a link that shows how to check that:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Also, a timing issue can be the cause which would result in low compression and ignition timing issues. With that, I would recommend testing engine compression.

https://www.2carpros.com/articles/how-to-test-engine-compression

As far as the tiny leak, make sure it isn't allowing unmetered air to enter the engine. That will cause at least a rough idle.

Now, in addition to all of this, I am really questioning if the timing belt has jumped. Here are directions for installing the timing belt. I'm adding them in case you want to check to make sure timing marks are correct. The attached pictures correlate with these directions.

INSTALLATION
Special Service Tool Required:
Camshaft Belt Tension Adjusting Tool T74P-6254-A
Synchronizer Positioner T93P-12200-A

picture 1

1. Remove one spark plug from each cylinder.
2. If not done:
a. Loosen tensioner adjusting bolt.
b. Using Camshaft Belt Tension Adjusting Tool, PRY tensioner CLOCKWISE against spring tension as far as possible.
c. Tighten adjusting bolt to hold tensioner in RELEASED position.
3. Align crankshaft so number one piston is at Top Dead Center (TDC) as indicated by timing mark.

picture 2

4. Line up the camshaft sprocket timing mark with the inner timing belt cover timing mark, so that the key is pointing DOWN.

NOTE: On 49-State, and all Automatic Transmission vehicles, it is not necessary to align auxiliary shaft sprocket.

5. If vehicle is California Emissions Certified with a Manual Transmission:
a. Install Synchronizer Positioner into synchronizer.
b. ROTATE auxiliary shaft sprocket until the synchronizer shutter is against the stop, and the notch of the tool engages the notch of the synchronizer bowl.
6. Install timing belt over crankshaft sprocket. Then, proceeding COUNTER-CLOCKWISE, over auxiliary shaft sprocket and camshaft sprocket.
7. Loosen tensioner adjusting bolt allowing tensioner pulley to press against timing belt.
8. Remove tool from synchronizer.

NOTE: When performing the following step, DO NOT ROTATE crankshaft COUNTER-CLOCKWISE as timing belt may jump a cog, putting camshaft or auxiliary shaft out of time.

9. ROTATE crankshaft two revolutions CLOCKWISE.
10. Bring crankshaft slowly, without stopping, to number one cylinder firing position (keyway directly UP).
11. Recheck timing mark alignment. Repeat steps if timing marks are no longer properly aligned.
12. ROTATE tensioner assembly against bolt with torque wrench up to 41-45 N.m (30-33 ft-lb) and tighten adjusting bolt.
13. Tighten adjusting bolt to 35-45 N-m (26-33 ft-lb).
14. Tighten spring pivot bolt to 40-55 N.m (30-40 ft-lb).
15. Install the crankshaft belt guide.
16. Install the crankshaft position sensor onto the dowel pin and tighten the two longer bolts to 8-12 N.m (6-9 ft-lb).
17. Adjust crankshaft position sensor air gap.
18. Install outer timing belt cover.
19. Install spark plugs.

Let me know if any of this helps or if you have other questions.

Take care,
Joe