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Discussion Starter #1
I am trying to finish up installing a donor engine and get my '86, EFI, C6 back on the road but it now runs bad when cold. I will supply the history first.

1. previous engine/setup had no cat, egr, crossover tube, smog pump or pressure reservoir. There was no significant issues with this setup and it was a reliabel and good running engine. The engine faced a death by hydro lock on memorial day. I replaced it with a good engine from an '87 f150 donor and I am having problems starting it when it is cold. It takes some flammable material shot into the air intake to get it started and then it runs rough until it warms up. I have searched here, read the Haynes manual and read fordfuelinjection.com and I have learned a ton. Also has new coil/wires/plugs, good cap/rotor. Installed injectors from a newer Mustang 5.0.
Yesterday I got the following trouble codes:
KOEO
31 PFE, EVP or EVR circuit below minimum voltage
31 PFE, EVP or EVR circuit below minimum voltage

Engine Run Codes
21 ECT out of self-test range
41 No HEGO switching detected
31 PFR, EVP or EVR circuit below minimum voltage
34 EVP voltage above closed limit

2. Today, I did a resistance check on the ECT and it ready around 48k @ cool room temp which is ok accordign to fordfuelinjection.com and the resistance lowered with applied heat. I installed the pressure reservoir and repaired 2 broken vacuum lines coming out of the main tree. No fuel smell at the feul pressure regulator vacuum connector. It is colder today, but the rough idle time and severity was noticeable reduced as I warmed up the engine. I then cleared the codes and ran the test again (changes in bold):
KOEO
31 PFE, EVP or EVR circuit below minimum voltage
11 System Pass

Engine Run Codes
21 ECT out of self-test range
41 No HEGO switching detected
31 PFR, EVP or EVR circuit below minimum voltage
34 EVP voltage above closed limit
13 RPM unable to reach lower test limit

3. Tomorrow I intend to check the fuel pressure and do a vacuum leak test as well as doublecheck the Mustang injector compatibility. Now for the questions:
Is there anything obvious I am missing?
Is there any of the emissions components that I should reinstall to fix this?
 

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Discussion Starter #2
I am still working and making progress. I have fixed broken vacuum lines and installed the vacuum reservoir. Code 13 went away after these fixes. I think most of the codes are valid with most of the emissions removed. I decided to replace the O2 sensor and found a crack in the exhaust manifold when I took it off. Luckily I have a spare exhaust manifold from my donor, but it doesnt have the hole for the O2 sensor. It looks like it will get fixed on Monday at work.

If anyone has any additional info or ideas please let me know.
 

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Well, my guess for the no start without aid would be your ECT. I'd just go ahead and replace that and see if it solves that problem.

IMO, you should put the EGR system back on. In all reality, it's only doing good for your engine.
 

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Discussion Starter #5
Thanks, guys. I have the most of the emissions components on hand from my donor f150 but I do not have a cat, and I would rather not spend the money on for the simple fact that I don't have that kind of money right now. Do I need the smog pump? I am going to go out today and piece things together to see if I can figure out how they all connect. I don't think my Haynes manual has a diagram of how they all interconnect with each other and the engine, but I do know that I don't have a return tube on the exhaust for the EGR. I think I may have a resource to have one installed. Any tech assistance on where to add the exhaust return tube or how they all connect would be appreciated.

I also found a crack in the passenger side exhaust manifold. There is no signs of exaust coming out of the crack so I dont believe it is all the way through, but I am going to swap it out after I get a hole drilled/tapped in the donor manifold for the O2 sensor (tomorrow).
 

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Your EGR system isn't reliant on the cat or the smog pump. The EGR feeds inert gases back into the combustion chamber, which lower combustion temps, and reduce NOx emissions.

If you have a newer three way style cat, as far as I've read up on it, you don't need the extra air in the exhaust line to keep it functioning correctly, so you don't need the AIR pump, provided you'll pass visual inspection without it on.

Check out Steve83's albums, I know he's got a breakdown on the EGR system for a 5.0.
 

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Discussion Starter #7
Currently, I don't require an emissions inspection. My goal is to get it road worthy and reliable. If I can add the EGR back in to overcome the performance loss and help the combustion keep cooler I will.

My immediate question is, does it matter where the EGR taps into the exhaust? I am getting a hole drilled and tapped into an exhaust manifold tomorrow for the O2 sensor and it would be easy to have a second hole added for the EGR connection.
 

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Discussion Starter #8
Update:

I replaced the cracked manifold and installed a new O2 sensor, I also replaced the Engine Coolant Temp sensor (emissions) since I was getting the related code and resistance checks were showing a slight discrepancy.

I needed to squirt some "combustion helper" into the intake to get it started (and it was 35 degrees outside). It took about 15 minutes for it to warm up, but until it did it ran like crap. It would almost die and then the RPM would jump up and it would run and then try and die again. Pushing the gas peddle would cause it to die. The old paper check at the tail pipe indicated a valve was leaking so I poured a shot B12 in the gas and the symptoms went away. Once it warmed up it was like someone flipped a switch and the idle jumped up and it was smooth. I drove it down to the gas station and put some more B12 and gas in it. It started up fine, drove fine and the trottle response was good. The best news is that it was 40 degrees this morning and it started right up, but the idle was still poor/rough.

Tonite, I am planning on putting in the proper 195 deg thermostat, rechecking all the spark plugs and thier gaps and then running codes to see what I can figure out.

Once I get this running where it is reliable I can then start reinstalling the full emissions system.
 

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Discussion Starter #12
set it back up together like it was stock.
That is a goal but I have to set priorities based on the following: I ran this setup fine for 3 years without cat, egr, pump, cross over tubes, etc., I currently do not have a garage, my income to bill ratio is unfavorable, I am possible weeks away from taking a new job which will require a move which my FSB needs to pull a small trailer, my new job will greatly improve my FSB fund and we might be selling our house soon. With that, I have to keep it running with the minimum components until I have the space and $$$ to make it better (stock)...my donor motor transmission will also be replaced with new ones at that time.

I trust everyones optinion here and the egr will make it on, soon.
 
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