Has anyone had experience with swapping stock a 351W 5.8 EFI system with the Holley Sniper EFI system? Wondering about compatibility and fittings.

For reference - I have been lurking on these threads since I bought the truck. I have close to zero experience with anything engine related. I purchased a 94 F-150 OBS 4x4 extended cab short bed over a year ago and found stalling issues almost immediately. The truck ran great until it got to operating temp and then when stopping to turn or if not keeping the RPMs up, the truck stalls out. Technicians have looked at it extensively for the last few months and have not been able to pinpoint the issue. Checked TPS, IAC, EEC, etc to no avail. One guy recommended the Holley Sniper EFI system which would essentially be hitting the 'reset button' and give me the ability to tune the system initially and allow the unit to learn and make adjustments over time. Was told this would also make the engine more reliable. Interested to hear other experiences from folks who have either swapped stock EFI systems with Holley systems or have any thoughts on other potential solutions. Happy to provide additional information if anyone has thoughts.

 

Its been done. In my opinion it's not even remotely worth the money. You're not gaining anything by removing a perfectly serviceable MultiPoint Port Injection system, and replacing it with a Throttle Body setup.

If you're chasing tunability, you're better off investing in something like a Quarterhorse, Tweecer, or PiMPx.

 

I have dealt with ignition modules dropping out when hot, worth a look. Last summer was the most recent time on the TFI unit.

Ford put FAR more time and money into R&D of the EEC-IV system than Holley did on their kit. Not saying the Holley is bad, but I would be curious if they will still work in 25-30 years. Sounds like the techs gave up, told you to change electronics as they cannot diag it.

 

If your truck has an E4OD automatic transmission that Holley system cannot interface and control it. Even more money to make it work.

 

Pull the existing computer & open it up. I swear this should be defacto first step when when purchasing/receiving/acquiring one of this vintage trucks.

Examine for leaky capacitors, overheated/burned components. Record/photo label. Post calibration number to verify correctness. Start looking for replacement regardless.

If you can't at least master the basics of the stock system & know how to test them, you'll really be behind the 8-Ball & Murphy in the front seat with you if you try & go after-market.

Just sayin... Your results may vary.

 

I converted my 88 to carburetor because after months of frustration I had 2 mechanics and my dad telling me it would be better than dealing with the "junky" stock efi. Knowing what I know now, they were wrong. The real problem was that no one working on the truck actually knew how the Ford EFI system worked much less had to diagnosis and repair it, and the carb was a short cut to get to something they did understand. The advice you have received seems to be in the same vein to me.

Unless the truck has been damaged or hacked up the stock system is reliable. Your best bet is to learn to work on it yourself or sell it for something much newer.

This forum is a great resource if you want to do the work yourself.

 

How did you check each of these components?

Swapping to an aftermarket EFI system, to fix a running issue, may result in a bunch of money spent and still no fix for the problem.

 

Thanks for the input - I will look at those options as well. Trying to learn as much as I can

 

Nice looking truck.
Start up a "help fix my truck" thread. Make your initial post as detailed as possible with everything you know about the truck and the problems it has, include some under hood pics and then stay engaged and try to answer any questions that are asked in a timely manner. Chances are your truck has one or several common problems that affect all of them and it won't take long to start to eliminate possibilities from the list and zoom in on what is ailing your truck.

 

Im gonna chime my two cents in here. Some may not like my answer, but oh well.

Part of the problem is we are dealing with a 30 year old vehicle that is using an obsolete technology. OBD1 and EARLY OBD2 systems are not as user freindly as newer systems, and as such as the technicians that worked on them when new get out of the business, we dont have the "tribal knowledge" base that has worked on them for years to rely on to fix an old obsolete system.

Conditions of the vehicles varies greatly, from nearly showroom condition, to "did this survive the crusher already?". as such, the components are not always in the best of conditons, wiring harnesses age and the insulation breaks down, components fail, engines are at or past their design lifetimes and are still running, but give all manner of faults that may or may not be detectable with modern computerized systems. Components are rarely available "NEW" and reman components are usually not up to snuff as when the system was new. This adds to the owners frustrations

The recommendation of a more modern aftermarket EFI system CAN be valid in certain situations, they are much more tunable and you dont have to go with throttle body systems, they have aftermarket out there that uses port injection the same as we already have installed, making it a bit more "plug and play". Of course there is compatibility issues with all of the sensors, and its not a panacea , but if the original system is so degraded or parts so unobtainable that economic repair of the dated system no longer makes sense, it is a valid alternative. As stated, there are some which will interface with the computer controlled transmissions out there. Thing is these systems are not "cheap", nor are they "foolproof". then again, nothing on these trucks is either cheap, or foolproof anymore.

here is but one example of a port system that would work, vice the throttle body system
Holley EFI 550-604N HP EFI ECU & Harness Kits

 

It is not that I don’t like your answer but I have a different outlook. I haven’t had any problems with my “obsolete” technology. I upgraded the camshaft and heads and also converted to MAF using a Mustang computer. With option to keep the OEM EFI system and use a PimpX ECM/PCM now available I see no reason to either spend that kind of money on an aftermarket sequential EFI system or downgrade to a TBI system.

 

OEM or like OEM is typically the best, and definitely the cheapest. Only real reason I would abandon the factory system wholesale is in the case of a full systems failure such as an underhood fire taking out the wiring harness and other major components, or REALLY going off the reservation with regards to engine mods. Im not a huge fan of "junkyard" replacements for electronics as they can have their own issues that may or may not be seen right off the top. 30 year old parts are usually well past their "best before dates" at this point. Yes many are still giving good service, but lets face facts, these things were NEVER designed to last this long. Some engineers would consider it a fatal flaw that planned obsolescence hasnt killed them all off by now..... Heck, my 95 has over 300k on the clock, looks a bit worse for wear, but is still running and driving relatively reliably, a testament to the durability of most of the components. That said, if the computer went, or rats attacked the wiring, I would bin factory in a heartbeat (especially in the case of a bad ECU) and go with aftermarket stuff (what system exactly would depend on the failure) that still has some semblance of "factory support" over remanned or NOS and hope for the best.

 

Well that's great for you. But the whole thing about this place is options & what a person choses to do.

Personally I do shoestring & cheap salvage parts all day. I've gone to stinger because it's biggest bang for the buck in the eec-IV architecture & gives me as much control as the Holley for a fraction of the cost...

Plus it controls the trans.

Wiring doesn't bother me. There's new donors to my collection of parts everyday & the stock stuff is amazingly resilient.

For a tech newbie, mine & many others advice will continue to be learn the stock operation & fix yourself with our help first.

If he, (or me for that matter) win the lottery, spend the dough on spanking new stuff.

 

Not trying to argue here. The stinger setup looks like a decent piece of kit. If it can use many of the factory components, then it will definitely be cheaper, however still possibly handicapped by the quality of the parts in the system. as we know from other threads, the quality of OEM replacement parts can be very "lacking".... to say the least. Here in AZ the trucks live forever until SOMETHING kills them, either an accident or other damage. Old wiring harnesses do not do well with the heat, the connectors are usually completely roached by the time they get to this age. Since the connectors unfortunately arent readily available to replace old and brittle originals, when the wiring goes belly up, thats needless to say a major issue. Pimpx has the harnesses new, and thats great, but once everything is priced out, they are running not much cheaper than the other alternatives out there. What I am trying to say is that there are other options to "factory" as many have gone. I dont have any skin in the game pushing any one system over any other. I just know that companies such as MSD, Holley and other big "performance" names have decent stuff, mostly used to make a car that never had EFI able to use EFI. Chances are they arent going anywhere anytime soon, save for major legislative changes that make their products no longer marketable (not gonna get into politics here....). As you also state, there are many options available for those with differing budgets, starting with a carb conversion, on up to Lincoln grade aftermarket. Some options are better than others, and when the stock system cries Uncle, its up to the owner how far down the rabbit hole they go to get back on the road

 

In this particular case, I wouldn't recommend spending $2500 on an aftermarket EFI system, as a means of troubleshooting. I agree that there are advantages to these systems (I have one), but I really don't see any justification to install one, if the cause of the idle problem can't be identified first.

My previous question to the OP about "Checked TPS, IAC, EEC, etc to no avail". I'm curious to know how these components were tested.