88 2.9L Misfireing/backfireing issue

[88 XLT Ranger]

The rain finaly stopped

I got the computer out took the cover off inspected it real good under a bright light. I see nothing wrong with it all looks good no damage or discoloration. I put it back in and changed the O2 sensor and the MAP sensor. I started it running crappy popping shaking it wont idle high than come down like it should. It starts and goes to 800rpm's trying to die I let it run a bit than shut it off tried to re-start it wouldn't I had to give it a little gas as it was trying to start than it would fire up. I let it warm up for 10 min it started clearing up running better. I took it for a test drive ran great up to 65mph started up the grade it started loosing power down to 35mph than popping again running like cap

My Ignition module on the Dist I pulled up on the wires at the connector it shut off. I notice as I move the wires the connector itself moves up and down its not tight. The snap clip on the connector is over the Module bump like it should. As soon as I got home I lifted the wires both times it killed the engine. How do you fix this issue could this be the popping as well? I still don't know why it wont idle high than come down on start up

 

[bronco2fan]

Before I put the duraspark on my 2.8 I had an issue with the tfi too. I checked all the wiring for cracking and bare wire. Didn't find any. But if I pulled on it , it would stall. Wound up putting a zip tie on the plug to seat it and the problem was gone. Just saying, whatever works.

Sent from my Alcatel9007T using Tapatalk

 

[Mark_88]

Well, you did mention this quite a while ago and it wouldn't surprise me at all if this was the root of your problem...unfortunately, it could be just one of a few possible problems that can crop up simultaneously but, as someone on here says regularly (I think it's RonD)..."lets get the obvious stuff out of the way first..." or something to that effect.

I would try to do what bronco2fan did to see if that helps...all it takes sometimes is a simple fix...

I had problems with my distributor on the 88 and it turned out to be a frazzled ground wire inside the distributor (2.0 different config) and it required a new distributor to fix so many mysterious problems...

But don't go out and buy one if a zip tie will fix it...maybe once you find that is the problem a new harness or distributor or whatever new parts will be in order...

 

[88 XLT Ranger]

Well, you did mention this quite a while ago and it wouldn't surprise me at all if this was the root of your problem...unfortunately, it could be just one of a few possible problems that can crop up simultaneously but, as someone on here says regularly (I think it's RonD)..."lets get the obvious stuff out of the way first..." or something to that effect.

I would try to do what bronco2fan did to see if that helps...all it takes sometimes is a simple fix...

I had problems with my distributor on the 88 and it turned out to be a frazzled ground wire inside the distributor (2.0 different config) and it required a new distributor to fix so many mysterious problems...

But don't go out and buy one if a zip tie will fix it...maybe once you find that is the problem a new harness or distributor or whatever new parts will be in order...

Thank Mark & bronco2fan

I will get some Zip Ties tonight see if that helps getting the connector tight. All the wires look good from the connector. Maybe I should pull the Dist cap look inside it as well? I think if it was an issue it would be doing all the time missing/popping

 

[Mark_88]

Thank Mark & bronco2fan

I will get some Zip Ties tonight see if that helps getting the connector tight. All the wires look good from the connector. Maybe I should pull the Dist cap look inside it as well? I think if it was an issue it would be doing all the time missing/popping

Not necessarily. I've had things that did similar and it was never consistent. I once had a wire harness from the ignition to the starter relay that was holding on by a single thread of wire...and I probably mentioned this before...but it would work fine until an connection further up the wire got jangled and broke the connection. Replacing the wire should have fixed it but...as it turned out...it was the connection further up the wire that was the root cause.

But you've already proven this to be a problem just by stalling the engine by moving the wires...so it could be part of another issue or a completely different issue...only thing to do is fix the one you see and go from there...

 

[88 XLT Ranger]

Not necessarily. I've had things that did similar and it was never consistent. I once had a wire harness from the ignition to the starter relay that was holding on by a single thread of wire...and I probably mentioned this before...but it would work fine until an connection further up the wire got jangled and broke the connection. Replacing the wire should have fixed it but...as it turned out...it was the connection further up the wire that was the root cause.

But you've already proven this to be a problem just by stalling the engine by moving the wires...so it could be part of another issue or a completely different issue...only thing to do is fix the one you see and go from there...

"Thanks again for the help all of you"

Well that didn't fix the popping/missing issue the connector is tight. It don't stall anymore moving the wires on the connector and harness. This runs truck runs bogging up to 25mph but once you give it more throttle it starts popping /missing. I wonder disconnecting the O2 sensor might help? or is that bad on the computer? maybe its getting to much fuel fouling the plugs. The plugs look good I can't see any issues there

 

[Spott]

Disconnecting the O2 sensor is a valid test.

If the computer can't read the value of the O2 sensor, it will go into "Open Loop" mode and calculate fuel injection information from the MAP, throttle position, and RPM, based on pre-calculated tables stored internally. This is the way it runs when first started, before the O2 sensor warms up. The engine will run slightly rich, but should otherwise work well.

If you disconnect the O2 sensor and the misfire goes away, then you've got a bad O2 sensor, or associated wiring or connectors. If you disconnect the O2 sensor and the misfire becomes continuous, then the problem is associated with "Open Loop" operation, which will narrow down the scope of the search. If you disconnect the O2 sensor and the problem remains the same, then at least you've proven that it's not related to the O2 sensor.

Another thing to pursue, when you get the time, is to go through the TFI troubleshooting info linked above. If there are parts you don't understand, please ask, and we can walk you through them.

 

[88 XLT Ranger]

Disconnecting the O2 sensor is a valid test.

If the computer can't read the value of the O2 sensor, it will go into "Open Loop" mode and calculate fuel injection information from the MAP, throttle position, and RPM, based on pre-calculated tables stored internally. This is the way it runs when first started, before the O2 sensor warms up. The engine will run slightly rich, but should otherwise work well.

If you disconnect the O2 sensor and the misfire goes away, then you've got a bad O2 sensor, or associated wiring or connectors. If you disconnect the O2 sensor and the misfire becomes continuous, then the problem is associated with "Open Loop" operation, which will narrow down the scope of the search. If you disconnect the O2 sensor and the problem remains the same, then at least you've proven that it's not related to the O2 sensor.

Another thing to pursue, when you get the time, is to go through the TFI troubleshooting info linked above. If there are parts you don't understand, please ask, and we can walk you through them.

That didn't help disconnecting the O2 sensor It did run crappy but cleared up ran smooth. I get out on the road 65mph than the popping again 35mph up the highway in low gear. It don't pop as much but bogging bad no power. I got home I can hear a tick in one cylinder missing as it idles. I did notice the overflow tank like boiling sound. The temp is always below halfway on the gauge. I was thinking could a bad Temp sensor make this issue? I seen on the help files it controls timing and lean/rich fuel. Now for testing could I disconnect that see if it helps? Once it cools off will hook the O2 back up and check the dist cap I just don't think that is the problem

 

[88 XLT Ranger]

I checked the dist cap it was bad all the towers inside where rusted one was corroded real bad. I put a new Borg Warner cap and rotor on fired it up same issue popping running like crap. You would think that would help it maybe try the temp sensor?

 

[Spott]

could a bad Temp sensor make this issue?

Nope. The temperature sender that drives the dashboard gauge doesn't control anything, only the gauge. If it were removed entirely, it wouldn't affect the engine one bit.

However, there's a completely separate temperature sensor that sends a signal the the engine computer. A better question would be: "How can I test the temperature sensor?" The answer is:

http://www.therangerstation.com/forums/showthread.php?t=151049

But before testing that, you should check the coolant level and condition.

You need to focus on the TFI troubleshooting, as has been recommended to you several times, before you look for other causes of your problem. Right now you're still grasping at straws and trying to guess the causes. If you don't proceed systematically, you'll just waste more time and parts.

 

[88 XLT Ranger]

Well, considering it is sporadic...I would say the "fixed" parts are not going to give you a solution...a distributor cap is like the distributor...it is either good or bad...something that controls the spark or the injectors or something else that is capable of sporadic performance...meaning a part that can be able to function perfectly well until something disrupts that functionality...

So far you have been seeing temporary disruptions...and maybe that's as bad as it will get...

Did you get to testing the TFI components?

Did you look into a replacement ECU by any chance? I don't think that is the problem because it is like a fixed component but can be affected by the various input...things that you've been changing that should have corrected the problem.

Thank you

Never forget please I do so much appreciate all of you trying your best to help figure this issue out. I just have gotten to the point of giving up run it like it is until it blows up. I did check the ECU that is the main computer? it all looks perfect I can't afford $150+ for a new one. I spent so much already each time I get upset no matter what I do its still giving me hell. The TFI components the only thing that I see is the wire harness going from the drivers fender well over across to the engine the flexible cover was melted below where the exhaust manifold is below. I checked each wire moved them around nothing changes. I never had any missing/popping issues until the vaccume line blew off the black round deal on the driver side fender well it has one cable going to the throttle body what it that? I put the vaccume line back on drove 1/4 mile to the off ramp stopped than as soon as I took off popping/missing

I was thinking on checking the fuel pressure again to me it just feels like it running out of fuel. Would a bad fuel injector do this off and on? I did try Red Line fuel injector cleaner no improvement

 

[88 XLT Ranger]

Nope. The temperature sender that drives the dashboard gauge doesn't control anything, only the gauge. If it were removed entirely, it wouldn't affect the engine one bit.

However, there's a completely separate temperature sensor that sends a signal the the engine computer. A better question would be: "How can I test the temperature sensor?" The answer is:

http://www.therangerstation.com/forums/showthread.php?t=151049

But before testing that, you should check the coolant level and condition.

You need to focus on the TFI troubleshooting, as has been recommended to you several times, before you look for other causes of your problem. Right now you're still grasping at straws and trying to guess the causes. If you don't proceed systematically, you'll just waste more time and parts.

I have the ECT(engine coolant temp) sensor where the thermoset housing is. It is a two wire sensor could this make this issue? I don't have an OHM meter to test it only a Multimeter would un-plugging it be a true test? I know back in 2002 when I had the Ignition module go bad we re-placed it along with a few other items before finding out it was the Ignition module

I also think I have an IAC issue it use to when starting up go to 1500 rpm's than after 4-5 min drop to 800rpm's now it starts goes to 1000 rpm's and drops to 800 rpm's in 2 seconds. Its like a boat trying to stay afloat trying to die at low idle. How do you clean the IAC? I got some chain saw gas and a high pressure air compressor to blow it out

 

[Spott]

A multimeter includes an ohmmeter, it's the settings with the "omega" (looks like a horseshoe) symbol.

TFI failure, especially temperature-related intermittent problems, is a known issue on these engines, that's why people keep recommending you work on troubleshooting it. There's a pretty good chance that it's the cause of your issues, especially since you just admitted that it's 14 years old. Do it!

The IAC will not affect your engine performance at all while driving, only while idling, so that's an unrelated problem. Clean the IAC with carb cleaner or brake cleaner, if that doesn't help then inspect the wiring.

 

[88 XLT Ranger]

A multimeter includes an ohmmeter, it's the settings with the "omega" (looks like a horseshoe) symbol.

TFI failure, especially temperature-related intermittent problems, is a known issue on these engines, that's why people keep recommending you work on troubleshooting it. There's a pretty good chance that it's the cause of your issues, especially since you just admitted that it's 14 years old. Do it!

The IAC will not affect your engine performance at all while driving, only while idling, so that's an unrelated problem. Clean the IAC with carb cleaner or brake cleaner, if that doesn't help then inspect the wiring.

The TFI module is a brand new Motorcraft unit the truck misfires and pops both when cold and hot. I looked at the testing the TFS EEC-IV worksheet it calls for 12V test light,Dvom, and straight pins. I got the Multimeter thanks for pointing out how to use it with the symbol. It has no instructions with it and has black and red pins. I can't print the worksheet out what would be the first step in testing or how have you guy's tested it "easy steps" for someone like me that has no idea of what his doing. I will go back through the wiring check it all that I can get to

 

[Spott]

"Easy steps" are fine, what are you trying to test first?

A DVOM is a "Digital Volt/Ohm Meter", the same as a multimeter.