EFI Randomly Stalls

[stock74]

I replaced the TFI Module and PIP with brand new Motorcraft parts a month or two ago because I was having some issues. Mainly the engine would randomly stall and could be restarted almost right away. Also, the engine sometimes would not start even when the engine was cold. Then it would randomly start working again. I was also experiencing what seemed like a random misfire as well. The codes I received were (95,14,33,94,44).

Now a month or two after installing the new TFI Module and PIP when I was driving home the other day the engine twice acted like it was going to die and then when I came to a stop the engine stalled. I immediately put it in neutral and the turned the key. The engine started right up and ran fine the rest of the way home.

As soon as I got home, I pulled codes and ended up with the same codes I had prior to replacing the parts. After replacing the parts I had pulled codes and code 14 was gone or so I thought. It bothers me that with fairly new parts code 14 is back unless it never actually went away. I also cannot figure out why I am getting a code 95. I checked the electrical connections at the fuel pump and everything seemed fine.

Codes (33,94,44) are from not having EGR and Thermactor Air Injection System. I do have resistors (purchased as a kit from RJM) installed for the EGR and Thermactor Air Injection System.

Any help is greatly appreciated. I would really like to get the Bronco running reliably and not have to constantly worry about when it is going to stall or not start. Especially when having to drive in traffic. Also, I would like to take it on a camping trip this summer but do not trust it at the moment to make it that far. I am almost to the point of getting rid of this EFI setup and getting onboard with the explorer OBDII mass buy.

Thanks in Advance!

 

[EFI Guy]

95 could likely be caused by a bad fuel pump relay. They are cheap enough, I'd just toss a new one at it. Wouldn't hurt to give it a new EEC relay at the same time. I don't normally recommend using new parts to diagnose, but in this case I would.

 

[Viperwolf1]

The resistors only prevent code 31. They have no affect on 33, 44, or 94. You will always have those codes unless you have the ECM tuned.

Might want to list out everything you have for harness, ECM, MAF, injectors, etc.

Code 95 doesn't care about connections at the pump. It samples the voltage directly from the fuel pump relay. That's where you need to look. Here is some troubleshooting info: http://sbftech.com/index.php?PHPSESSID=86be8ed9c7ebb89450bb3a0fe807072f&topic=29871.0

It sounds like you used a factory harness. Might want to trace out the PIP wire between the TFI and ECM.

 

[stock74]

95 could likely be caused by a bad fuel pump relay. They are cheap enough, I'd just toss a new one at it. Wouldn't hurt to give it a new EEC relay at the same time. I don't normally recommend using new parts to diagnose, but in this case I would.

Thanks for the suggestion. Would be easy enough to try before digging into the wiring harness. Unfortunately I have not been able to find too much help on troubleshooting for different codes. About the only thing I could find up until now for code 95 for instance is check for bad grounds and loose connections.

The resistors only prevent code 31. They have no affect on 33, 44, or 94. You will always have those codes unless you have the ECM tuned.

Might want to list out everything you have for harness, ECM, MAF, injectors, etc.

Code 95 doesn't care about connections at the pump. It samples the voltage directly from the fuel pump relay. That's where you need to look. Here is some troubleshooting info: http://sbftech.com/index.php?PHPSESS...&topic=29871.0

It sounds like you used a factory harness. Might want to trace out the PIP wire between the TFI and ECM.

Thanks Viperwolf for clearing up my misunderstanding of the codes. I am running an A9P computer, modified '89 mustang harness (removed the EGR, EVR, CANP, TAB & TAD solenoids and added resistors). I forgot the resistor values but they were purchased from RJM and specifically labelled as to how and where they get connected. So, I assume the resistors are fine. The sensors have all been replaced at some point since I did the conversion about 9 years ago. All of the sensors are motor craft and were new when replaced. The injectors are 19 lbs, MAF and throttle body are stock mustang components.

The fuel pressure is around 40 psi at idle with the vacuum connected to the regulator. I do have a fuel pressure gauge with an electric sending unit and have not noticed anything strange going on with the fuel pressure. The times when the engine would not start; I verified the pump would turn on and that there was roughly 40 psi fuel pressure.

I have a high pressure pump mounted near the gas tank ~12 inch hose length from the tank to the pump.

I did remotely mount the TFI module similar to how to how it was done in this procedure: http://www.therangerstation.com/tech_library/remote_tfi.htm

The remote mounted TFI conversion was done about 1.5-2 years ago. I had a TFI module die while coming home from a camping trip so I thought it would be a good idea to get the TFI module away from the engine heat.

You mentioned that I should trace the PIP to ECM wire. Do you mean just verify it with an ohm meter or take apart the harness and physically trace it?

Please let me know if you have any questions about my setup.

Thanks Again for the help.

 

[Viperwolf1]

In that case trace the PIP wire from distributor to TFI and ECM. Ohming it would be a good start but you'll likely find a loose connection in one of those locations.

 

[stock74]

In that case trace the PIP wire from distributor to TFI and ECM. Ohming it would be a good start but you'll likely find a loose connection in one of those locations.

Thanks! I will give that a try and report back with my findings.

 

[Viperwolf1]

Here is some good info about the remote TFI. http://classicbroncos.com/forums/showthread.php?t=197853

 

[stock74]

Here is some good info about the remote TFI. http://classicbroncos.com/forums/showthread.php?t=197853

Hmmm... I wonder if that would be a better solution vs. my suede remote tfi that I have now. I checked the wiring with an ohm meter. The PIP to ECM checked out fine. Initially one of the connections in my remote TFI harness did not get a reading. After stepping away from the Bronco for a minute to think about it. I tried again and the connection worked. I am wondering if that remote TFI harness is flakey.

Any ideas on what I should do? I would simply move the TFI back to the distributor but I am afraid the burn it out in no time.

Thanks for your help!

 

[Viperwolf1]

I would bypass the remote wiring and see. I've never had a problem with the distributor mounted TFI.

 

[stock74]

After thinking about it that does seem like the next best thing to try along with the relays for the code 95. Especially since I would rather not throw parts and money at a problem without having some level of confidence it will fix the issue.

I will keep this thread updated as to whether or not this seems to fix the issue.

 

[stock74]

Well I removed the remote TFI setup this evening so now the TFI module is back to being mounted on the distributor. I hope this was the right decision. I took the Bronco out for a drive. The engine seems run the same as before. I just hope it runs more reliably now.

I still need to purchase a couple relays to see if I can clear up code 95. I ran a KOEO when I got back this evening. The only code that showed up was code 95. I did have the computer disconnected for probably a good 20 minutes or so last night when tracing the PIP wire so that I would guess is the likely culprit for why codes 10, 14 and 33 have cleared up. Hopefully, code 14 does not rear its ugly head again.

Thanks again for the help. I am still open to ideas on what might be causing the issues I was experiencing.

 

[stock74]

Thought I would provide an update. This evening the idle seemed a little rough and possibly a little high so I decided to try the idle reset procedure on sbftech.com. So far I am pleased with the results. The idle is lower and the engine seems to idle smoother so far. I took it out for a good 30+minute drive since it is a nice evening outside.

For anyone that wants to try smoothing out their idle I would suggest trying this procedure.

http://sbftech.com/index.php/topic,1031.0.html

 

[Sporto]

Thought I would provide an update. This evening the idle seemed a little rough and possibly a little high so I decided to try the idle reset procedure on sbftech.com. So far I am pleased with the results. The idle is lower and the engine seems to idle smoother so far. I took it out for a good 30+minute drive since it is a nice evening outside.

For anyone that wants to try smoothing out their idle I would suggest trying this procedure.

http://sbftech.com/index.php/topic,1031.0.html

Thanks for the follow up stock74. I was reading your thread with interest, as I am experiencing a similar set of issues with my EFI conversion (and Viperwolf is helping me too )...Anyway, just so I am clear on what you did, you relocated your TFI module back to your distributor and it cleared up the stalling issue? The relays did not improve anything or eliminate the codes being thrown? Just trying to wrap my brain around what you did. I have a SD setup not MAF, and my codes are 16 and 12, so my problems are more idle or vacuum related that I can tell. However I will get it figured out, and I was happy to read that you did the same. Good luck with it.


Rich

 

[stock74]

Thanks for the follow up stock74. I was reading your thread with interest, as I am experiencing a similar set of issues with my EFI conversion (and Viperwolf is helping me too )...Anyway, just so I am clear on what you did, you relocated your TFI module back to your distributor and it cleared up the stalling issue? The relays did not improve anything or eliminate the codes being thrown? Just trying to wrap my brain around what you did. I have a SD setup not MAF, and my codes are 16 and 12, so my problems are more idle or vacuum related that I can tell. However I will get it figured out, and I was happy to read that you did the same. Good luck with it.


Rich

Hey Rich,

Sorry if my posts were confusing. Yes, I did move the TFI Module back to the distributor. I have not put enough miles on it yet to be confident the stalling issue has been resolved. So far it has been running great *knock on wood*.

I have not tried installing new relays yet so I still have code 95. Hopefully, that is something I can get around to this weekend. Fortunately/Unfortunately my other Bronco project keeps me quiet busy.

I will make sure to keep this thread updated.

Good luck!

 

[DirtDonk]

Hey stock, did you apply some thermal paste to the TFI's mounting surface?
I'm only 90% certain at this point, but isn't that a requirement to help keep them happy?

If you did, great. But if you didn't, check with others regarding it's importance.

Paul

 

[stock74]

Hey stock, did you apply some thermal paste to the TFI's mounting surface?
I'm only 90% certain at this point, but isn't that a requirement to help keep them happy?

If you did, great. But if you didn't, check with others regarding it's importance.

Paul

Very good point. Thanks for bringing that up. Yes, I did apply a liberal amount of thermal paste.

If it is not a requirement it probably should be. Not applying thermal paste seems like a good way to overheat and burn up the TFI module.