EFI to carb conversion
#31
Since your screen name would suggest you are a MOPAR fan, try replacing plugs on a hot B-block MOPAR engine, then take off and measure the #7 plug wire, oh and while you are at it, try to salvage the small plastic insulators that keep the 7' long POS off the exhaust manifold. Brakes on a MOPAR, better carry the shoes with you.
Now we shall address brand C, Distributor on the back, almost inaccessible, plugs under the manifolds for years, a front mounted BEHIND the water pump distributor that a seal leak takes out, an engine that was a OHC 4 cyl Briggs and Stratton. Chevette, with A/C the compressor had to be taken loose the get the distributor cap off, but if the little roller skate had PS, it wouldn't come off till you raised the engine. HEI system, I got rich changing modules, caps and rotors on them. Ford moved the TFI to the fender due to heat related issues.
Then there were Pontiacs, on the breaker point distributors, opening the window (buried down low) and trying to plug in the Allen wrench was good for getting knocked on your butt.
FWIW, I have known and still do many excellent mechanics, including the gentleman who built my new 460. Wiring to most of them is a black art and they do not have the expertise or patience to sort it out. Due to labor costs, most customers do not want to pay the time it takes to go through a wiring harness, hence the usual warranty method, replace it rather than go into it.
I have completely redone my truck from a carbureted 460 with C6, to a very uncommon MAF/SEFI system and using an E4OD. Yes, I had some issues, but wiring does't scare me or faze me, dad was an electrical engineer with a masters degree from MIT, I spent 4 years in a Mercedes-Benz, Dodge, Jaguar and MG dealership and you have not seen electrical problems till you have worked on Jaguars. Every Jag mechanic needs this:
Now we shall address brand C, Distributor on the back, almost inaccessible, plugs under the manifolds for years, a front mounted BEHIND the water pump distributor that a seal leak takes out, an engine that was a OHC 4 cyl Briggs and Stratton. Chevette, with A/C the compressor had to be taken loose the get the distributor cap off, but if the little roller skate had PS, it wouldn't come off till you raised the engine. HEI system, I got rich changing modules, caps and rotors on them. Ford moved the TFI to the fender due to heat related issues.
Then there were Pontiacs, on the breaker point distributors, opening the window (buried down low) and trying to plug in the Allen wrench was good for getting knocked on your butt.
FWIW, I have known and still do many excellent mechanics, including the gentleman who built my new 460. Wiring to most of them is a black art and they do not have the expertise or patience to sort it out. Due to labor costs, most customers do not want to pay the time it takes to go through a wiring harness, hence the usual warranty method, replace it rather than go into it.
I have completely redone my truck from a carbureted 460 with C6, to a very uncommon MAF/SEFI system and using an E4OD. Yes, I had some issues, but wiring does't scare me or faze me, dad was an electrical engineer with a masters degree from MIT, I spent 4 years in a Mercedes-Benz, Dodge, Jaguar and MG dealership and you have not seen electrical problems till you have worked on Jaguars. Every Jag mechanic needs this:
#32
My Ford has two or three wiring diagrams for the same truck. TFI on the firewall, TFI on the distributor, etc., etc.
You even need to pop the inner fender out in order to change the ECU, or as Ford had to call it, the PCM.
I have spent $500 trying to fix the EFI/TFI system and in my estimation would need a new wiring harness for approx. $1000.
And that doesn't include the crazy vacuum controlled side of things. Most were very helpful like, is there gas in the tank. Like you said, this forum is out of date and mostly irrelevant.
which many on this forum attribute to EFI's inefficiency and poor gas mileage. Later Ford decided to modify the same system to create the SEFI system. Something that other companies had been doing for decades.
My 1990 Lexus LS400 is batch fire, and that's a 32V DOHC Aluminum V8 in a car that cost $39,000 in 1989 - or $72,000 today. If batch-fire is good enough for one of the finest luxury vehicles ever made, it's good enough for my pickup truck. Also, FYI, the Mustang 5.0 was SEFI as early as '88.
For that matter, why even create the half way to SEFI EFI system when most others were using throttle body injection with similar gas mileage results? No one can answer that except the propeller heads at Ford.
#33
#34
That's the best you guys can come up with? 1990 model year vintages? Really? I was talking about foreign vehicles. My point about the 8 PIP signals was why use the signals for the ignition and then not for the fuel injection side. There are many sites showing how to convert from EFI to SEFI for a reason. If you had half a brain you'd realize that you are arguing against yourself. On the one hand you are questioning why go from EFI to a carb and then on the other you are trying to justify that EFI was used by many manufacturers in the 90's. No kidding, really? What's your next argument, that the rope grips on the back of the front seats in the 50's were fine and that seat belts are overkill? No, it's a progression and I'm sorry, but the technologies of the 90's are inferior to those of today. So why would I want to spend thousands of dollars trying to revive old outdated technology for a truck used to make dump runs? And you are making my point when you start in on other manufacturers engineering crazy scenarios. Most manufacturers have these shortcomings, including Ford. If you don't think so, try unplugging a single suspected stuck injector from a 5.0L EFI on the passenger side. But that upper intake sure looks sexy. Now I know that the design was intended for the low profile hood of a Mustang, but given Ford's proclivity to make mid year design changes and the fact that an F150 is a utility vehicle that has room for tunnel ram under the hood, you'd think the engineers at Ford could have come up with a more serviceable design. Thankfully the new models have finally addressed that one.
#35
Since you are so hot on foreign vehicles, why don't just real fast slap a water pump on a Benz diesel with A/C or perhaps an alternator a Jag XJ12/XJS? Maybe plugs on the later Jag HE version. While you are talking reliability, yes many Asian imports have great records, but they have Achilles heels too, timing chain tensioners on a number of Nissan and Toyotas, how about the timing belt on many Japanese vehicles, originally no service interval specified, how many Hondas ended up needing major engine work.
As for the intake on the Windsor block truck engines vs the Mustang (also the Crown Victoria, Grand Marquis and Town Car) you obviously have never seen the latter or you would not make that statement. Ford decided in mid 1985 to use that long runner intake on the truck engine to help with the low end torque, the engineering studies that provided the tuned length for the runners having been done by Chrysler Corp in the 50s, now we have variable length tuned runners on a lot of engines both domestic and foreign. Many of the FWD imports and domestic require removal of the plenum to perform some services on the rear head.
Your problem is all you want to do is bitch and not really listen to anyone who might have been able to help you, wow a whopping 16 posts, you really must have done a lot of asking for help!
As for the intake on the Windsor block truck engines vs the Mustang (also the Crown Victoria, Grand Marquis and Town Car) you obviously have never seen the latter or you would not make that statement. Ford decided in mid 1985 to use that long runner intake on the truck engine to help with the low end torque, the engineering studies that provided the tuned length for the runners having been done by Chrysler Corp in the 50s, now we have variable length tuned runners on a lot of engines both domestic and foreign. Many of the FWD imports and domestic require removal of the plenum to perform some services on the rear head.
Your problem is all you want to do is bitch and not really listen to anyone who might have been able to help you, wow a whopping 16 posts, you really must have done a lot of asking for help!
#37
My point about the 8 PIP signals was why use the signals for the ignition and then not for the fuel injection side.
There are many sites showing how to convert from EFI to SEFI for a reason.
So why would I want to spend thousands of dollars trying to revive old outdated technology for a truck used to make dump runs?
#38
Ian, Mercedes used a batch fire system with the Bosch D-Jetronic units, the Bosch CIS (Continuous Injection System) was a ganged injector similar to the Rochester Ram Jet that Chevy used, all injectors spray constantly, volume changed with load and rpm. FWIW, the D-Jetronic basis was a Bendix system from 1957 that never caught on (Plymouth had it as an option).
Not only does the Ford EFI use all 8 signals, it actually uses two patterns, a leading edge trigger for ignition and EFI and a pulse width trigger that is primarily used on SEFI to correctly sequence the injectors. The #1 blade is narrower than the other 7 which is why you do not want to move the plug wires around on them if the distributor is installed out of time.
As for outdated technology, what is a carburetor, show me one vehicle newer than the early 90s with a carburetor on it as built, you can't!
Not only does the Ford EFI use all 8 signals, it actually uses two patterns, a leading edge trigger for ignition and EFI and a pulse width trigger that is primarily used on SEFI to correctly sequence the injectors. The #1 blade is narrower than the other 7 which is why you do not want to move the plug wires around on them if the distributor is installed out of time.
As for outdated technology, what is a carburetor, show me one vehicle newer than the early 90s with a carburetor on it as built, you can't!
#39
Two or three ford forums netted lots of redundant advice, but did nothing in the long run. When a local Ford technician of 30+ years tells me that it is most likely in the harness and would cost approx. $1K to repair myself or I could take it to the local shop and it would cost between $2-3K for a truck worth less than $1K, you do the math. Still, I did not throw in the towel and disconnected all devices on the TFI side and made my own connections. Still nothing. As I said, 150-160psi across the board, perfectly timed spark at the plug, gas or ether added at the throttle body, and nada. I've never seen anything like it and neither had the Ford technician. And all grounds were cleaned prior to any work. About the only thing we came away with was that it was on the TFI side and after going through all components with no luck decided to go back a generation to a much simpler time. I'd have preferred to stay with EFI but the rail didn't fit with the new distributor. My reasoning for switching to a carb was that if I was crazy enough to spend $2-3K for EFI, then why not convert to something designed in this millennium? I chose the more appropriate $300 fix for a $1K truck. For the most part I'm just teasing the insanely faithful Ford enthusiasts. Particularly the ones that can't say or spell one hundred. Later, as I'm heading to the dump in my sweet running F150.
#40
Then all of your mechanics are absolutely terrible. $1k of your own money and time could completely replace the entire under-hood wiring harness and, every electrical component and every single sensor and actuator on the engine. The TFI system on these trucks has 6 wires, and is about as simple as you can get. In fact, the TFI system is completely self contained, and you could make your own standalone TFI harness with about 30 minutes worth of work.
If they couldn't figure it out, it's because they don't know what they're doing.
If they couldn't figure it out, it's because they don't know what they're doing.
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