The van had been setting for more than a year but was started a few times. Its a work van that has a boom to work on CATV and telco jobs.

It was running real ragged and bad idle. Used seafoam in tank and through the vac port. Found out the in tank pump was not working so replace it and tested fine. The high pressure pump works fine. Did the fuel pressure test and works just like it should. Yes have brand new gas in it and gas take was in great shape.

It now cranks up and idles like it should but every now and then it starts to idle down and might even shut off? But if you give it some gas then it responds right back and if it does cut off it will start right back.

If you put it in gear it seems to be fine but when you go to drive it and then step on the gas its response is sluggish and if you try to give it more gas it will start back firing but will keep going but very little power even if you floor it?

What am I over looking?

I have two manuals and wiring diagrams but as for as helpful info on trouble shooting they are not that helpful.

I have also plugged in my code reader but it say the veh is not responding? I am going to try and find out why today that it want read? Its been years testing one of these but never had a problem before. Maybe a wire is cut somewhere? As much stuff that is on this van to make it a work one I would doubt it one bit that a wire got damaged or re routed?

I really need to get this thing running so I can sell it. My son gave it to me to help bail him out of a large storage bill and I would like to get my money back ASAP if I can get it to run correct again!

 

Well I feel dumb at this point because it had been so may years testing an OBD I I was forgetting to hook up the other single wire to my reader!!!!!!!!!

My KOEO passed and all it did come up with was code 31 the EGR valve
The EOER came up with the #12 A guy was having this same problem and codes and he "turns out the replacement EGR was stuck open [less then 10K on it], now shows no codes and runs great... so much for parts from N**a"
And this fixed his problem. So looks like I might have the same problem. My ERG valve when running the test in the book didn't pass what it said. I was using the Haynes test for it.

 

Ford Fuel Injection » Idle Air Bypass (IAB) Click on this link and maybe clean this valve (use carb cleaner or similar but don`t get it in the electrics).
Hopefully other opinions will follow.

 

I did that test not even knowing about it or had not got to reading it. as I was unplugging it the motor just shut down. So I guess it is working ok. I will check and clean it any way. At least it is one part I can get to easy without have to go to church for the next week because of all the bad words you have to say to work on dag vans And I have a few of them around that are on some 90's 4.0 Explorer's at least they look the same?

Thanks for the info. Now if I could fig out how to close off the EGR valve so I don't have to try and get it off that would really help also?

I had read the article on "Integrated electronic/mechanical EGR valves" and the fix below it and might work?
EGR Systems: Operation and Diagnosis

 

Well what a heck of a day. Trying to get parts ready for powder coating and trying to get this van running correct. I am tired.

Well all the test I ran with the code reader say the same. 31 and 12. I check the Idle Air Bypass (IAB) valve and it was clean but did a cleaning on it anyway.

I pulled of the sensor off the EGR valve and then I sprayed the inside wit carb cleaner and then held my hand over it and pulled a hard vacuum on it a few times and would hear it pop back shut when I removed my hand.

I can not get the sensor to read correct when installed before the vacuum or when I pull the recommended vacuum on it? So my guess is that it is bad? But what has me confused and maybe I have just read over it? I have never felt a vacuum on the line that goes to it? Is that because the sensor is not working and not sending the info to the unit near the back of the motor that controls it?

This is one time when I wish I had the factory manuals like I do with my 78 f250 and my 2000 f550. They really come in handy.

I sure do need to get this thing out of my HAIR as long as I still have any.

 

Very far from an expert but it sounds like the EGR valve itself is good but the EGR position sensor is bad. It is the computer that signals the EGR valve to open but only at certain times in the drive cycle and never at idle so you won`t detect vacuum.
However if the EGR valve is good and not opening at all, then you should have no running problems. If the EGR valve is bad (maybe weak spring or carbon buildup preventing it from closing properly) you will have running problems.
As you have no vacuum going to it at all it is unlikely to be a vacuum problem causing the bad running.
http://www.fordfuelinjection.com/?p=43 Read here also

 

Well my sensor is diff from that one but looks like they all do the same thing.

When I had it off and motor running and my hand over the hole and started pulling a vacuum the idle started fluttering as it would open up and then as soon as I would let go the idle would come back to norm. So looks like the sensor is what is bad and I can't get the proper readings from it also.

Now if I understand correct and with the valve staying closed and I also had the vacuum line plugged off that when I drove it around the drive and tried to give it gas and it would do the intake back fire then the EGR valve wouldn't have caused this so it is not the problem I am having!

Not sure if the code 12 (could not control rpm during koer self test) even has any thing to do with it? I did all the test and all looked good as for as I could see unless it has to do with the PCM? This code can also come up with code 31 I have read?

When I was test driving it around the yard one of my bike customers said it was running rich or either with me trying to make it go and it back firing put extra gas into it that didn't burn and made it smell that way?

If I can ever find the cause of the back firing through the intake then I might win this battle or either SHOOT the VAN

Thanks for your help and maybe between the two of us we will find the problem?

 

Definitely sounds like the EGR sensor is bad so replace that, and check the timing. To do this remember to remove the spout plug on the distributor harness to disable computer advance and set the base timing at about 10-12 deg(10 is factory spec). Other possible causes of the backfiring you describe is misrouted plug wires or cross firing between wires or a metal engine component, the best way to see if this is happening is to run the motor somewhere that is completely dark, look for the light show and replace or re-route the wires to make it stop. On this motor cylinders 6 & 5 follow each other in the firing order so these wires must be seperated, and just for the record the correct firing order is 13726548, the distributor turns counter clockwise, cyl #1 is passenger side front, and cylinders are numbered 1-4 front to back on the passenger side and 5-8 front to back on the drivers side.

If all this is correct and you still have the backfiring problem I'd suggets checking compression and doing a leakdown test for a potential burnt or broken valve.

 

Well guys I have so busy that I put this Van thing on the back burner. Well the first of the wk before the dag heat set in I decided to run a test on it with some starting fluid looking for a vacuum leak that a good mach friend told me to look for. Well all did fine. I got inside and put it in gear and started giving it gas while in gear and no problems. So I drove it around the yard and gave it all the gas I could give it and it never did any thing but go and go so all I can guess at this time is that all the Sea Foam I had run through the system maybe cleaned out what it needed while it was just setting there?

All I can say is thinks for trying to help and now this van is getting ready to be sold