EFI problems.....?

So, 5.0L from a 1990' TownCar, with AOD into my 86' B2.
Mounted, fluids buttoned up. Wiring spliced to Bronco, Plug in the EEC and hit the key. VROOOM.

Very exciting.

BUT it starts alright and runs, good enough to drive it 10 min into town for exhaust. It did not want to run well enough to drive home from exhaust. I re-set the EEC, then was able to drive home. I was NOT happy with how it was running.

Started investigating. Pull 1 spark plug wire off the distributor and see what changed. When I pulled 7 of the 8 wires it made a dramatic/noticeable difference. The #4 cylinder nothing changed, it was still getting spark, but having that plug wire disconnected did not change how it was running (which was poor to begin with) (BTW all spark plugs where gross with soot, I think it was over fueling due to #4 not firing and just cycling oxygen onto the O2 sensor)

So, we have spark to #4, obviously time to investigate fuel. Pulled injectors, sure enough #4 was gummed right up. Pulled and cleaned all injectors. Re-O-ringed and re-installed injectors (vegetable oil on the O-rings). Reassembled intake and all that junk. Turned the key. VROOOM

Very exciting.

It ran way smoother and sounded much nicer. For about 5 minutes.
Then it began to get worse and worse, back to the point of running like a bucket of garbage, like it was before all the injector work.

SOOOOO obviously the computer is getting problematic information from somewhere! Everytime I re-set the computer it runs awesome, for about 5 minutes, then continues to get worse. These comps fun of averages (right?) so it is getting a signal to do something different, which is making things worse.

ANYBODY GOT ANY IDEAS WHAT MIGHT BE GIVING ME THIS BAD INPUT?

PS: all the emissions trinkets on the passenger side of the engine are gone. A: no space for them B: why would I want that junk?
Could it be that this emissions junk sent the comp some sort of signal that is now absent that is now screwing me?

I want my EFI

I think it is the superior option because I am an serious offroad rig. And because (well this is whats supposed to happen) once I get it running there is no more fussing with it!

You need to pull the codes from the EEC, otherwise you'll be shooting in the dark.

Code readers are expensive.....

Hello

A code reader for that ecm is $50 cdn at Canadian tire in Canada. These ecm are the older type before orb came in. Do you have a hand held volt meter? If you do try this http://therangerstation.com/tech_library/OBD_I.html . This test is good on computer controled ford cars with eec-iv from 83 to 92-95 (depending on model). Let us know what happens. Is this motor a H.O. or S.O.? Did you switch parts switch any parts from different 5.0?

igiveup

I'm at work till 5 moutain time, my dad just called me from home, he was bored and messing with it.

He pulled the ThrottlePositonSensor off and checked it, all appeared to be in order. Ran it again = poor.

He pulled the TPS off and opperated it with a skrewdriver and BAM dramtic results. First it stalled when he turned it fast, then when he turned it slow it improved to the point of running correctly.

So, spark system appears to be good. Fuel system appears to be good, TPS is suspect!!! Anybody have any experience with them?

igiveup said:

Hello

A code reader for that ecm is $50 cdn at Canadian tire in Canada. These ecm are the older type before orb came in. Do you have a hand held volt meter? If you do try this http://therangerstation.com/tech_library/OBD_I.html . This test is good on computer controled ford cars with eec-iv from 83 to 92-95 (depending on model). Let us know what happens. Is this motor a H.O. or S.O.? Did you switch parts switch any parts from different 5.0?

igiveup

Click to expand...

Thanks for the input man! Good to know a code reader for this thing is cheap. But I dont have very much faith in that "code" system. Once I get a code what do I do with it? Is there a code legend on the back of the box? How indepth is it?
For $50 i might just pick one up thought. Probably cant' hurt.

(S.O. engine, stock, original parts. It got a poor-man rebuild (hone and new cylinders))

Get a voltmeter and probe the two wires going to the TPS. Turn the ignition switch to on, but don't start the car. Adjust the TPS position until it reads .9-.99 volts. At WOT it should not read more that 5 volts. Also operate the throttle body thru it full range of motion to make sure you get a smooth increase from .9 to 5 volts. Any spikes or dropping to 0 and the TPS is bad. Good luck!

Hello

Try http://forums.corral.net/forums/index.php . These guys can help you on the computers and changing the motor to a H.O. if you want. It is a mustang site but the computers are simmilar. The codes will be the same between H.O. an S.O. motors. They have helped me in the past with my computer codes and problems.

igiveup

Thanks for the input guys!! I will defiantly be testing that TPS sensor. Luckily I have a spare intake manifold from the junkyard so I have two to work with!

ARGHHHHHHHHHH

The TPS sensor that was ON the engine did not pass test. Idle it measured 0.34 volts, WideOpen it measured 3.14 volts = fail

The 'spare' I had measured 0.6 at idle and 4.7 at WOT. = Mostly pass?

Pulled and cleaned O2 sensors.

Put everybody back on, (the 'better' TPS sensor) and it ran significantly better. Not 100%, but much better. For about 3 minutes

At about 4 or 5 minutes it has deteriorated to the point of it kills itself due to some sort of random large hickup.

WTF, EFI is losing favor....

Where else to look? Where/who is sending the EEC bad information??

(I dont have a code reader for now, and again I ask, once this thing tells me a 'code' what do I do? How do I know where to look?)

Hello

Get the codes and let me know the numbers. I have a book here that goes in depth on the codes and let you know what they are. The codes aren't perfect but points to the area that could be the problem.

Now it could be a simple as a bad ground.

How did the car run before the motor went in the B2?

igiveup

Check your fuel pressure also we had problems similar to that and fuel filter and fuel tank was gummed up. Fuel pressure would gradually fall off you need between 35 and 45 pounds of pressure.

THANK YOU GUYS FOR YOUR INTEREST AND CARE

I appreciate it!!


What do you fella's know about O2 sensors?? If there is some paint on the outside of mine might that effect how they operate?? I have been reading on them and I'm begining to believe that they are some sort of chemical difference (producing a voltage) one side of the equation measures the oxygen OUTSIDE the exhaust then the bung in the manifold measures remaining exhaust INSIDE the manifold. The comparative value helps the engine dial in how much fuel to input to achieve the desired stoichiometry.

Thoughts?? (Mine have SOME engine enamel on the outside from when I painted it on the stand, I am going out to clean them after I hit "submit")

igiveup said:

Hello

Get the codes and let me know the numbers. I have a book here that goes in depth on the codes and let you know what they are. The codes aren't perfect but points to the area that could be the problem.

Now it could be a simple as a bad ground.

How did the car run before the motor went in the B2?

igiveup

Click to expand...

Thanks for your help! I may get a code reader tommorow if I'm still haveing grief. What am I looking for when I head to Canadian Tire? Any specific brand?
How did it run before? It didn't. I got it from the Pick-N-Pull in edm, the whole car. It was gross, the engine was full of shit, the trans was COOKED. Epic fail, but it's been rebuilt, and re clutched, and this leaves me in the dark looking for problem areas.

Bruce said:

Check your fuel pressure also we had problems similar to that and fuel filter and fuel tank was gummed up. Fuel pressure would gradually fall off you need between 35 and 45 pounds of pressure.

Click to expand...

Hmmmm, good input. My 2.9 that I pulled didn't seem to have any fuel problems...
How would I check fuel pressure? There is a "valve stem" very similar to what is on tires on the top left of the fuel rail, check there?

Yes that little valve is the fuel pressure tap port, not sure what is available out there for a gauge set to check it i just happen to a fuel pressure gauge set.

Paint on the out side of02 sensors shouldnt effect it,if you have a volt meter put the positive to the black wire(you will need something to pierce the black wire to hook meter lead too) on the 02 and the negative volt meter lead to ground on battery, when engine is warmed up sensor should read between .1 volts to .9volts. Also you may need to check 1 of the white wires to be sure you have 12 volts to it whenkey on since 02 sensors are self preheated.

I cleaned them shiney-new and reinstalled.
Still same thing.

http://video.cardomain.com/Clip.aspx?key=084C518583A30154


I tested them on the workbench with the propane torch and they checked out. One was a-bit slower to respond, but they both operated. Once they where HOT they read 0.9 volts, and by backing off with the heat you could make it read anywhere between there and 0.1

Back to square 1
At least I have a few knowns....