Well I have been workin on my 302 efi for some time now, I put a new front tank, New rear pump/sending unit, changed the canister filter, put a new front pump and filter on it plus a new fuel pressure regulator since there was fuel in the vacuum line and put a ignition module. I drove around for a few days just fine and now it will idle decent put when you start to rev it, it will start to spit and sputter and pop and then let off the throttle it will idle decent again. You can do this a few times and then it will die, can turn the key off and turn it back on wait 5 to 10 sec and than it will start back up and do the same thing again. Iam pretty clueless as what to check next, its a pretty decent truck to drive around when it runs right. Thanks in advance

 

Check your electrical connections to the fuel injectors. Sometimes the wires can back out of the connections, and a loose wire will cause the symptoms you've described. You may have disturbed one when working on the regulator or ignition module.

 

It also sounds like you may have picked up a little water in your fuel,Check your electrical connections as was suggested and check you coil connection as well then try some dry gas in your fuel.Did you check for codes,if not I would start there.

 

Always pull codes on a EFI engine before spending a lot of money guessing on the problem. This site tells you how to do it with a testlight or analog voltmeter. Ford Fuel Injection

 

Ya I dumped in a bunch of heet in the tanks and also filled the tanks with fresh gas. I also hooked a code reader before too and nothing came up, this trucks been doing this for along time just getting around to fixin it. Ill try it again and see if something new popped up. Dont these efi engines have a check engine light or is it to old for that?

 

It has an emissions light...its the far left light on the top of the dash next to the left directional light. It doesn't indicate engine problems. It comes on after a pre-determined amount of time to prompt you to service your emissions system. Its controlled by a small black box located near the wiper switch. I've seen it called an inferred mileage sensor or an extended life sensor.

 

You should get a "11" which means everything is ok.

 

Ya just read that, lol. Iam gonna try it again tomorrow and see if I can get anything to pop up.

 

If its not getting any more fuel when you rev it up and maybe getting more air it sounds like its not seeing a signal from your throttle position sensor on the throttle body. I have seen them get bad spots in them. You can check them with a volt meter. It should be below 1 volt closed and increase to a max of 4 or 5 to wide open. I think you can check it koeo.

 

As I recall there is no bulb or provision for one under the "emissions" lens in the dash, there's a hole but no connector so any info has to be pulled from the test connectors under the hood. In my experience with my '86 the distributor itself causes a problem similar to what you describe. It acts like it's running out of gas after it's run for a while, sometimes it was a few minutes other times it took as much as 30 minutes before it would crap out. It was the TFT under the rotor in the distributor causing the problem for me. If I let it cool for about 15 mins it would run fine for about 10-15 mins then do it again. I've replaced my dist twice for the same problem in the 270,000 miles I driven this thing so far. About 70 bucks at AutoZone.
Another problem with mine is after 6 months or so the big connector on the computer loses good connection with the computer. It won't rev above about 3300 RPM and pings like a SOB. All it takes is to pull the connector lose and re-seat it and I'm good for another 6 months or so. In the '86 the computer is mounted vertical under the dash above your right shin facing straight down, the connector has a 10mm bolt holding it to the computer so all you have to do is unscrew the bolt then screw it back in again. I tried pinching down the connectors in the plug and coating everything with silicone grease but it didn't help much as far as keeping the connections good. I just re-seated mine again last weekend so I could get it up to 80 for my trip back from Yuma. (12 MPG)

JohnF
Phoenix

 

I did pull the koeo codes and act sensor out of range and the evap control system below minimum voltage, Is there a way I can bypass the egr sensor? also do I need to fix these codes before I do koer test? Thanks

 

Air charge sensor out of range is normal if it's cold outside(below 50f I believe).

You cannot bypass the egr sensor without throwing a code. See how that works? Anything not hooked up or not quite right, the computer knows it and spits out a code. I would go ahead and do the engine running test too.

 

I saw this on eBay Motors: '86-95 FORD TRUCK F150 F-250 BRONCO EGR ELIMINATOR (item 300290499558 end time Feb-06-09 19:25:27 PST), Thats why the act turned on, it was 20 degrees out, lol. I did find a egr sensor on ebay too for a good price.

 

Years ago I kept getting the EGR code in my '86. After a lot of reading, at the time, I found there were 2 different sensors for my year. I made sure I got the right one but still got a code. After more reading I found a site where the actual readings of the sensor were given and discovered even the right sensor was giving the wrong readings. Luckly the pin that moves the sensor in the one I had was too long so I kept trimming it off until I got the correct readings. I haven't had the EGR code in at least 15 years now.

JohnF

 

Ya the fordfuelinjection site says there is a white and black one and gives the voltage reading too. I would like to just get rid of it all and be done with it.