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Discussion Starter #1 (Edited)
OK EFI gurus, need help here, or at least lead me in the right direction to sort the problem out. A littlet background first on the car so we wont have to address these questions later. Car is a 1983 factory 5.0, 5spd, A/C. Short block is a 30k mile engine from a 90 mustang. Running an E303 FMS cam, FMS/Crane blue 1.6 roller rockers, BBK equal leangth headers, C&L trueflow intake (with stock MAF at the moment), conical air filter. Stock 19lb injectors, intake, throttle body, etc. I recently bought an 87 5.0 AOD parts car to do an interior, and EFI swap. The 83 was GUTTED and all harness swapped from the 87. The trans harness, reverse harness, and O2's harness were properly swapped with manual trans pieces. The ECM is an A9L, and did the MAF conversion using the Interactive Systems and Technology kit. Car has speed control with VSS and FPM2 hooked up. No emissions components have been deleted: still running EGR and all associated components. Trying to get the car sorted out before I go in for emissions testing (gotta love Colorado), as well as driveability. I have not driven the car yet, as I havent had plates on it in years, and thats waiting on emissions. Car starts good, cold idle can be a bit rough, but smooths out good when warmed up.

Ran KOEO today for the first time, and heres what I came up with as far as codes. 54, 34, and 82.

Code 54: (fixed 10/20/12) I think I figured this one out tonight. The Air Charge Temp sensor appears to be at fault. If I jumper the ACT sensor at the harness, I get code 64. For more info on this , see ACT/IAT Codes 24/54/64 Troubleshooting I did an Ohms test at the sensor, and I get no reading at all, so it is stuck open. A new sensor tomorrow should fix that. and that is obviously the most serious code as that will affect cold start and can even send the EFI into closed loop failure mode. I'll update tomorrow after I replace the sensor.

Code 34: 34 - EGR Valve Position/Pressure Feedback EGR Voltage Above Closed Limit (O,R), PFE or EVP circuit has intermittently failed above the closed limit of 0.67 volts (CM). From what I understand, this can be a sticking EGR solenoid. I'll clean that tonight and report back. What else can this be??? Where should I look? I also understand code 34 can be very hard to pin down.

Code 82: 82 = (air diverter solenoid circuit fault) or (integrated relay control module). This is the one that confuses the hell outta me. The TAD and TAB solenoids are intact on the pass side firewall, plugged in, and the vaccum lines appear all correct and cant detect a vaccum leak. Where is this realy control? Is it the one on the pass side inner skirt by the air filter box area? Could it be faulty? What else should I be looking at for code 82?

If anyone has any other questions to narrow this down, dont hesitiate to ask. Thanks everyone.
 

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OK EFI gurus, need help here, or at least lead me in the right direction to sort the problem out. A littlet background first on the car so we wont have to address these questions later. Car is a 1983 factory 5.0, 5spd, A/C. Short block is a 30k mile engine from a 90 mustang. Running an E303 FMS cam, FMS/Crane blue 1.6 roller rockers, BBK equal leangth headers, C&L trueflow intake (with stock MAF at the moment), conical air filter. Stock 19lb injectors, intake, throttle body, etc. I recently bought an 87 5.0 AOD parts car to do an interior, and EFI swap. The 83 was GUTTED and all harness swapped from the 87. The trans harness, reverse harness, and O2's harness were properly swapped with manual trans pieces. The ECM is an A9L, and did the MAF conversion using the Interactive Systems and Technology kit. Car has speed control with VSS and FPM2 hooked up. No emissions components have been deleted: still running EGR and all associated components. Trying to get the car sorted out before I go in for emissions testing (gotta love Colorado), as well as driveability. I have not driven the car yet, as I havent had plates on it in years, and thats waiting on emissions. Car starts good, cold idle can be a bit rough, but smooths out good when warmed up.

Ran KOEO today for the first time, and heres what I came up with as far as codes. 54, 34, and 82.

Code 54: I think I figured this one out tonight. The Air Charge Temp sensor appears to be at fault. If I jumper the ACT sensor at the harness, I get code 64. For more info on this , see ACT/IAT Codes 24/54/64 Troubleshooting I did an Ohms test at the sensor, and I get no reading at all, so it is stuck open. A new sensor tomorrow should fix that. and that is obviously the most serious code as that will affect cold start and can even send the EFI into closed loop failure mode. I'll update tomorrow after I replace the sensor.

Code 34: 34 - EGR Valve Position/Pressure Feedback EGR Voltage Above Closed Limit (O,R), PFE or EVP circuit has intermittently failed above the closed limit of 0.67 volts (CM). From what I understand, this can be a sticking EGR solenoid. I'll clean that tonight and report back. What else can this be??? Where should I look? I also understand code 34 can be very hard to pin down.

Code 82: 82 = (air diverter solenoid circuit fault) or (integrated relay control module). This is the one that confuses the hell outta me. The TAD and TAB solenoids are intact on the pass side firewall, plugged in, and the vaccum lines appear all correct and cant detect a vaccum leak. Where is this realy control? Is it the one on the pass side inner skirt by the air filter box area? Could it be faulty? What else should I be looking at for code 82?

If anyone has any other questions to narrow this down, dont hesitiate to ask. Thanks everyone.

Code 82 could have something to do with the thermactor pins being in the wrong location in your computer. I just ran into that exact same problem.
 

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Discussion Starter #3 (Edited)
Ah, I didnt think of that. Hmmm, I thought I put those pins into the right # slots. I will have to double check that. I'll update later if that was it.

Edit: Additionally, when I pulled the air charge temperature sensor from the manifold, the entire little resistor probe inside the sensor was GONE. That about explained code 54. $16.19 for a BWD unit and code 54 is gone, better cold start, idle, rev, etc so far.
 

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34 replace BOTH valve and sensor, they wear together.

tab and tad, is from NOT repinning your 87 harness to 89 locations. as stated.
 

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Discussion Starter #5
Indy, Can i ask why you say that isnt a possibility? The instructions from Interactive systems and technology even say that if I didnt move those wires, I would get these codes. I did move them.....but its possible I re-pinned in the wrong postion? Can you clarify?

In reference to the code 34.....I have completely decarbonized the EGR, and I have checked it with vaccum, and the pintle moves easily and freely, it dosnt stick. The sensor on the other hand...it moves and "appears" fine, but I do not know the testign procedures for it. Is the EGR Position Sensor absolutly the problem?
 

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tab and tad need to be moved to pin 32 and 38

the maf a9l requires those locations, your sd harness is not pinned correctly.


past experience with egr, once you get the code 34, replace both the valve and position sensor, cleaning usually solves nothing.

where the pintle touches the valve is the source of wear.
 

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Discussion Starter #7
OK, after testing, the EGR valve position sensor (EVP) on the EGR valve IS faulty. So, when funds allow here soon, I'll replace both as a unit.

Also tested the TAB solenoid. There is ZERO resistance when checking Ohms under any setting, and the solenoid will not click (open) under battery power, so it is obviously faulty and will need replaced.

During this testing though, I discovered 2 things, one which is new, and likely MY fault/mistake. I also tried to activate the EVR solenoid with battery power. I had previously gotten a good resistance check there. After giving it power (it sparked) I know get code 84. So I obvously fried it. Its a solenoid recieving VPWR, shouldnt that have been ok? I dunno.
Then......and this has me stumped, and hopeing my ECM is not an issue: When I checked VPWR on the harness connections at the TAB connector, (with KOEO), I get a steady 5.05 volts. That should be at 10.5 + according to what I've read. Wondering if that may be part of the issue, i tested VPWR at the Canister purge valve KOEO. Same 5.05volts. Same at the EVR. WTF? My VREF seems alright. How and where do I trace the VPWR circuit? I am assuming I should locate the IRCM, and trace VPWR from there. But, if there is no VPWR from the IRCM, a no start condition is supposed to result. So, its likely a failure somewhere afterwards. I just have no clue where to start. So, if anyone has a good 87-88 MTA (managed thermactor Air unit, Tab/Tad solenoid) and EVR, let me know as these are no longer made, only the 89-93 which are different. I'd appreciate and tips on any of these, especially the VPWR.
 

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vpwr is pin 37 and 57 at ecm

I don't believe EVP has 12v source only 5v from ecm, hopefully you didn't fry the ecm.

You should consider getting an EVTM from helm publication.
 

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Discussion Starter #9
Yeah, I do need an EVTM. Cash short and strapped to get the car plated, emissioned and insured right now. What I'm going by right now is How to understand , Service and modify Ford Fuel Injection & Electronic Engine Control by Charles O. Probst, SAE. Its supposed to be the best breakdown of components, period.

The EVR (EGR vaccum regulator, right above the TAB/TAD) EVP and TAB/TAD are all recieving 5.05volt. The book says all recieve constant VPWR, and the groung is the switch. But.....I've also seen plenty of posts that say the EGR system is essentially turned OFF when EGR related codes start getting thrown. Maybe this is why only 5volt? I dunno...going to the JY tomorrow to pull a bunch of el-cheapo swap parts to give a quick try.
 

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power to those three circuits is made when the eec relay is energized in start or run.

fuse link G protects that circuit.

EGR is ignored when it is found faulty by the ecm.

EVP is not 12v powered.
 

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Discussion Starter #11
OK, a trip to the junkyard, a clean EGR/EVP off an 88 mark IIIV cleared code 34 away. All that is left is code 82. Havign a hard time find a TAB/TAD for an 87, as these solenoids changed in 88 to a different style. The search continues. PM me anyone if your partign out an 86-87 and have these. I can paypal you.
 

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Discussion Starter #12
Alright, UPDATE: The pin from the MAF conversion, that was supposed to be moved from pin 51 to 38 DID get put in the wrong spot, and apparently was the source of code 82. As soon as I moved the pin to location 38 correctly, code 82 went away.

Now, no codes in KOEO except 11 11. system fine.

But...In KOER, I still get code 44 adn 94. And from the research I've done so far, that means the oxygen sensors are NOT seeing a change in the air quality, air/fuel ratio when the computer is instructing the TAB/TAD solonoids to open causing air from the smog pump to be injected into the heads. WTF? So, my TAB/TAD solonoids check out during KOEO, but they are not opeing the bypass/diverter valve to let the air flow into the ports in the back of the heads. So, Either, the crosssover tube is blocked, which is highly unlikly since I thouroughly cleaned it when I installed this engine which has only seen a few hundred miles since, the smog pump is not putting out any airflow, the diverter or check valve is bad, or the oxygen sensors are bad. UGHHHH, kill me now!! Where do I start and whats most likely to be the cause? Anyone?
 

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Discussion Starter #13
Heres a few pics of what I'm working on. Shes not pretty yet (except those brand new 17 x 8 Cobra R rims that are authentic FMS pieces with zero miles and 24 45 17 Nitto 555's).
 

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Discussion Starter #14

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easy way to check the smog pump is just unhook the outlet to it and crank the engine up. if you feel air coming out, you know its sending air to the valves...

then you can just unhook the output from the front valve and trigger the solenoid to see if it then allows air to pass when triggered versus no flow when not. if you get appropriate flow, then solenoid likely bad...if none, then get a piece of tubing and hook to valve and suck on it to see if manually applying vacuum yourself opens the valve, if it doesnt, valve is bad.

same test for second valve/solenoid. if all checks out, a solenoid could have just been stuck from sitting. happened to me.

did you clean the ports in the back of the heads and not just the crossover tube?
 

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Discussion Starter #16
OK, the two valves (not solenoids) are capable of function. Smog pump is pumping air at its port. When vacuum is applied to the first valve (bypass), it sends air on to the diverter valve. When vacuum is applied to the diverter valve, the diverter valve it goes from heads to converter's fine. So I guess that eliminates the smog pump and valves as faulty. So, either my TAB/TAD solenoids are still faulty, though no codes for them anymore, an electical problem causign the solenoids to not be triggered, or a vacuum problem. Right?

My understanding is that the bypass valve should allow air by from the smog pump at ALL times, except under WOT (to lose parasitic drag). The Diverter valve sends air to the heads when the engine is cold, and when warmed up, to the converters.

So, where do I go and what to test from here?
 

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Discussion Starter #17
Almost forgot, teh ports on the back of the head "should" be fine, because the heads were completely rebuilt and 3 angle valve job done just a couple hundred miles ago. Unlikly they are carboned up that fast with a 30k mile short clock.
 

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put a vac guage at the end of the vac line to either valve.

apply 12volts to each solenoid, check guage.
 

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Discussion Starter #19
Yepp, thats exactly what I did this morning. Even though code 82 went away with the junkyard "new" TAB/TAD solenoids, the TAB was still faulty. The TAD solenoid would "click" and release the vaccumstore by the vaccum hand pump, the TAB solenoid did nothing. So......having 2 working TAD solenoids, I devised a plan. The TAD and TAB are functionally identical. THe ONLY difference is the connector plugs to prevent you from criss-crossing the wrogn connectors to the wrong solenoid. So I used the good TAD solenoid to replace the TAD, I had to fabricate an adapter harness to connect it to the TAB connector since they are different. KOEO 11 11. KOER 11 11. Cylinder balance test 9. Perfect! Thanks for the help guys! I'll update to let you know if I pass the emissions inspection and sniffer. Colordo is RIDICULOUS. Since this car is an 83, with a 90 engien and 87 EFI updated to Mass air, I have to pass first a visual inspection of all emissions components, then they hook up a scanner and make sure there are no emissions related codes and that all emissions components are functional. If I pass that, the I go on to the simulated driving "dyno" test. BS for an almost 30 year old car. F'ing nanny state!
 

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Heres been kinda what is givign me some tips/technical so far.

Bad Codes | Mustang Forums at StangNet
That's mine. Chased a lot of ghosts there until I found the real problem. The hand vac sure came in handy. It's been sitting for the summer, too hot to finish it. Supposed to be cooler next week, when this hurricane is gone.

Look how much has changed in 25 years: no distributor, no thermactor air, ODBII computers
Factory 5.0 rated at 225hp, now double.
 
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