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I pulled the engine from a 77 Seville with fuel injection and I’m having a few issues I hope someone can help me with. It is an Oldsmobile engine and I’m converting it from FI to carbureted.
I’ve sourced a fuel pump and Chinese distributor from Amazon after being unable to find an OEM unit. I found an intake manifold on Marketplace.
The issues are:
There is no timing marks tab. Since the Seville had fuel injection and some kind of sensor on the distributor, was the tab not required? At any rate, I need one. I’ve scoured the internet and can’t find one. Any help here?
Rather than going with a Chinese replacement carburetor, I’m trying to find a rebuildable Q-jet. In the event I can’t, what would be the best substitute? I understand that I can use a squarebore carb on the spreadbore manifold.
I cleaned the oil pan out and was pleasantly surprised. The only thing in it was a little sludge in the sump. The odometer in the donor car read 82k. So far, it looks like that may be actual. While waiting for the distributor, I spun the oil pump with a drill. The oil pressure was 35-40 at probably 12-1500 rpm. I’m thinking that’s good.
Im hoping someone can help me with these two issues. I will be glad to share any information I can in the future.
While I generally wouldn't recommend a Chinesium distributor, it's the same thing you can buy at an auto parts store. FWIW, you can't run a spreadbore carburetor on a squarebore intake manifold without an adapter. I suggest buying an aftermarket carburetor from Summit Racing or Jegs if you can't find a Quadrajet to rebuild.
I was wondering what to do with it. I don’t know where you live but I’m in Republic, MO, zip code 65738 and this setup weighs a ton! Shipping will be killer. What are your thoughts?
The Seville EFI system has several variations. The intakes were made in both cast iron and aluminum. The computer control is analog, not digital, and does not even use an O2 sensor for feedback. Most of the parts and sensors are no longer available new, and even finding correct injectors can be a challenge. The distributor is unique to the EFI setup and has a box cast into the housing below the main body where a separate RPM sensor is located. Of course, the biggest problem is that that intake actually flows worse than a stock 2bbl intake. I actually have most of one of these more as a collectable than to actually use it.
The Seville EFI system has several variations. The intakes were made in both cast iron and aluminum. The computer control is analog, not digital, and does not even use an O2 sensor for feedback. Most of the parts and sensors are no longer available new, and even finding correct injectors can be a challenge. The distributor is unique to the EFI setup and has a box cast into the housing below the main body where a separate RPM sensor is located. Of course, the biggest problem is that that intake actually flows worse than a stock 2bbl intake. I actually have most of one of these more as a collectable than to actually use it.
did you flow the intake yourself or did you read that somewhere?
did you flow the intake yourself or did you read that somewhere?
That is based on what I have read. No, I do not have first-hand info. The bores for the throttle body are smaller than the ones on the GM TBI intakes. The actual intake body is a flat open plenum, similar to the crappy Offy intakes. Here are pictures of the iron and aluminum versions.
That is based on what I have read. No, I do not have first-hand info. The bores for the throttle body are smaller than the ones on the GM TBI intakes. The actual intake body is a flat open plenum, similar to the crappy Offy intakes. Here are pictures of the iron and aluminum versions.
For comparison, here is the Offy.
you shouldn’t believe what you read on the interwebs..you’re spreading bs. Stick to what you know, part numbers and the manuals
ive flowed both the iron and aluminum FI intakes, they both flow well over 200cfm. that’s because they are wide open and have no runners to speak of and draw from both sides of the throttle body…
I’ll post pics and flow numbers for each . Why post a pic of an offy? It’s got nothing to do with the Olds FI intake,, you are spreading bs you’ve read online.
I know this is an old thread. But as a new proud owner of a 1980 Cadillac Seville with Olds 350 EFI. Looking for all the info I can find. I came across this post and youtube video. Also Joe, in 1980 went digital including Map sensor and O2 sensor.Its a low mileage 36,000 in great shape. But most of the parts are original on the car. Replacing most of the 45 old parts. I have found most of the parts nos. But only two new injectors so far. Even found a few ECM Computer for this very engine.. This engine is so much stronger and easier to work on than all the other 1985 Seville HT4.1 I have owned. My new cross-country go to car. Just floats over road.
I know this is an old thread. But as a new proud owner of a 1980 Cadillac Seville with Olds 350 EFI. Looking for all the info I can find. I came across this post and youtube video. Also Joe, in 1980 went digital including Map sensor and O2 sensor.Its a low mileage 36,000 in great shape. But most of the parts are original on the car. Replacing most of the 45 old parts. I have found most of the parts nos. But only two new injectors so far. Even found a few ECM Computer for this very engine.. This engine is so much stronger and easier to work on than all the other 1985 Seville HT4.1 I have owned. My new cross-country go to car. Just floats over road.
Very cool! I was not aware of the switch to digital for 1980. I know the Eldos that year were labeled DFI (Digital Fuel Injection). Of course, that means a lot of the unobtanium EFI parts are one-year-only.
There are rebuilds and rebuilding serves out there. BWD are NOS. The listing for 1976-1979 is incorrect. These are for 1980 , the part numbers are correct for 1980.
Another guy was able to find new AC Delco ones. 6 out of 8 were bad. I am sure they were import. Why I search the internet looking for USA made NOS.
Last edited by HighwayStar 442; Aug 28, 2025 at 05:36 AM.
Why I search the internet looking for USA made NOS.
^^^THIS^^^
It be a good idea to search the nation and find another Eldorado/Toronado you can salvage for parts. I bought a core IDI diesel engine for my 86 Ford truck and I have plenty of rebuild able injectors as spares (16+).
It be a good idea to search the nation and find another Eldorado/Toronado you can salvage for parts. I bought a core IDI diesel engine for my 86 Ford truck and I have plenty of rebuild able injectors as spares (16+).
Only 36,000 miles. It's in great shape. Only things like the brakes, brake hoses, shocks etc are all 45 years old. I am replacing it all. Door gaskets, hoses, belts, plugs. I need this car up and running for road trip to see family back east. So, I just went to RA to get most thing fast. I have a lot of Seville parts from the other one I owned. And even 350 SBO parts.
Cool to hear the last of the Oldsmobile EFI was more modern fuel injection. So these EFI intakes flow over 200 cfm, what do the stock carb, Street Dominator, Performer, RPM and Victor flow for the SBO? What about velocity vs flow?
Cool to hear the last of the Oldsmobile EFI was more modern fuel injection. So these EFI intakes flow over 200 cfm, what do the stock carb, Street Dominator, Performer, RPM and Victor flow for the SBO? What about velocity vs flow?
This is all about soft ride. For my old bones on long trips. It just needs to be dependable. SBO 180 HP with 260 lb-ft. Faster than the 85 Sevilles with HT4.1 125 HP and future boat anchor. I have Highwaystar for bute power and the TeslaY
Agree, that is why I have a V6 AWD Challenger, is it a Hellcat, no and isn't supposed to be. The extra inch ground clearance and AWD make towing and successfully launching and taking my boat out possible getting mid 20's MPG, up to 40 MPG Imperial just cruising. My point is how do other intakes stack up compared to these EFI intakes? For 180HP, they flow plenty but where do they become a major bottle neck?
See the youtube I posted. Its wide open!! I see your point.
The injectors are small. Even the holes for them in the manifold are small. I would think a larger flowing injector, you would need to drill the holes bigger somehow. To install them. There are lots of this year intake around! Most just pull them off and go with normal intake and carb. Go get one.
Cadillac did not want their owner to have to pump the gas pedal a few times to start engine. One just turn the key and it starts. This car is all about comfort!! It has 69 pound of insulation to cut out noise. Even the steering has a damping shock. Have a nos USA Monroe one.
1980 39,344 were built. How many 350 gas is unknown. But it has its own following.
This is my first time for injectors. I never wanted to mess with them. Even Bill T. ask me if I want to go with injectors in my Nascar HP build.
To be honest, I don't even know this car had injectors. Until I open the hood in my garage.
But I just love the floating ride over anything on the road. Potholes, RR tracks, anything. It's like sitting on your couch on a boat floating on the water. Like Joe P said, lots of the unobtanium EFI parts are one-year-only. I have found most of the parts. Two new BWD injectors on the cheap so far. 6 more to go.
It runs ruff, I will get it efi to work. Since I want to do a lot of traveling. I save on gas over the carb. This old dog can still learn. If not, 2711 or 3711 intake and old NOS Quadrajet from HighwayStars old engine. I know how to milk that Quadrajet for good gas mile.
Last edited by HighwayStar 442; Aug 28, 2025 at 06:19 PM.
Yeah, it is too bad the 350 was discontinued or it would have been put on the 307 in 81 and upgraded till the 307 was canceled. Imagine a SEFI 307 with higher compression, roller cam and a long runner torque intake on a Cadillac, H/O and 442. It sure would have beat the terrible 4.1 under powered POS iron head and aluminum block nightmare.
