86LX 5.0 pops,sputters,backfires

[jrichker]

Some help for exhaust restriction diagnosis copied from the Chiliton Manual for Mustangs

 

[mark5]

When I unplugged the map sensor (which defaults its abilities) it still ran terrible and idled beyond terrible. Injectors is my next "to buy" item. Plan on getting the Generation3 injectors with the old style plug. They are suppose to be alot better than stock. They have 4 holes that spray fuel as apposed to 1. Doubt it is an injector mainly because it runs really strong when it's cold. If an injector was bad, think it would act accordingly all the time, not just when the car is warmed up. BTW Mark, Holy crap! With the setup on your car that could be a number of problems but i bet on 5cylinders it's faster than mine on a good day, sheesh!

Thx my man...I wouldn't bet on that though. When it gets lined out I'm looking for mid to low 10's.

 

[EliteLX]

Being the Neanderthal that I am, I sawzalled the cats out bout an hr ago only to find out they were already previously gutted. Needless to say that didn't do anything except give all the animals in the woods a heart-attack when I got on it.

 

[EliteLX]

I tried following it on the wire diagram above but can't figure it out. Can someone tell me what the small plastic sensor/relay box looking thing that is mounted to my drivers side fender wall with a plug stuck in the bottom of it is? Looks like 4 wires on the plug connector.

 

[jrichker]

I tried following it on the wire diagram above but can't figure it out. Can someone tell me what the small plastic sensor/relay box looking thing that is mounted to my drivers side fender wall with a plug stuck in the bottom of it is? Looks like 4 wires on the plug connector.

Please post the wire colors with the solid color and stripe color. They help identify the circuit and its function. Do not depend on a photograph to do the job, since the camera and then the device the photo is viewed on can alter the color presentation. Clean the wires with some solvent before trying to identify them.

 

[striker911]

Same here.

My car has been on the back burner since I work all over the country and have been gone 5-2 weeks at a time. Plus I bought a house with no garage 3 months ago .Hope to get a garage built soon. But here is my input. I think my problem is injector related. It does the same stuff. Can run great till it gets warmed up and then it gets to missing and backfiring with very little power.

Is it worth getting a injector quick probe? Has anyone used one like this?
http://cgi.ebay.com/ebaymotors/ws/e...0609399907&viewitem=&sspagename=STRK:MEWAX:IT

I want to test the voltage but from what I read everyone says to test leads at the plug and as we all know thats not easy to do in this car. This is why im looking at the quick probe.

EDIT: Just went to check the link and it wont work so just paste this in the search box at ebay.

Waekon Universal Electronic Fuel Injector Quick Probe

 

[EliteLX]

I ordered the gen3 injectors today as well as a throttle position sensor. It's raining here today so I will take a look at those wires to that relay tomorrow and post it on here.

 

[EliteLX]

Been a real busy past few days. Got the gen 3 injectors in last night. About to go let her warm up and take her for a spin. Still need to check out those wires on the fender wall. While pulling old injectors I did find a problem with 1 of them. The lower O ring gasket was destroyed. Dunno if that was the cause of my problems but, will find out today....

 

[EliteLX]

After all the time and money spent maybe I should have removed and checked injector O rings earlier. Apparently that WAS the problem and my baby is running like a dream! CHECK FUEL INJECTOR O RINGS!!!!!!!!!!!!!!! Thank you so much for everyone's input on the situation. I appreciate it beyond compare. It was a bad o ring allowing air to be pulled into the cylinder once the engine was warmed up and the metal around the o ring expanded enough to let air by. I am possibly the happiest gearhead on the planet right now.

 

[jrichker]

After all the time and money spent maybe I should have removed and checked injector O rings earlier. Apparently that WAS the problem and my baby is running like a dream! CHECK FUEL INJECTOR O RINGS!!!!!!!!!!!!!!! Thank you so much for everyone's input on the situation. I appreciate it beyond compare. It was a bad o ring allowing air to be pulled into the cylinder once the engine was warmed up and the metal around the o ring expanded enough to let air by. I am possibly the happiest gearhead on the planet right now.

I am glad that you got your problems fixed, and I appreciate the fact that you updated us with your findings. I will certainly add that to my troubleshooting checklists and maybe be able to help someone else in the future.

 

[mark5]

After all the time and money spent maybe I should have removed and checked injector O rings earlier. Apparently that WAS the problem and my baby is running like a dream! CHECK FUEL INJECTOR O RINGS!!!!!!!!!!!!!!! Thank you so much for everyone's input on the situation. I appreciate it beyond compare. It was a bad o ring allowing air to be pulled into the cylinder once the engine was warmed up and the metal around the o ring expanded enough to let air by. I am possibly the happiest gearhead on the planet right now.

RIGHT ON MY MAN!!! That's good to hear. I'm gonna add that to the things I need to check while I figure out my problem. Congrats again on finding your problem my man. I'll still gonna post what solves my problem when I get it fixed!!!

 

[EliteLX]

Car is still running great. Just wanted to stop by and say thanks again to all who helped me troubleshoot. Cheers

 

[rainey27]

91 mustang problem

i have a 91 mustang with a 342. i am wanting to know if anybody can tell me what might be wrong. the problem i am having is at about 2000 rpm my car starts to sputter and then makes 2 loud pops from what sounds like its coming from the bottom of the motor and then just takes the heck off like it is suppose to. any suggestion would be appreciated. i want to maybe narrow down what it could be. and what should my timing be set at i have at 10* btdc.

 

[jrichker]

i have a 91 mustang with a 342. i am wanting to know if anybody can tell me what might be wrong. the problem i am having is at about 2000 rpm my car starts to sputter and then makes 2 loud pops from what sounds like its coming from the bottom of the motor and then just takes the heck off like it is suppose to. any suggestion would be appreciated. i want to maybe narrow down what it could be. and what should my timing be set at i have at 10* btdc.

Please start your own post and I will try to help you. Piggybacking on someone else's post is bad manners, like showing up for dinner uninvited. It is not very effective since the problem has already been resolved for the owner, and people will overlook your questions.

 

[rainey27]

Please start your own post and I will try to help you. Piggybacking on someone else's post is bad manners, like showing up for dinner uninvited. It is not very effective since the problem has already been resolved for the owner, and people will overlook your questions.

sorry man new to the site an really dont know how it works. thanks for letting me know though.

 

[Reddragon]

Now that sounds like something that could have been the problem which is why i installed a brand new distributor 3 days ago. Still having the same issue. When i run cylinder test it constantly gives different codes. I.E. first time i got code 8, i moved sparkplug in cyl 8 to cyl 7 then reran test. It gave me a 7,2,and 1 as being problematic. I have run the cylinder test many times and each time it gives different cylinders as problematic. Have brand new plugs and wires, new distributor, proper fuel pressure to the rail,brand new MSD TPI, new cap and rotor, new ford racing pushrods,have switched out EEC for a spare and still no change after the car warms up. There is a huge difference when it is cold as it idles much better and runs very strong which is expected in a car that has had $1200 worth of brand new parts. As it warms up, it gets progressively worse from spitting and sputtering at 5k to 4k then finally all the way down to 3k which is the cutoff. This happens even if I'm on partial throttle anything over 3k rpm after the car has come to full operating temps and its spit, sputter and backfire city. I apologize for the egr rant. I'm just really fed up with this issue and spring is here. I want to be at the track and this problem is killing my season so far. I have this posted on many Mustang forums and noone has a clue. I'm getting close to going carbureted and being done with it.

on my 92 it was the pip now I added an 85 to the stable and it’s doing similar thing but it’s not that , I read an article earlier that I’m hoping it’s not cause I just built this motor and it’s saying a blown head gasket could cause full throttle misfire but fine during normal driving .