Author Topic: Fuel injection for 8.2L motor  (Read 3635 times)

Offline dinhnguyen57

  • Posts: 323
  • CLC Number: 31841
  • Name: DNguyen
Fuel injection for 8.2L motor
« on: September 01, 2018, 11:17:21 AM »
Has anyone tried installing fuel injection onto the Cadillac 8.2L motor?  Holley Sniper EFI ($1200) would be an option.  A single plane intake manifold seems to be a requirement.  Cadillac High Performance has one for ($620).  This product does not have mounting for AC.  To be able to mount AC, you would need the March Performance bracket/pulley system ($2500).  Is this all worth it?  Is there a cheaper alternative?

https://www.holley.com/products/fuel_systems/fuel_injection/sniper_efi/sniper_4bbl_tbi_master_kits_with_fuel_system/parts/550-516K

https://cadillachighperformance.com/collections/intakes/products/chp-af05-500-cid-single-plane-aluminum-intake-manifold

https://marchperformance.com/cadillac/cadillac-425-472-500.html
1941 Series 62 coupe
1959 Eldorado Seville
1970 Deville convertible
2007 Mercedes S550
2009 STS
2018 Chrysler Pacifica

Re: Fuel injection for 8.2L motor
« Reply #1 on: September 01, 2018, 11:30:25 AM »
If you are interested in a complete and working factory FI system including manifold, injectors, throttle body, fuel rails, sensors, wiring harness, throttle body, distributor and control unit PM me.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline Scot Minesinger

  • Posts: 6004
Re: Fuel injection for 8.2L motor
« Reply #2 on: September 01, 2018, 02:24:50 PM »
dinhnguyen57,

Cadillac offered fuel injection on the 500 engine in 1975 (maybe 1976) and it was computer controlled.  Fuel injection was also offered in years following on the 425 engine 1977-79.  Fuel injection became standard by Cadillac starting in 1981 I think in the 368 V-8-6-4. 

It may be easier to go with the factory set up as everything will fit and it will require the least amount of work to install it.  Also, value of the car will be better maintained or improved with a factory FI set up that works well.

For power and stop light go, these Caddys do well, but of course a FI 1969 Camero which ways 2,000lbs less will have an advantage.

Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Offline bcroe

  • Posts: 3893
Fuel injection for 8.2L motor
« Reply #3 on: September 02, 2018, 01:42:59 PM »
The 75-79 factory EFI port injection has the advantage that all your
accessories will fit.  But as the last of the analog EFI designs, it lacks
any of the long list of features added with digital systems about 80-81. 
Many people, including GMC motorhome people, have adapted a newer
programable digital ECU to the 76 manifold/injector setup.   Not a
small bolt on project at all.  Bruce Roe

Offline Carl Fielding

  • Posts: 529
  • Name: Carl Fielding
Re: Fuel injection for 8.2L motor
« Reply #4 on: September 02, 2018, 05:45:32 PM »
Was the cam profile different for the factory F.I. cars, and if so, what are the implications for a converted car ?   -  Carl

Offline bcroe

  • Posts: 3893
Fuel injection for 8.2L motor
« Reply #5 on: September 02, 2018, 08:31:27 PM »
Quote from: Carl Fielding
Was the cam profile different for the factory F.I. cars, and if so, what are the implications for a converted car ?   -  Carl 

According to my parts book, all 76-79 500s and 425s used the same
cam, part 1486583.  Bruce Roe

Offline TJ Hopland

  • Posts: 10183
Re: Fuel injection for 8.2L motor
« Reply #6 on: September 02, 2018, 10:19:27 PM »
I'm on my 3rd summer running a FiTech Go4 600 on my 73 Eldo.   The FiTech is pretty much the same thing as the Holley Sniper.   FiTech was out first in the $1000 market and I got mine about the time Holley started slowly shipping Snipers.   If I was to do it again I would consider the Sniper.   Both systems seem to have their issues so it would be a tough choice. 

Before the FiTech I was running a more home brew kit sort of a thing based on a older Holley analog TBI and a Megasquirt ECU.  I ran that for at least 5 years.   Overall it ran pretty good but there were a few glitches that I blamed on that system that I was tired of chasing.   Turns out it wasn't the systems fault, I had the same issues with the Fitech.

I'm running a 75 or 76 intake.  I machined out the front to back divider because at that time I was planning on using a square bore throttle body that had dual bolt pattern so I hoped to mount it without any sort of adapter or spacer.   With the Holley and FiTech you would have to modify the throttle arm to clear the intake plus they are just square bolt pattern so you kinda have to use a spacer anyway.  Spacer/adapter isn't a problem even in an Eldo as long as you stay with a fairly short air cleaner.    Lots of guys on the EFI forums running dual planes.  Some even switched to a single and didn't report any differences.  MTS has an universal AC bracket that works with any intake.  I know for sure it works with a Sanden compressor which is what I am running but I think it also works with the R4.   The magic part is you have to weld or drill and bolt a little L bracket to the main bracket at the height it needs to be for your specific intake.           

For fuel I'm running a RobbMc Power Surge.  FiTech makes a similar unit I think called the G surge.   Stay away from the Fuel Command Center.   Basically what these are are small fuel tanks you feed with the stock mechanical pump.   They contain a OE style electric pump that boosts you up to the 50ish psi the current systems take.

For ignition I'm running a gutted HEI from an 81.  IF I had that to do again I would go with a regular HEI with a lockout kit.  The 80/81 DEFI HEI uses a odd bolt on cap rather than the typical easy to find spring clamp version.   Either way you don't need the internal module, you are connecting direct to the pickup coil.   FiTech can then direct drive a coil or ignition box.   Holley you have to buy some sort of coil driver module or use an ignition box.       
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Offline dinhnguyen57

  • Posts: 323
  • CLC Number: 31841
  • Name: DNguyen
Re: Fuel injection for 8.2L motor
« Reply #7 on: September 03, 2018, 01:32:07 AM »
Thank you for all the information.

The car that I am trying to install EFI is a 41 custom Cadillac coupe.  This is Bob Hoffman's car.  It has a NOS Eldorado 8.2L motor with a 400-transmission.  I actually had already bought the Holley Sniper master kit and had a Cadillac mechanic installed the kit.  It would idle cold OK but when it gets warmer, it would shut off.  You can turn the engine on again, of course.  It would run on the streets like "the gas tank was empty," despite a full gas tank.  I am finding out from the majority of the EFI experts, particularly the ones who are knowledgeable on the Holley system, say I need a single plane intake manifold.  (I have the stock dual plane manifold).  It has been suggested that I "port" the dual plane or cut out the divider entirely, or get spacers.  I am a bit of a novice mechanic and I am afraid to experiment, especially when time=money.  I've ordered the single plane manifold from Cadillac High Performance, as it may be more of a guarantee to work out. 

I'll keep everyone posted on the outcome.

I thought about installing the factory EFI system from the 1975+ Cadillac models, but I the Holley has already installed.  Although, I would like to keep the who project as "Cadillac" as possible, I decided to go with new modern technology and new electronics and wiring over old technology, old seals, old rubbers, and old electronics, as I am not good at trouble shooting and fixing things as many of the members are on this forum.
1941 Series 62 coupe
1959 Eldorado Seville
1970 Deville convertible
2007 Mercedes S550
2009 STS
2018 Chrysler Pacifica

Offline bcroe

  • Posts: 3893
Fuel injection for 8.2L motor
« Reply #8 on: September 03, 2018, 10:00:22 AM »
I have not figured out the advantage of EFI on these old engines.  Yes
it will adjust better to extreme temp or altitude situations, but most of
these cars never go there.  Sure engine management is essential with
high tech stuff like turbos and variable camshafts.  The manufacturers
needed it to meet emissions and to squeeze out the best MPG possible,
not really bested until multiple feedback loops were added. 

One thing to note is the big difference between MAP and MAF systems. 
The Manifold Absolute Pressure system is just estimating the weight of
air going into the engine, so mixture errors are possible. 

The  Manifold Absolute Flow, preferred by manufactures, directly measures
the weight of air going into the engine, making the fuel-air mixture quite
accurate.  It requires careful ducting, making installation more complex. 
I tried a FAST version a couple decades ago, and was surprised at how well
it handled the 20 below zero F weather in which I was then driving to work. 

An OEM MAF system, lifted off perhaps a manufactures big block, may
perform very well with the minimum amount of adjusting.  Not so any MAP. 
In any case more instrumentation is needed for EFI work, I start with a fuel
pressure gauge and a WB Oxygen Sensor. 

Bruce Roe
« Last Edit: September 03, 2018, 02:34:18 PM by bcroe »

Offline Eric DeVirgilis CLC# 8621

  • Posts: 7036
  • Name: Eric DeVirgilis
Re: Fuel injection for 8.2L motor
« Reply #9 on: September 03, 2018, 12:04:56 PM »
If the reason for asking is worries about vapor lock experienced in the '41, my advice is not to proceed and leave the 4 bbl carburetor setup just as it is on the '76.

A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

Offline TJ Hopland

  • Posts: 10183
Re: Fuel injection for 8.2L motor
« Reply #10 on: September 03, 2018, 12:19:44 PM »
I don't know a tactful way to put this.....  You need a new mechanic and better forums for your EFI info.   Single plane vs dual is a possible fine tuning issue NOT a makes it quit when it warms up issue.  You need to run far far away from anyone that is telling you switching to a single plane intake will solve this problem.   Only way it could is if in the process of swapping intakes they accidentally happen to solve the real issue.   

By far the worst and most screwed up systems I have either seen/worked on myself or read about on forums have been ones that were 'professionally' installed.   The inexperienced DIY people that decided to do it themselves usually come out alright because they do the research.    Its the people that pick the wrong professional that seem to have the most issues.   I'm sure there are good shops out there but of course you don't tend to hear as much about those as the bad ones. 

I have minimal hands on experience with the current Holley stuff but at this point it sounds like you are dealing with some pretty basic issues which are not brand specific.  Lots of questions need to be answered here to start narrowing down where the issue may be, here are the first few:

What is the fuel pump setup?    My exposure to this stuff that is where about 75% of the issues come from.

What is the ignition system?   Is the computer running it or is it stand alone?   If its stand alone was it running fine with the carb and hasn't been touched during the EFI install? 

Has this engine and ignition system been run in this car with a carb?

What is the condition and general size and layout of the electrical part of the system?   How big is the alternator and battery?   Where is the efi power hooked?   Where is the ignition hooked?  Was that the same way it was with the carb?    Is the ignition switch original or new?  If newish is it all DIY or from one of the big names like Painless?     
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Offline Bob Hoffmann CLC#96

  • Posts: 5102
Re: Fuel injection for 8.2L motor
« Reply #11 on: September 03, 2018, 01:59:56 PM »
TJ,
 Very well put & to the point.
Dinh,
 Sorry you're having problems. What ever you do, do NOT let the mechanic pull the hood to remove the intake. It took LOTS of effort to achieve that perfect alignment.
 Bob
1968 Eldorado slick top ,white/red interior
2015 Holden Ute HSV Maloo red/black interior.
             
Too much fun is more than you can have.

Offline dinhnguyen57

  • Posts: 323
  • CLC Number: 31841
  • Name: DNguyen
Re: Fuel injection for 8.2L motor
« Reply #12 on: September 03, 2018, 02:52:25 PM »
Thank you for all the good advice.  Much appreciated.  I will go back to the carburetor set up that has been working fine.  Anyone wants a like-new Holley EFI?  (Just kidding.)
1941 Series 62 coupe
1959 Eldorado Seville
1970 Deville convertible
2007 Mercedes S550
2009 STS
2018 Chrysler Pacifica

Offline bcroe

  • Posts: 3893
Fuel injection for 8.2L motor
« Reply #13 on: September 03, 2018, 03:02:39 PM »
Quote from: dinhnguyen57
     The car that I am trying to install EFI is a 41 custom Cadillac coupe.  This is Bob Hoffman's car.  It has a NOS Eldorado 8.2L motor with a 400-transmission.  I actually had already bought the Holley Sniper master kit and had a Cadillac mechanic installed the kit.  It would idle cold OK but when it gets warmer, it would shut off.  You can turn the engine on again, of course.  It would run on the streets like "the gas tank was empty," despite a full gas tank. 

Without knowing much about yours, it sounds like the insufficient fuel
problem I have seen on the 70s system.  With a failing MAP, these cars
may run on cold enrichment till is goes away, then quit. 

Instead of guessing and wasting resources, I suggest again get a gauge
on it that will tell what the air/fuel ratio is.  If it is low the problem could
be many things, but the first I try to check/eliminate is the fuel pressure. 
Here are the affordable gauges I am recommending/using on some cars.

WBOX from Evil Bay. It should have a moving indicator, as any digital display
will be only a blur of segments on a fast transition (just when you need it).
401576516054
APSX V2 Anti-Glare D2 Digital Wideband O2 AFR Gauge & Sensor Kit
AFR ratios in properly working fuel injection should be more or less as follows: 12.5 for WOT
13 for accelerating
14.5 for cruising
15.5 for lean cruising
13.5 for idle (it is desirable to set slighty enriched mixture for smooth operation)

In addition I have added an electric fuel pressure gauge. These pressures are
for the 70s Cad peak and hold system, other ranges are available for
what you have.  For the 70s the pressure should rise (approaching 39psi) when
you push it hard, not drop. Forget the old mechanical gauges that quit and may
even cause a fire.
eBay item number: 271992161854
Pressure Transducer Gauge 60 psi, 2-1/16"/52mm, analog voltage input,
LED light $35
eBay item number: 261508176203
Pressure transducer or sender, 60 psi, stainless steel, for oil,fuel,air,water $22

If you don't want to spend anything on the instrumentation, my none
too subtle advice is get out of DIY fuel injection.  Bruce Roe

Offline Scot Minesinger

  • Posts: 6004
Re: Fuel injection for 8.2L motor
« Reply #14 on: September 03, 2018, 04:30:33 PM »
Second the no need to pull a hood to install the intake - that is just nuts!  I'm must have read over that before, sorry.

I'm 5'-9", 165lbs, age 57 and have no problem managing the weight of the intake manifold on my own by hand.  It might weigh 40lbs tops. 

If a mechanic suggest that the hood be removed to me for such a modification, I would run like heck away.  Many of the posts we read and try to help with our the result of unfamiliar mechanics guessing and not reading the shop manual and messing things up major.  One mechanic pulled the engine out of 1976 Eldorado, when if he had just removed a valve cover he would see the small clip failure that holds in rocker arm, and for low cost (parts are about $20) it would have been fixed.  Only work with a quality mechanic who will read the shop manual.

BTW, I would just leave it as a 4bbl.  The extra 20 hp rated at the factory for making this mod seems not worth it.  Several have converted their EFI to carb.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Offline TJ Hopland

  • Posts: 10183
Re: Fuel injection for 8.2L motor
« Reply #15 on: September 03, 2018, 04:40:53 PM »
One, perhaps the most critical question I forgot to ask is what does this owner hope to get out of EFI?   Many people do it for the wrong reasons.  Maybe going back to a carb would be a good move in this case. 

If this engine and ignition system was running fine with a carb that is good information to know.  Many people make the mistake of trying to install EFI on an unknown or worse yet a new/ just rebuilt engine.   Way too many extra variables with either one of those scenarios.   Having and engine and ideally ignition that is broke in and tested good with a carb is the ideal starting point for an EFI install.   Another mistake many people make including me was installing it to solve a problem.   EFI may be able to mask problems better than a carb but won't solve them.    If you have a bad engine build or a tired engine its still going to be bad or tired when you put EFI on it. 

Answering those questions I asked earlier would give me and others that may know about these systems a better idea what we are working with and from there can maybe narrow things down a bit where we should be looking.   Like I said earlier and Bruce was eluding to getting a clean steady fuel supply at the proper pressure is a critical factor and where many installs go wrong.   I should also ask about the regular and or return system you are using, that is another place a lot of people go wrong.

If you are lucky enough to be doing this on a popular car they make properly baffled tanks with the internal pumps.  People that go that route almost never have fuel issues.   If they don't make an EFI tank for your car then you are starting at a disadvantage.   Inline pumps are the most common and IF installed properly work OK.  Not great, just OK.  If they are improperly installed which seems to be the case about 90% of the time they are nothing but problems.     

General info: 

Wideband O2 is part of all the modern systems.  Having a 2nd opinion isn't a bad idea but at this point (engine just quitting) isn't going to tell you anything you don't already know or can't tell by ear.   I had it happen to me early on and read about it all the time on the forums where the O2 reading just causes you problems.   Misfires will screw up the readings.   What I learned is to just tune it by ear and feel to get the engine to idle and rev in the driveway.   If the engine runs smooth its going to be in the ballpark O2 wise.   Once it runs fairly smooth you can then start looking at the readings to dial it in or in the case of the new self tuning systems like the one we are talking about here let it start learning.   

Oddly a fuel pressure sensor isn't part of or even an option for most of the EFI systems but then again it wasn't part of OE stuff till more recently either.   Being a critical component to be correct you would think it would be more common but its not.   As far as I know none of the current systems use a popit injector like the 90's Vortec truck motors did.   Those were interesting because they needed a minimum pressure to open at all.  One psi to low and you got no fuel.   Most systems if the pressure drops you just don't get the amount of fuel you were expecting.     

One issue a lot of the systems have especially these newer 'cheap' ones is quality of components.   Till the FiTech came out around 3 years ago for $1000 a typical similar spec EFI system was in the $2500-3500 range.  One of the things I think they did to get the cost down was to do some value shopping on some of the components.   The $3500 systems used big name genuine sensors like Bosch and Delphi.   When they started trying to make the kits cheaper one way they did it was to start supplying no name parts.   You are likely getting a $20 o2 sensor instead of a $90 one.   I'm not saying you need to just start throwing parts at it but its something you should be looking at in the data.   Just like any EFI engine you have to look at what the various sensors are reading and make sure they are reasonable numbers and consistent.   

StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Offline Bob Hoffmann CLC#96

  • Posts: 5102
Re: Fuel injection for 8.2L motor
« Reply #16 on: September 03, 2018, 06:23:09 PM »
Guys,
 This is my old car. I installed a NOS 70 Eldo motor,T400 trans & 70 posi rear end. I advised Dinh on not putting the FI unit on the car. It's his car now & he decided to do it anyway. I spent thousands on making that hood fit the best in the country. I just want to avoid a bad situation. Scot, I guarantee that you could not lift the intake from that car. It's NOT the kind of car you work on . So... Dinh told me he was going back to the carburetor. Good move!! His pain is my pain as there's lots of me in that car. I want him to enjoy it.
Bob
1968 Eldorado slick top ,white/red interior
2015 Holden Ute HSV Maloo red/black interior.
             
Too much fun is more than you can have.

 

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