Fuel Injector Help for 85 - 93 Vettes

[James W.]

I have been working with Jon Banner (Fuel Injection Connection) to get a set of ethanol-resistant fuel injectors that have original appearance and function. Attached are a couple pictures of what I have installed in my 1990 ZR-1. These are 1995 Delphi injectors that have been modified to fit the Z. The part number, of course, is not correct, but everything else is. The car runs perfect.

http://s385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/?action=view&current=IMG_0693.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0703.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0690.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0685.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0687.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0702.jpg

Some of you may not know it, but the early multi-port injectors were wet-coil injectors, which means that the gasoline is in direct contact with the injector coils. The ethanol in newer fuels deteriorates the insulation on the injectors (mine made it to about 12,000 miles) at which time they begin to short out. Initially, the car actually seems to run a bit better, because the injector tends to stay open a bit longer. It first shows up during emissions testing. As the injectors deteriorate they stay open way too long and short completely out, causing them to quit. At this point the inectors put such a draw on the coil packs that they can short out as well, usually after the car has been run a while. Later, the coil just fails completely.

Putting the old-style Multeck injectors that are going to fail again did not make sense to me, although I can now pull, reassemble, start, pull, reassemble, and start in less than 4 hours, as I had a new GM 545 coil crap the bed on me, which was found after the first reassembly. If anyone is interested in these you can either PM me or just go to the FIC site, fuelinjection connection.com. If you call (numbers on the website) ask for Jon and tell him you want the same injectors sold to Jim White. I hope this helps some of you out, and no, there's no kickbacks. It has just taken me several sets of injectors and much pain to get this far.

Jim

[Joe L.]

Re: Fuel Injector Help for 85 - 93 Vettes

I have been working with Jon Banner (Fuel Injection Connection) to get a set of ethanol-resistant fuel injectors that have original appearance and function. Attached are a couple pictures of what I have installed in my 1990 ZR-1. These are 1995 Delphi injectors that have been modified to fit the Z. The part number, of course, is not correct, but everything else is. The car runs perfect.

http://s385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/?action=view&current=IMG_0693.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0703.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0690.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0685.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0687.jpg

http://i385.photobucket.com/albums/oo297/vettn71/Injector%20Replacement/IMG_0702.jpg

Some of you may not know it, but the early multi-port injectors were wet-coil injectors, which means that the gasoline is in direct contact with the injector coils. The ethanol in newer fuels deteriorates the insulation on the injectors (mine made it to about 12,000 miles) at which time they begin to short out. Initially, the car actually seems to run a bit better, because the injector tends to stay open a bit longer. It first shows up during emissions testing. As the injectors deteriorate they stay open way too long and short completely out, causing them to quit. At this point the inectors put such a draw on the coil packs that they can short out as well, usually after the car has been run a while. Later, the coil just fails completely.

Putting the old-style Multeck injectors that are going to fail again did not make sense to me, although I can now pull, reassemble, start, pull, reassemble, and start in less than 4 hours, as I had a new GM 545 coil crap the bed on me, which was found after the first reassembly. If anyone is interested in these you can either PM me or just go to the FIC site, fuelinjection connection.com. If you call (numbers on the website) ask for Jon and tell him you want the same injectors sold to Jim White. I hope this helps some of you out, and no, there's no kickbacks. It has just taken me several sets of injectors and much pain to get this far.

Jim

Jim-----


The strange thing is that GM has specifically approved the use of fuels containing up to 10% ethanol since the mid-80's. So, one would think that the injectors would have been designed to accommodate that recommendation.

As far as the 1992 model year is concerned, the fuel injectors originally used for both ZR1 and LT1 are still available today from GM and Delco under the original part numbers.

For 1990 ZR1, the original injectors were replaced with supercessive part numbers more than 10 years ago.

[James W.]

Re: Fuel Injector Help for 85 - 93 Vettes

Jim-----


The strange thing is that GM has specifically approved the use of fuels containing up to 10% ethanol since the mid-80's. So, one would think that the injectors would have been designed to accommodate that recommendation.

As far as the 1992 model year is concerned, the fuel injectors originally used for both ZR1 and LT1 are still available today from GM and Delco under the original part numbers.

For 1990 ZR1, the original injectors were replaced with supercessive part numbers more than 10 years ago.

Joe,

What you're saying is true. As a matter of fact, my 90 ZR-1 Owner's manual specifically says it can use ethanol up to 10% --- GM lied. This has been a topic of discussion on the ZR1netregistry.com and nearly every owner has had failed injectors due to ethanol in the gas. When GM was approached about this a few years ago their response was that the cars were designed to run on the fuel availble at the time and they were not going to make any adjustments. Interpretation --- we're not selling those any more so we don't really care. If you were to put new GM Multec injectors in a early C4 you'd find they are extremely expensive, not ethanol resistant and will begin to fail in 12,000 to 20,000 miles. Not much of a deal. The part numbers don't reflect a real change either, as GM often goes to a service replacement part that fits several model years after production. There's quite a bit of information in the various ZR-1 forums and C4 forums, as well as websites that deal specifically with the ZR-1, although my understanding is that the injectors were not ZR-1 specific.

ANyways, that's what I did and why I did it. Not saying I'm the sharpest knife in the drawer, just trying to get by.

Jim

[Joe L.]

Re: Fuel Injector Help for 85 - 93 Vettes

Joe,

What you're saying is true. As a matter of fact, my 90 ZR-1 Owner's manual specifically says it can use ethanol up to 10% --- GM lied. This has been a topic of discussion on the ZR1netregistry.com and nearly every owner has had failed injectors due to ethanol in the gas. When GM was approached about this a few years ago their response was that the cars were designed to run on the fuel availble at the time and they were not going to make any adjustments. Interpretation --- we're not selling those any more so we don't really care. If you were to put new GM Multec injectors in a early C4 you'd find they are extremely expensive, not ethanol resistant and will begin to fail in 12,000 to 20,000 miles. Not much of a deal. The part numbers don't reflect a real change either, as GM often goes to a service replacement part that fits several model years after production. There's quite a bit of information in the various ZR-1 forums and C4 forums, as well as websites that deal specifically with the ZR-1, although my understanding is that the injectors were not ZR-1 specific.

ANyways, that's what I did and why I did it. Not saying I'm the sharpest knife in the drawer, just trying to get by.

Jim

Jim----


The 1990 ZR1 fuel injectors were uniquely applicable to 1990 ZR1; they were not used on any other application. The current SERVICE 1990 ZR1 fuel injectors are the same as 1991-92 ZR1 PRODUCTION and SERVICE fuel injectors. They are uniquely applicable to the ZR1 application, also.

The 1993-95 ZR1 fuel injectors are of different part numbers than earlier. However, they are also uniquely applicable to ZR1 applications.

[Walter G.]

Re: Fuel Injector Help for 85 - 93 Vettes

Although not a ZR1, I experienced fuel injector problems due to ethanol with my standard '89 in 1994. I purchased fuel (w/ethanol) in Iowa on my return to MN from Bloomington Gold and several days later my car kept killing and would barely run. I limped it to the dealership and it was concluded that all the injectors were bad to the tune of about $900! Left with no choice at the time, I had them replaced. Several weeks later I got a check from GM for $600 and one from the dealership for $150 as a sort of 'goodwill' gesture. Never had any more issues, as the new injectors were supposedly 'ethanol compatible'. It was nice to see GM stand behind the product-probably would not be the case today...

[James W.]

Re: Fuel Injector Help for 85 - 93 Vettes

Although not a ZR1, I experienced fuel injector problems due to ethanol with my standard '89 in 1994. I purchased fuel (w/ethanol) in Iowa on my return to MN from Bloomington Gold and several days later my car kept killing and would barely run. I limped it to the dealership and it was concluded that all the injectors were bad to the tune of about $900! Left with no choice at the time, I had them replaced. Several weeks later I got a check from GM for $600 and one from the dealership for $150 as a sort of 'goodwill' gesture. Never had any more issues, as the new injectors were supposedly 'ethanol compatible'. It was nice to see GM stand behind the product-probably would not be the case today...

Joe,

I guess I could have stated my position more accurately. I appreciate your knack for putting a fine point on things. Accuracy is important, but I was referring to the big picture here, not individual part numbers. All GM Multec injectors made before 1993 were of a wet coil design that was not ethanol-resistant, regardless of claims made by GM. It doesn't matter whether it was put in a Cadillac, Buick or Corvette, the basic design was the same, even though part numbers differed. As a case in point, the injectors currently in my 90 ZR-1 are for a 1995 Cadillac. The primaries fit right in - no modifications, while the secondaries had to be machined to accept the o-ring seal on the bottom of the injector. My guess is that as ethanol becomes more widely used more issues are going to crop up. Just trying to help my fellow Corvetters.

[Jon S.]

Re: Fuel Injector Help for 85 - 93 Vettes

All GM Multec injectors made before 1993 were of a wet coil design that was not ethanol-resistant, regardless of claims made by GM. It doesn't matter whether it was put in a Cadillac, Buick or Corvette, the basic design was the same, even though part numbers differed.

This is a good point - the problem is not unique to ZR1 injectors at all. I just went through this on my '91 Callaway Twin Turbo. The car started running very rough, and testing revealed that 4 of my 8 injectors were shorted, and a fifth one was borderline. I talked to Jon Banner, but he did not mention any 'near stock' option. Since this car is not something I'll have NCRS judged, I went with the Bosch Design 3 injectors from Jon (which work GREAT, by the way).

For future reference - do you happen to know if they have done something similar with the L98 injectors? Given the choice, I would have preferred to keep a stock appearing injector.

[James W.]

Re: Fuel Injector Help for 85 - 93 Vettes

This is a good point - the problem is not unique to ZR1 injectors at all. I just went through this on my '91 Callaway Twin Turbo. The car started running very rough, and testing revealed that 4 of my 8 injectors were shorted, and a fifth one was borderline. I talked to Jon Banner, but he did not mention any 'near stock' option. Since this car is not something I'll have NCRS judged, I went with the Bosch Design 3 injectors from Jon (which work GREAT, by the way).

For future reference - do you happen to know if they have done something similar with the L98 injectors? Given the choice, I would have preferred to keep a stock appearing injector.

Jon,

I used myself as the guinea pig, as Jon never gave it much thought. We discussed what I needed for NCRS judging and he tried a couple options, the first of which did not work out well. It could have been a bit of trash in my fuel rail that got lodged in the Standard-brand injectors he made up for me the first go-round and caused an injector leak. However, he investigated other types of GM injectors that would have the correct appearance and function and this is what he came up with. Now that he understands what NCRSers need, I think you'll find he can make up suitable injectors for most any car. Like I said, mine are 95 Caddys. BTW, he not only ate the cost of the original injectors, but didn't charge me for express shipping, machine work or any type of return fee, even though the fault could have been mine.

Jim

[Joe L.]

Re: Fuel Injector Help for 85 - 93 Vettes

Joe,

I guess I could have stated my position more accurately. I appreciate your knack for putting a fine point on things. Accuracy is important, but I was referring to the big picture here, not individual part numbers. All GM Multec injectors made before 1993 were of a wet coil design that was not ethanol-resistant, regardless of claims made by GM. It doesn't matter whether it was put in a Cadillac, Buick or Corvette, the basic design was the same, even though part numbers differed. As a case in point, the injectors currently in my 90 ZR-1 are for a 1995 Cadillac. The primaries fit right in - no modifications, while the secondaries had to be machined to accept the o-ring seal on the bottom of the injector. My guess is that as ethanol becomes more widely used more issues are going to crop up. Just trying to help my fellow Corvetters.

James----


I suppose I could have been clearer, too, with respect to what I was getting at about part numbers. Here's the deal: although 1990 LT5 fuel injectors were replaced by the 91-92, the 91-92 injectors sold today by GM are the same as those used in PRODUCTION for 91-92. That is indicated by the fact that the part numbers have not changed and is what I was getting at with respect to part numbers. While there may have been minor changes to the injectors via revisions to the specs for the particular part number, if there had been significant changes (e.g. a change away from the wet coil design), I'm sure the part number would have changed.

The same is true for LT1. The part number sold today to SERVICE 92-93 Corvettes is the same as that used in PRODUCTION for 1992-93; the part number used to SERVICE 94-96 is also the same as that used in PRODUCTION for those years.

If these injectors were highly failure-prone due to ethanol fuel blends or for other reasons, I would think that the injectors (and, of course, their part numbers) would have changed by now. For example, the 1990-92 LT5 injectors might have been replaced by the ones used for 93-96 or the 92-93 LT1 injectors might have been replaced by the ones used for 94-96. Of course, there may be other reasons why the later injectors for both the LT5 and LT1 would not be compatible with earlier engines. Nevertheless, if the earlier design were highly failure-prone, I would expect, at the least, the improved technology built into later design injectors would be incorporated into new SERVICE injectors (and, of course, those new-design SERVICE injectors would have new part numbers).

However, the fact that the part numbers did not change indicates that no significant changes were made to the injectors right up to the present day. It's possible, of course, that GM just chose to ignore the problem with highly failure-prone injectors and kept selling the same pieces regardless. It seems rather unlikely to me, though.

[Joe L.]

Re: Fuel Injector Help for 85 - 93 Vettes

One other thing: something that I have been extremely careful about ever since I drove away in my new 1992 LT1 in the fall of 1991 is to use ONLY Top Tier fuel. I have NEVER used any fuel other than Top Tier. Gasoline base stocks are usually pretty much the same among brands; gasoline ADDITIVES are NOT THE SAME among brands.

I don't think that Top Tier is much of an issue for older cars with carbureted engines. However, for fuel injected engines, I think its VERY important.

[James W.]

Re: Fuel Injector Help for 85 - 93 Vettes

James----


I suppose I could have been clearer, too, with respect to what I was getting at about part numbers. Here's the deal: although 1990 LT5 fuel injectors were replaced by the 91-92, the 91-92 injectors sold today by GM are the same as those used in PRODUCTION for 91-92. That is indicated by the fact that the part numbers have not changed and is what I was getting at with respect to part numbers. While there may have been minor changes to the injectors via revisions to the specs for the particular part number, if there had been significant changes (e.g. a change away from the wet coil design), I'm sure the part number would have changed.

The same is true for LT1. The part number sold today to SERVICE 92-93 Corvettes is the same as that used in PRODUCTION for 1992-93; the part number used to SERVICE 94-96 is also the same as that used in PRODUCTION for those years.

If these injectors were highly failure-prone due to ethanol fuel blends or for other reasons, I would think that the injectors (and, of course, their part numbers) would have changed by now. For example, the 1990-92 LT5 injectors might have been replaced by the ones used for 93-96 or the 92-93 LT1 injectors might have been replaced by the ones used for 94-96. Of course, there may be other reasons why the later injectors for both the LT5 and LT1 would not be compatible with earlier engines. Nevertheless, if the earlier design were highly failure-prone, I would expect, at the least, the improved technology built into later design injectors would be incorporated into new SERVICE injectors (and, of course, those new-design SERVICE injectors would have new part numbers).

However, the fact that the part numbers did not change indicates that no significant changes were made to the injectors right up to the present day. It's possible, of course, that GM just chose to ignore the problem with highly failure-prone injectors and kept selling the same pieces regardless. It seems rather unlikely to me, though.

Joe,

I hear you, brother. In my discussions with numerous ZR-1 owners (pre1993) it seems that GM did just dump us. The part design did not change, as the design did not change, so you are again absolutely correct in your statement about the design/part number. This was not a ZR-1 issue, as evidenced by the other responses and I think we will see more failures due to the ethanol issue. I would have preferred to think GM would make changes to a dfective design, but money is money. Since ethanol was not in widespread use until recently, it makes since that the issue would remain hidden. I think there was another post on the effects of ethanol on mechanical fuel assemblies, or maybe it was an article in the Restorer.

Jim