84 coupeD 4.1

[witchdoctorjim]

I just bought an 84 Coupe Deville with a solid (and UGLY) body, a sluggish engine, no heat, and a funky smell. My assumption was that the engine's life is limited and I plan to put something new in it, but not before squeezing every bit of performance out of it first (and at a rock bottom price). After that my focus will be the body, interior, and radio.
My engine feels like it's flooding itself with gas and nearly puttering out when starting from a stop. It was completely overhauled at 75000 and is now around 120000, and has spent most of the last 10 years in a KY hay field. Any ideas on what needs to take place first?

[4.9 Guy]

I'd say a rebuild is in order, or drop in a 350 with a 700r4 trans.

[pompeypaul]

i got a gutless 4.1 fwd deville too lol

[steelybill]

My '85 FWD Fleetwood is no performance car either, but has more zip than my 4.3 V6 Chevy pickup We are talking about 249 cubic inches here, so I wouldn't expect too much zip from it.

[carnut]

Having no history of services performed, i would suspect fuel filter and/ or plugged cat converter. You need to verify timing is at at least 10 degrees btdc preferrably 12 degrees, for normal performance. To verify timing, disconnect the green connector behind the distributor, then check the base timing. Must be between 10 and 12 degrees, reconnect green connector, engine off.
They rarely flood but can be running too lean which can feel the same. Also check for fuel pressure to be in the normal range. With the engine running, remove the air cleaner lid. Look down and you should see 2 distinct sprays of fuel from both injectors. I've seen the adaptor under the aircleaner pinch this injector harness which can short out one of the two injectors.

[steelybill]

Shorting the injector wires may also damage the ECM. Good thing to watch for when installing the air cleaner.
There is a tee in the fuel line going to the throttle body, for checking fuel pressure with a gauge. You would need to adapt a fitting/hose to it and remove the valve core in it for a simple pressure test. 9 to about 12 PSI in all engine RPM ranges is normal.
Any old gas in the tank?? It could have a lot of gunk in it. The fuel filter is usually under the driver-side, toward the rear.

[pompeypaul]

living in the uk not many fwd caddys about and know seems to have a clue about them..........mine starts first turn of the key,timing is ok.........but is sluggish definetly not on 8 clyinders ,plugs and leads/cap ok must be coil? breaking down........... stalls on stopping or slowing down to stop ......... any help tips etc gratefully needed its a lovely car seems a shame to send it to the scrap yard

[MrDobin]

Ya I have the same 4.1 front wheel in my seville. Its decent since its a lighter car than a broughman or fleetwood. But curious when I swap engines is a transmission needed?. Keep hearing that the 4100 requires a different trani when you take it out. Duno

[carnut]

A coil would be a guess at best. You need to verify CAT CONVERTER not restricted first, then do a fuel pressure test and report back. This car could start with as little as 8 LB pressure but be sluggish because its below spec.

[steelybill]

YUP!!

[BRICKS]

having similar problems. im workin on changing the fuel pump. hopefully it does the trick.

[steelybill]

You should get a pressure figure before changing the pump. If it's in the tank it's a lot of work.

[ehall]

His 84 is RWD 4.1 not the FWD all us suckers have

Anyhoos, there are not a whole lot of performance add-ons available for these engines so you are stuck with ricer modifications like hi-flow cat and muffler, oversized igntion parts, etc. Advancing the timing makes a huge difference especially if the rest of the work has been done already. My '85 will hold you against the seat on acceleration and surprises the people who mock the cars

With RWD you should just drop in a 350 though

[steelybill]

I had a RWD '85. My wife had an accident in it...total. I believe it had a 2004R trans in it. That sound right? Only had it 7 weeks, so not much time for knowing much about it. I'm aware that some 2004Rs had dual bolt patterns, Chevy and BOP/Cad. The tank issue is the same though with a RWD as far as I know.

[BRICKS]

Fuel pressure was fine but had a hole in the line. After replacing pressure was 0. Not a big hassle dropping the tank on a car lift.

car starts with no fuel pressure but tries to stall out. Also, has a few vaccum leaks that Im working on.