running rough then dies

[ayr423956]

On my way home Wednesday my 86 2.9 Bronco ii started jerking and had a loss of power. It would barely go and could barely get to third gear. I put a fuel pressure tester on it and had about 10 to 15 psi tops. I replaced the fuel pump on the frame and the fuel filter between the pump and the engine. I The replaced the canister fuel filter in December. I checked the fuel pressure and got about 37 to 42 psi and ran good.

I did not have a problem Thursday.

On Friday I drove a half a hour with no problem. I parked it for about 6 hours and on the way home it ran fine for about 10 min started jerking and a loss of power again. I searched the forums and I decided to check the fuel pressure regulator and I could smell gas in the vacuum line. So I replaced the regulator and it seemed to run the it as since I got it.

Today it stared fine and it did good on the test drive. This afternoon I was going the junk yard and got about 3 miles and started jerking and had a loss of power.

Its some what a intermitting problem that's gotten worse any help or advice is appreciated. Thanks

 

[adsm08]

Unplug the oxygen sensor and drive it for a while, see if it still does it.

 

[Lil-Pony]

Doesnt the 86 have a tfi?

 

[ayr423956]

I replaced the tfi and the pickup in the distributor have been a couple months ago.

 

[ayr423956]

I unplug the oxygen sensor took it for a drive and it did not change anything.

 

[ayr423956]

update

I swapped the tfi the one on my dad's truck and both trucks ran fine. Today my truck started jerking with a loss of power again. It also has a backfire from the engine compartment when under a load. It was not a bad as before but I still got a problem. Any other tips will be appreciated thanks.

 

[Lil-Pony]

Cats?

 

[GentleRF]

Check the ignition timing by first pulling the shorting plug from the wiring harness on the right (passenger) side of the engine. It should be ten degrees. If it isn't, the loosen the clamp bolt where the distributor enters the engine, set it to ten degrees, then tighten the bolt back up. I had this happen on the '89 Ranger I gave my youngest son long before I gave it to him.

Rick in East Bremerton

 

[ayr423956]

update

Today it drove to and from school fine. I set the ignition timing at 10 deg. I also checked the tps and it tested good. I cleaned the air tep sensor.

I parked it for about a hour after I got home. when I went to start it, it idled rough I revved it for about 30 sec and then ran fine. I got about 3 miles and it lost power and die. It sat for about 2 min started and ran for about 15 miles with no problem. and my teacher does not think the cats are the problem.

any more tips thanks.

 

[RustedRanger]

Mine had a bad wire on the plug in to the coil,it looked fine. Cleaned wires one day and by moving the coil plug in (little wires) it caused it to not start. While on the diagnostic computer you could see the coil output change and the idle get rough when the wires was moved around. Also you could try checking fuel pressure under load while driving.

 

[70roadrunner]

I had similar symptoms on my 84, turned out to be the screws backed out of the rotor. put them back in and ran great

 

[ayr423956]

update

I swapped map sensors last night and seemed to run a little better. On the home today I stopped to get gas. when I started it back up it idled rough I gave it some gas and it went away. I made it 0.3 miles and it lost power and died. I pulled over and waited 1 min and it start and drove home fine.

Is afternoon at home I let run and wiggled wires and tap on sensors. It did not change any thing. I checked the distributor cap and rotor and they are fine.

the fuel pressure is about 30 to 35 when idling. It does up when I give it gas.

any tips thanks.

 

[RustedRanger]

The best tip I can give from what I've experienced is to find a good shop who does auto electric/diagnostics. They use a diagnostic computer not a code reader and since the problem pops up pretty quickly they should be able to find it. These days buying one wrong part that doesn't fix the problem can cost as much as finding out what it is first. I sure miss the days of tuning a car with a wrench and a screwdriver