EFI Help Missing and Surging

[Eads74bronco]

So I finally got the EFI setup together and it's been running great. Drove it about 200 miles this weekend and had no issues. Monday drove it to work and ran great, went out at lunch and it surged and missed while accelerating. Took it to Oreilly's and used the scanner and came up these codes.

KOEO 81, 82, 85, 84, 29, & 33. which all of these are ok with my setup
KOER 12, 44, 33, and Cyl 8 Not sure what all causes the code 12 or the cyl 8

Went home and did the self test and came up with
KOER 12, 94, 44, 33, 18

Cylinder Balance self test
1st test showed Cylinder 7
2nd test showed Cylinder 4 & 7

Checked and the SPOUT is connected

I'm assuming since this all happened at once that it's one problem causing the rest. Any ideas? Bad TFI?

 

[airbur]

Pull the spout and check the timing. Should be at 10BTDC.

 

[Eads74bronco]

If it was running and starting good hot or cold would the timing be off to far all of a sudden? I'm going to have to make some marks and do something different to check it because I changed the water pump and I can no longer see the marks and the pointer isn't on the motor anymore either.

 

[NYLES]

buy a digital timing light then all you need to mark is 0 and use something as a reference

but I dont think timing is your problem unless you didnt tighten down the dizzy and it finally moved

 

[Eads74bronco]

buy a digital timing light then all you need to mark is 0 and use something as a reference

but I dont think timing is your problem unless you didnt tighten down the dizzy and it finally moved

I'll have to get one and check it. The dizzy was marked and looks like it hasn't moved.

Noticed that you have a similar setup to mine 5.0 EFI and ZF but I'm going to a 35" tire any gearing recommendations? I'll be driving on the highway a lot and some trails.

 

[ransil]

Check the spark plug & wires

Sent from my Galaxy Nexus using Tapatalk 2

 

[TwoDalesDad]

Just how many miles were on this engine before your bronco? .....Sounds like it may have skipped a tooth...

 

[NYLES]

430s aint enough Im 1/2 way to 513s on both ends.......thats why I love the ZF Id go least 488s punch ya #s in that itll tell you what to do.........really you can run some serious gearing thanks to that 5th gear and still hit the interstate at under 2500 rpm

http://www.grimmjeeper.com/gears.html

 

[texhost1]

I had a gremlin on my efi set up. It would mis and backfire sporadically. The problem what the solid state piece that attaches to the side of the distributor. I used a used distributor. I finally diagnosed it by tapping the side of the electrical part and spraying it with water while running the truck. The tapping and the heat change would trigger the failure. You might try that.

 

[NYLES]

I had a gremlin on my efi set up. It would mis and backfire sporadically. The problem what the solid state piece that attaches to the side of the distributor. I used a used distributor. I finally diagnosed it by tapping the side of the electrical part and spraying it with water while running the truck. The tapping and the heat change would trigger the failure. You might try that.

Known failure part and worth having 2

 

[Tito]

Interested to see what you find. I am having similar issues all of a sudden with mine. Same KOEO codes. Seems the warmer mine gets the worse it runs. Idles fine but any throttle and its a circus.

 

[NYLES]

go get that lil dizzy module Tito if thats not it youll need one one day.....they get warm plactic expands loses all it circutr runs like carp or quits all together

 

[Tito]

I have swapped dizzies including the tfi, tried new tps, new maf, computer, and TB. (Have them on shelf). Need to swap ECT and check my 02s. Just changing one at a time basically. I had recently replaced wires, plugs cap and rotor and ran fine afterwards. Sat for a couple months over winter with occasional drives and now bleh. I also have a set of rebuilt injectors to throw in.

 

[Viperwolf1]

So I finally got the EFI setup together and it's been running great. Drove it about 200 miles this weekend and had no issues. Monday drove it to work and ran great, went out at lunch and it surged and missed while accelerating. Took it to Oreilly's and used the scanner and came up these codes.

KOEO 81, 82, 85, 84, 29, & 33. which all of these are ok with my setup
KOER 12, 44, 33, and Cyl 8 Not sure what all causes the code 12 or the cyl 8

Went home and did the self test and came up with
KOER 12, 94, 44, 33, 18

Cylinder Balance self test
1st test showed Cylinder 7
2nd test showed Cylinder 4 & 7

Checked and the SPOUT is connected

I'm assuming since this all happened at once that it's one problem causing the rest. Any ideas? Bad TFI?

These are the only codes of interest.
12 - RPM Not Within Self Test Upper Limit (R), Idle Speed Control motor or Air Bypass not controlling idle properly -generally idle too low
18 - Spark Out (SPOUT) Circuit Open (R), Loss Of Ignition Diagnostic Module Input To PCM/SPOUT Circuit Grounded (M)

For code 12, look at the IAB. It may be gunked up inside and not able to control idle speed well. Some IABs don't like to be mounted upside down.

For 18 you may want to test the harness for continuity from pin 2 of the TFI connector to pin 36 of the ECM connector. It could be a harness problem and this will tell you if it is. Other possibilities are TFI and ECM failures. What harness is it?

 

[Viperwolf1]

I have swapped dizzies including the tfi, tried new tps, new maf, computer, and TB. (Have them on shelf). Need to swap ECT and check my 02s. Just changing one at a time basically. I had recently replaced wires, plugs cap and rotor and ran fine afterwards. Sat for a couple months over winter with occasional drives and now bleh. I also have a set of rebuilt injectors to throw in.

Are you still running the explorer MAF sensor?

 

[Eads74bronco]

These are the only codes of interest.
12 - RPM Not Within Self Test Upper Limit (R), Idle Speed Control motor or Air Bypass not controlling idle properly -generally idle too low
18 - Spark Out (SPOUT) Circuit Open (R), Loss Of Ignition Diagnostic Module Input To PCM/SPOUT Circuit Grounded (M)

For code 12, look at the IAB. It may be gunked up inside and not able to control idle speed well. Some IABs don't like to be mounted upside down.

For 18 you may want to test the harness for continuity from pin 2 of the TFI connector to pin 36 of the ECM connector. It could be a harness problem and this will tell you if it is. Other possibilities are TFI and ECM failures. What harness is it?

Its an RJM only a couple months old.

 

[Eads74bronco]

I have swapped dizzies including the tfi, tried new tps, new maf, computer, and TB. (Have them on shelf). Need to swap ECT and check my 02s. Just changing one at a time basically. I had recently replaced wires, plugs cap and rotor and ran fine afterwards. Sat for a couple months over winter with occasional drives and now bleh. I also have a set of rebuilt injectors to throw in.

Mine's doing the same, gets worse as it warms up. I really don't like the sounds of what you've had to do. I hope I don't have to try all those, I don't have them on the shelf. Been doing some reading on the mustang forums and saw a couple people with similar issues and it was the dizzy.

 

[Tito]

Yeah I was thinking dizzy as with spout disconnected the idle timing was all over the place. Swapped in new dizzy and it read right at 10 but had same issues.
I am still running the explorer MAF.

 

[Viperwolf1]

I am still running the explorer MAF.

Find a MAF sensor with number F2VF-12B579-A2A. It works much better than the explorer sensor with 19 lb injectors and a stock '89-'93 mustang ECM. It will need to go into a stock 70mm housing, just like the explorer. You can find them in these applications.

Mustang 94-95 F2VF-12B579-A2A
Mustang GT 94-95 F2VF-12B579-A2A
Mustang Cobra 94-95 F2VF-12B579-A2A
Crown Vic 92-94 F2VF-12B579-A2A
Town Car 91-94 F2VF-12B579-A2A
Grand Marquis 92-94 F2VF-12B579-A2A

 

[Eads74bronco]

Tried a new TFI and as soon as it warmed up it started surging again.