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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:
Really? I'll tell you what, why not take a late model 302 and bolt it to, say, a 1962 Ford Falcon.
It's really pretty easy and straight forward.
My Ford has two or three wiring diagrams for the same truck. TFI on the firewall, TFI on the distributor, etc., etc.
The same truck will not have different TFI locations. Certain engines moved to the fender and certain years, but you're not going to have one '91 F-150 5.0 with a distributor mounted module, and another '91 F-150 5.0 with a fender mounted one. That is simply not true.
You even need to pop the inner fender out in order to change the ECU, or as Ford had to call it, the PCM.
...and that takes what, an extra 5-10 minutes at most? I have to remove engine mounts and jack up the engine if I want to change the sparkplugs on a 3.8L Buick. I need to remove the distributor and upper intake manifold if I want to service the injectors on a 350 Vortec V8. Changing the starter on a Lexus LS400 requires complete removal of the engine upper and lower intake manifold.
I have spent $500 trying to fix the EFI/TFI system and in my estimation would need a new wiring harness for approx. $1000.
There's hardly even $500 worth of total components to the EEC-IV EFI system. The engine/EFI harness is separate from the main truck harness, and there are only 38 wires total going to the computer, 5 of which are power and ground. You could completely tear apart the engine harness and replace every wire to the computer in about 3 hours if you wanted.
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.
Crazy vacuum controlled side of things? There are 3 vacuum valves on the engine - the air diverter solenoid, the air bypass solenoid and the EGR valve. It's seriously about as simple as you could get.
Originally Posted by RPetty_43
Regarding EFI, perhaps you could tell me why Ford decided to send 8 PIP signals to the ECU, yet fire off 4 injectors at a time
The computer also controls ignition timing per cylinder, so it needs to read a PIP tooth for every cylinder event to know when to fire the spark.
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.
No one here attributes batch fire to poor fuel economy. The poor fuel economy is due to the old low compression V8s. SEFI only offers improved idle quality and emissions. Your statement about "other companies doing it for decades" is false, too. Almost every single EFI system in the 80s (when Ford's system made its debut) were batch fired. GM even had some port injection systems that fired all 8 injectors at the same time.
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.
It's called batch fire port injection, and it offers greatly improved fuel distribution, cold-starting, idle quality and far better emissions control compared to TBI. Hence why almost everyone in the industry, including Toyota, GM, Honda and Chrysler had batch-fire systems. TBI setups were reserved only for the cheapest engine options. SEFI didn't start taking over until the late 90s, as emissions controls became more stringent.
Very well said Ian. My Turbo Chrysler engine is bank fired, 1-2 and 3-4, staring in 1990 they went SEFI, but still SD control (special 2 bar MAP sensor).
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.
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!
...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!
Bu-bu-but he's gotten hunnerd' year old engines running on less...
That's the best you guys can come up with? 1990 model year vintages? Really? I was talking about foreign vehicles.
Did you actually read my post? I said Lexus, which is Toyota, which is foreign, used batch fire all the way into the late 90s. Mercedes EFI was batch fire until 1995. BMW and Mercedes used mechanical fuel injection in the 80s for crying out loud.
My point about the 8 PIP signals was why use the signals for the ignition and then not for the fuel injection side.
The fuel injection side does use all 8 pip signals. Each bank is fired 4 times per engine cycle.
There are many sites showing how to convert from EFI to SEFI for a reason.
The reason why people convert to SEFI in older Ford systems, is that Ford SEFI systems use a MAF sensor. People convert to get the MAF, the SEFI is just icing on the cake.
So why would I want to spend thousands of dollars trying to revive old outdated technology for a truck used to make dump runs?
Once again with that baseless thousands of dollars. These EFI systems only have 5 major components that really affect how they run, and none of them are particularly expensive.
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!
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.
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.
