'95 4.9 F150

[111JESUS]

Well, I'm trying some stuff I probably shouldn't be... but I've about priced myself into it now... so here goes. And I'll try to get to the point quickly.

My 300 is an EFI and I'm attempting to convert / use a conventional ignition system, albeit a HEI distributor. I have installed the distributor and used the pos voltage wire from the original coil to power on/off the new system. Doing so I figured to signal the ecm via the tach terminal on the distributor cap. I have determined that this circuit does feed thru the ecm to the fuel injectors, as that power to injectors disappears when the tach wire is disconnected. However I have also found that when cranking, the voltage on the tach wire exceeds 30 volts...? So I am suspicioning that this is the wrong voltage to control the injectors...? Any ideas? Injector actuation voltage? Or suggestions on keeping ecm control of injectors along this route or just delete it as well and go ahead and convert from throttle body to carb...
Oh... it is a fuel issue as it will start and idle on a touch of brake clean.

Thanks in advance. Michael

 

[bubba22349]

Hi Michael and welcome to the Ford Six forum. A stand alone HEI Distribitor needs a full 12 volts of key switched power to operate it. The stock ECM controls the fuel injectors on / off switching and the amount of injector pulse width by its on board fuel maps. The ECM also controls the stock TFI Distributors timing advance by its on board timing maps. The ECM also needs info from the engine sensors for tempature, cam shaft timing, the EGR, the throdle body, and probally a couple others that I am not thinking of right now. I don't see how you going to be able to use an HEI Distribitor with the stock ECM and EFI. Best of luck

 

[pmuller9]

Welcome
You are correct. The HEI distributor will not provide a clean signal to trigger the ECM for fuel injection.

If you use the HEI distributor without recurving the mechanical advance you will damage the engine.
The EFI 4.9s have a fast burn head that requires less total ignition timing and a shorter advance curve.

Since the ignition timing is no longer controlled by the ECM you lose detonation protection from the knock sensor.

The ECM is no longer getting the IDM signal to detect misfire.

The 1995 stock TFI ignition is a dwell controlled system that is far superior to the HEI system especially for low rpm engines.

 

[111JESUS]

How feasible is the idea to remove throttle body and fab an adapter body for a carb? Not familiar with the signal method to injector style carb... if I go that route... does that carb normally have it's own throttle sensor & is that how the inj.s get it's/their signal? Basically I would be "old schooling" the engine I suppose. Any idea of last f150 year model using carb system?

 

[pmuller9]

It is possible to use the lower half of the EFI intake with a fabricated plenum for a throttle body injection system like the Holley Sniper.
However the HEI distributor will not supply a signal to work with any injected system be it port injection or throttle body injection.
The HEI distributor is not a good choice for a low rpm six cylinder engine in any case.

The last year for a carburetor engine is 1986.

Why are you wanting to make these changes?

 

[111JESUS]

It's an old beater truck that circumstances are tying me to... after 3 transmissions in a short time jerked it out and converted to manual with parts out of a junk donor truck I have. 20 miles later the engine goes to derate, uturn & it did get me home... barely. Could not get the ecm to blink code or my mothballed obd1 ford plugin to pull codes... theorized the open circuits from the transmission harness were constant "hard" or ecm was just not giving them up. So I start going by symptom swapped throttle sensor, no...
maf sensor did help idle start and incremental throttle response but no driveability. Vacuum was very low idling 5-8 lbs... started checking timing, valves etc, finally located sheared drive gear pin on distributor... 1st for me but eventually realized because timing is geared that was weakest link... also a firm twist on dist rotor & it moving about 45* gave me a clue. Replaced the pin etc... started and never could get the engine to respond with any power, timing just would not advance, up/down properly. All the conflicting info to the ecm I'm sure. So I get the bright idea to go hei and see if the ecm would accept the signal off that system to operate the injectors. I was not real hopeful but willing to try as a 1st step towards operating again. I was reading here on this forum re: fabbing own adapter to use carb. That is what prompted the hei idea anyways, that if ecm wouldn't accept the signal, I would just go ahead and delete it and continue back to old school. I ain't looking for an explosive quarter horse, just a steady dependable shetland pony will be great. I use it as an old work truck and per the course time effort & $s I've now put in it I probably could have bought another running beater.

So, my idea was to simply unbolt the present throttle body, fab an adapter and install on present plenum... no bueno?
Thanks for the info re: carb style TB being a bad idea.

 

[111JESUS]

On my re read of your post, I caught "the hei not a good choice for...". Why is that? I was thinking a stronger spark would be good as long as I was changing it out.
Not a newbie wanna be, been wrenching 45 plus years but mostly on heavy trucks, trailers and such. Never much automotive & certainly not a convert like this... that's why I'm reaching out for advise. thnx

 

[pmuller9]

The modules that are used in the HEI system are current regulated between 6 and 8 amps.
When used in a low rpm six where there is a lot of time between spark, both the module and ignition coil stay saturated at that current for long periods of time.
The extra heat in the coil reduces spark and shortens coil life.
The module life is also shortened.

The stock system you replaced has dwell control which keeps the dwell time constant and prevents long periods of current saturation.
Since the dwell time is controlled the coil charge current can be higher and outperforms the HEI system.
You actually took a step down.

The MSD system is not limited to a coil charge current and produces a spark with a much higher current than any of the street level inductive discharge ignition system.

 

[pmuller9]

If you are going to stay with the HEI the mechanical advance needs to be shortened.
The HEI comes with about 26 degrees of advance which will advance the timing from 10 to 36 degrees.
The EFI engine will have detonation if the total timing is much more that 30 degrees.
The mechanical advance should be shortened to 18 degrees so you can have an initial timing of 12 degrees BTDC and a total timing of 30 degrees.
You will also need to use a standard non EFI carburetor.

There may be another possibility.
Does your harmonic balancer have the 3 tooth wheel on the back?

 

[111JESUS]

Just walked out to double check... no sir. No ring.

If I'm following you correctly re: reducing the mechanical advance... do you mean changing the advance on the vacuum diaphragm etc...?
I read a reference on paper shipped with distributor alluding to a hex key adjustment somewhere... it was not very informative. But you are certainly teaching me things to look & prepare for...

What would you recommend on carb...? 2 barrel and ??? CFM? Or? Would a 4 barrel off an old 351 overwhelm it?

The timing index on pass side, is the deep v 10* or 12*? There's 6 tips but 4 small v's from the circle to the deep V.

I appreciate the advise and info you are extending me as I attempt this modification. If I get this thing running smooth and dependable and able to untrack itself down the road I will be more than satisfied! And will have learned new stuff to boot. If I had not shied away from the automotive side over the years ... I suppose I would have alot of this gasoline knowledge by now... ha,ha... on me. Seeing as how the HD has went all stupid with DEF, DPF and a conflagration of other acronyms. All electronification... who would have ever thought dumping straight up exhaust soot directly back into a supposedly "pristine" intake, combustion chamber was going to be a good idea? Think of the metallurgical innovations there had to be to get a million mile engine, before o/h with such filth being sucked into it! Might as well throw the air filter away .

 

[111JESUS]

Just walked out to double check... no sir. No ring.

If I'm following you correctly re: reducing the mechanical advance... do you mean changing the advance on the vacuum diaphragm etc...?
I read a reference on paper shipped with distributor alluding to a hex key adjustment somewhere... it was not very informative. But you are certainly teaching me things to look & prepare for...

What would you recommend on carb...? 2 barrel and ??? CFM? Or? Would a 4 barrel off an old 351 overwhelm it?

The timing index on pass side, is the deep v 10* or 12*? There's 6 tips but 4 small v's from the circle to the deep V.

I appreciate the advise and info you are extending me as I attempt this modification. If I get this thing running smooth and dependable and able to untrack itself down the road I will be more than satisfied! And will have learned new stuff to boot. If I had not shied away from the automotive side over the years ... I suppose I would have alot of this gasoline knowledge by now... ha,ha... on me. Seeing as how the HD has went all stupid with DEF, DPF and a conflagration of other acronyms. All electronification... who would have ever thought dumping straight up exhaust soot directly back into a supposedly "pristine" intake, combustion chamber was going to be a good idea? Think of the metallurgical innovations there had to be to get a million mile engine, before o/h with such filth being sucked into it! Might as well throw the air filter away .

Typo... 5 tips.

 

[pmuller9]

The hex key is for the vacuum advance adjustment.

The mechanical advance is a set of weights and springs and a center plate that is under the rotor in the distributor.
Normally the amount of advance is changed with a different center plate and weight combination.
For 18 degrees of advance you would use a #438 center plate with a #139 weight.
The problem is I don't know where to get plates and weights.

The one solution is to install a limiting screw and use the screw head to make adjustments as shown on the left.
Before looking at any of this you need to try the distributor first using a timing light to see how much advance it presently has.

Each of the tips on the timing tab are 2 degrees.
If you clean off the timing tab the bottom of the deep "V" should be marked "10" degrees which is where the stock 4.9 is timed.

 

[pmuller9]

A 350 two barrel or a 390 to 450 cfm 4 barrel with a vacuum secondary will work with a stock engine.

Here is one of the latest EFI lower intake manifold fabrications for a carburetor.

All Big Six - Fabbing intake on efi lower.

Look for advice feed back your crazy kinda stuff. Am I on track? Carb or sniper will sit Level im unsure how high to put the carb mounting surface. Was thinking 2" but that seems high. Now thinking to put it at 1" Also wondering about hood clearance. Rig is a 76 f150 But 1" seems to be...

fordsix.com

Eventually the fiber timing gear on the camshaft will fail.
You may want to replace it with a metal gear set.

 

[111JESUS]

1st 300 I've owned, only knew it was gear timed from block parts blow up picture I found somewhere on web. Didn't know it had a fiber gear.
Read the whole post you referred me to. Quite interesting.
I'm going to try what I have in mind following the lines of info you've given me.
Mechanical advance... my recognition terminology... centrifugal advance (which is almost what I asked you to confirm to start with). If I need to go the bump screw option... you have a general idea of % increase of spring load needed over what's in distributor now? 10, 15, 20%?
If my idea works I'll pixelate it and post when done... if not, truck may show up as a hunk of burned up shell....

 

[xctasy]

You can do downward compatible changes to OBD1.5/ EECIV/ EFi vehicles. Key thing is you have to know what the EECIV is looking for, and how to continue signal supply. This is easy IF you know what the system is looking for. When you convert to auto, the KOER trigger from the manual gearbox is not engaged, so you cannot read On Board Diagnostic 1.5 (1990 -1995 truck SAE mandated Dealer Trouble Codes) . Ford ensures you can jumeet the EECIV, because the same computer serves many diverse kinds of vehicle. 4 to 12 cylinders, Central Fuel Injection, Bank Fire Port EFi, Sequential Port, MAP Speed Density, MAF Hot Wire, VAM Air meter, Thick Film Ignition, EDIS 6 or 8 semi coil pack, Turboed, SuperCharged, Variable Valve Timing, Broad Band intake manifold tracks, Factory LPG and Gasoline Dual Fuel...the engineers are used to being shot gunned by feature creep from Marketing or Finance or Emissions.

A downward non- compitable change is, say, a triple carb conversion, or an HEi, Duraspark I/II/III ignition.

A turbo or supercharger is an upward change.

All are compatible if you've done your homework and know where to raid the right 60 pin computer pinout schematic. And where to get a sensor to provide the constant data need so the system won't Shut Your Clydesdales down.

I'm on my fifth Toyota RAV4.1 to Ford triple carb six cylinder EECiV conversion. I use the stock Ford computer with Toyota wiring, and a mixture of Essex 90 V6 and Duraspark III sensors. Fords EECIV has many non negotiable's, but it's really easy to make a non standard ignition work with your 1995 if you are aware of what the EECIV is looking for. I help people with MegaSquirt Scoping. A lot of times, people see sense and keep the stock Ford labyrinth of wires and systems, and just trouble shoot them. Unlike others, EECIV or the earlier 1978 to 1983 systems....they don't faze me at all. I grew up surrounded by good automotive engineers who realised that it's easier to deal with systems rather than do a frontal labotomy.

1. The Start Dealer Trouble Code ( OBDI.5 two earths) or ( on Mustangs) the defacto OBDII port for 95 V6s has to be able to work the KOER codes, so anytime you do an auto conversion to a vehicle born stick shift, the whole O2 harness and clutch lock-out goes west, which is why you can't read codes.

2. The Solid State Ignition has to be incrementing and proving response to the EECIV. Spark Out and Spark In and the signals that phase injectors or log ignition pulse have to be sent to the EECIV.

3. The Thick Film Ignition or Base timing SPOUT has to respond to executive commands. Fuel and Spark and Push Start Inductive Control Modules have different base rpm start points, with idle tip in and Barametric MAP cold start ignition timing changes.

4. Ford use either Idle Solenoid Control or what GM call an IAC. Some earlier carbs use five other devices including the humble old choke and vacuum operated throttle modulator, ad well as A/C and Throttle Solenoid Positones, as well the TPS. Base idle settings vary between type, and the Air Control metering devices can be one of four types. Turbo cars have a 3 bar MAP sensor and a MAF sensor. So the whole shooting match is mapped out with satraps and sentinals and a sagelog of settings is compiled against three air, water and EGR and AIR sensors.

5. EGR is automated with all EEC computers, but it can be done manually with the older carb based ssystems. EEECIV "sagelogs" the settings with an electronic DPFE valve sensor.

6. The open and closed loop fuel values from the pulse width modulation signals sent to the injector solenoids complies a vast list of Keep Alive Memory to slew the fuel delivery within in charted limits.

7. The Fuel pump circuit for all EFi Fords varies for 1995s, but HI and Low Perspire pumps are controlled by a relay system which ha's complicated checks and balances for pressure and return flow, with a notoriously difficult fly tongue pickup with a throublesone earing process.

8. For a genreal lookup of parts, I have a 103 item list of Vehicle Emissions Component Identification names, mostly for the 1978 to 1995 cars. The peak of components were the 1985 4 bbl 5.0 Mustangs without Feedback carbs. Your 1995 ha's only about 65 items. By 2003, it was down to 39.

 

[pmuller9]

However the HEI distributor will not supply a signal to work with any injected system be it port injection or throttle body injection.

I stand corrected.
The instruction shows the yellow wire from the Sniper going to the Tach terminal of the HEI distributor.
I would still call the tech department just to be sure.

 

[111JESUS]

Any estimate of advance degrees gained thru the vacuum advance?

 

[111JESUS]

XtaC... I read every word you posted... I understood: "You can do..." and my brain fried. Did you suck that up and spit it out spontaneously?

 

[xctasy]

This post is similar to King_Kong in that you both have OBD II or similar 1995/1996 trucks. If MegaSquirt, EECIV, EECV, Sniper or FAST or Fitech or even a decontented step back in time to a carb, or adding a turbo, supercharget or Nitrous, you can make anything go with anything.

 

[bubba22349]

Just walked out to double check... no sir. No ring.

If I'm following you correctly re: reducing the mechanical advance... do you mean changing the advance on the vacuum diaphragm etc...?
I read a reference on paper shipped with distributor alluding to a hex key adjustment somewhere... it was not very informative. But you are certainly teaching me things to look & prepare for...

What would you recommend on carb...? 2 barrel and ??? CFM? Or? Would a 4 barrel off an old 351 overwhelm it?

The timing index on pass side, is the deep v 10* or 12*? There's 6 tips but 4 small v's from the circle to the deep V.

I appreciate the advise and info you are extending me as I attempt this modification. If I get this thing running smooth and dependable and able to untrack itself down the road I will be more than satisfied! And will have learned new stuff to boot. If I had not shied away from the automotive side over the years ... I suppose I would have alot of this gasoline knowledge by now... ha,ha... on me. Seeing as how the HD has went all stupid with DEF, DPF and a conflagration of other acronyms. All electronification... who would have ever thought dumping straight up exhaust soot directly back into a supposedly "pristine" intake, combustion chamber was going to be a good idea? Think of the metallurgical innovations there had to be to get a million mile engine, before o/h with such filth being sucked into it! Might as well throw the air filter away .

Hi 111JESUS, in reading your above posts again I am wondering if you were using the right timing mark there are two one is a large square grove (about 3/16 of an inch) the other is a thin V line this second is the one you use with your timing light to time all these era Ford engines V8 or Six'es. I had some trouble figuring this out when I first bought my 1994 F150 4.9 years ago before that I had only had the older carb 240 & 300 engines. Then other thing that was different was that on the EFI you needed to unplug the Spout conector too before trying to set the base timing. You can find all this info in this link here.http://www.supermotors.net/registry/media/833750
Anyway it's probally to late unless you wanted to put back in your orginal TFI distributor. X3 these EFI engines because of their fast burn combustion chambers don't want or need all the advance timing that the HEI Distribitors and other will have built into them. I have been helping a couple other site members trying to tune them and we found the same thing 10 degrees base timing and about 16 to a max of 18 degrees of advance, still have not found out how much vacuum advance can be used for steady state cruse speeds but it won't likely won't be very much if any. One is using the Sniper 2300 and the other is using a carb both are using the carb intakes, it's a lot of work to get them right and to me it is probally easier to stay with all the stock EFI system parts. Chargeing parts on mine wasn't an option anyway since I used to live in Southern California and it had to meet both look visually stock as well as the the emissions tail pipe testing but still I was able to get my 1994 running perfectly with a personal best of 22.5 MPH on a very long trip. Best of luck