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Discussion Starter #1
Last weekend I replaced coil and wires in my ´86 EFI. Now it hesitates and rattles during 3 or four minutes start up. After that it runs perfect so it looks that some component used during cold start up is not OK. Any suggestions.
Regards
Rodolfo
 

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First start with "pulling fault codes" from the vehicle computer and see what's indicated......for How to DIY, go here: www.fordfuelinjection.com for fault code numbers, explanations along with vehicle TEST connector location..

Additional info source www.broncolinks.com

Things to consider at cold start:

IAC = "idle air control valve" located on the right side of the throttle body can be removed and simply cleaned with TB cleaner, then check voltage levels.

ECT = engine cooling temp sensor located up front in an "ogtagonal shaped tree" threaded into the lower intake manifold between the FI plenum and distributor.....also has an upper throttle body cooling tube with rubber hose...

TPS = throttle position sensor located on the bottom of the throttle body, it's function is for "blade" angle....check for voltage issues.....

Check for fault code: 44 Thermactor Air System fault, this is a vacuum leak in the emissions system sucking air, my first suggestion from experience would be to go directly to the "Exhaust Cross Tube" bolted to the back of the cylinder heads and inspect that "check valve" on top of the tube....for rust and burn thru from extreme heat and moisture over time.....check valve costs around $20.00 from most auto parts stores or Pollution Control Industries, pciinc.com......

I'd check the FPR = fuel pressure regulator located on top of the fuel rail, right side towards the back, you'll need a fuel pressure guage to check for PSI...regulators are easy to replace....

The 86 BKO also has a "reservoir" fuel filter and canister located under the Transfer Case skid plate up on the drivers frame rail.....it has a pressure valve in the top of the canister to keep it full of fuel for cornering and extreme Off Roading angles so the forward fuel pump isn't "straving", if the pressure valve is malfunctioning fuel will not flow beyond that point..


That should keep you busy......lol lol....for awhile, let us now what you find out.......

Good Luck ~ :thumbup
 

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Discussion Starter #3
Jean, thanks for your support. I did this before posting my thread:

1.- Cleaned/replaced IAC (I had a spare one)
2.- I have a fuel pressure gauge installed (I had fuel pressure issues some time ago) and pressure is good and steady when problem occurs, so I don't think I have pump/reservoir/FPR issues.
3.- Checked hoses to the air pump, they are OK.
4.- No codes pulled, "Mea Culpa", I'll write 100 times "The first thing to do is to pull codes" and use my wife's Fiat for a week as punishement (I am 1,8 m and 115 Kg so that is really a bad thing....), but before doing that, I'll pull codes......

Do you mean the PCV Valve?

I´ll check ECT and let you know.
Regards
Rodolfo
 

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Discussion Starter #4
Codes:

This is what I found:

KOEO, path code 11 and in memory

14, PIP circuit failure
18, SPOUT circuit failure, grounded.

KOER

34, EGR failure
41, HEGO sensor voltage low (Lean)

Which one can cause malfunction ONLY during startup?????
 

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* PIP = profile ignition pickup or Hall Effect sensor is located on the distributor shaft so you'll need to pull out the dissy to replace it as it has a collar and sldies off, this would be my FIRST guess because it's tied to the ignition, TFI = thick film integrated ignition module located outside on the distributor...AND IDM = ignition diagnostic monitor which is nothing more then a resistor in a big green rubber case, like an eraser with this symbol on the side .....W.....it's located on top around the drivers valve cover or coil area.....it's a 2 wire circut off the thicker part of the harness.........costs about a dollar each ....at www.fordfuelinjection.com you need to solder it in etc...

spOUT = spark output would affect timing, remember you have to unplug it to time the engine....it's a 2 wire circut......the male part of the spOUT can be found in some ABS systems, I got one from Steve83 that I've been using it for some time.....don't know if you can go the junkyards where you are BUT www.fordfuelinjection has the "Weather -Pak" style for a couple of bucks and just solder it in...

EGR = exhaust gas return, so it's either the EGR valve not opening OR.......*the EGR sensor on top of the valve is failing, easy to test...

HEGO is the O2 sensor which reads the exhaust gases in the header and tells the PCM = power control module, vehicle computer to run either lean or rich, they tend to become less effective from extreme heat over time and richen up the system....life cycle is 30k miles then replace.....

PCV = positve crankcase ventilation (filter) located in the top rear passengers side valve cover and up to the back of the fuel injection plenum with a vacuum hose....there's another one starting in the oil filler cap, drivers side valve cover going up and inside the air filter box on top....easy to replace....

There was a Ford recall sometime ago where the PCV hose to the FI plenum (back) this set up was leaving gases in # 4 & #8 cylinders causing problems etc....so take the brake booster vacuum line from the top of the FI plenum and route it to the back of the FI plenum where the PCV hose goes and then run the PCV hose up on top where the brake booster vacuum line goes and you're good to go....check my video at www.supermotors.net/17406, it's in there somewhere OK....

Good Luck ~ :thumbup
 

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Discussion Starter #6
As an update, yesterday my truck started rattling and coughing not only during start up but also after driving downtown whet she got hot. Tired of this I decided to go back to the old Accel coil that I replaced and.....voilá !!!! running perfect all the time, starting perfect and no problems when hot !!!! The new (out of the blister) MSD coil was bad.....
 

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Was it the red unit? Said made in china on the package?

Had the same problem chasing a hard start/running rough on my F350/351. ended up buying a good quality coil from carquest to replace the MSD coil i got from Advance.
 

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Discussion Starter #8
Made in USA, part number 8227, I can´t belive such a bad luck, I bought the best coil I can, payed shipping + taxes (total 100 U$S) and the lousy coil doesn´t work.....:banghead:banghead:banghead
 

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I've been (knock, knock) using MSD for some time now and not experienced any problems like yours, it's unfortunate today the most companies don't spend enough time for quality control, it's just all about make it, ship it......sorry to hear that....:rofl:

Make sure you have nice high temp heat resistant ignition wires......my # 5 & 6 used to burn thru on the boot bottom causing arcing...due to the poor OEM design in the cast exhaust header there.....now I use Blue 9mm FMSR wires and I'm good to go and they're not expensive around $50.00 or so....:rockon

Glad you got it running better Brother ~ :rockon

Good Luck ~ :thumbup
 

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Discussion Starter #10
Thanks Jean, I use 9mm ford racing wires, so far so good. I´m also very careful while routing them, used several wire fasteners to keep them in place under off road conditions. I swap to shorties a couple of month ago so I have some more room for the wires. I also replaced cap and rotor this time together with wires and coil, a sixlitre tune up including re gaping plugs and timing.
Regards
Rodolfo
 
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