upgrade for 96 injectors

I have a set of LT1 chevy injectors. Are the 96 injectors in the jeep as big of a piece of crap as the older jeep injectors. These are a near perfect match fot the 23# in the Jeep right now, and they have 6 ports for fuel spray. Any thoughts would be great. MPG increase?

maybe2fast said:

I have a set of LT1 chevy injectors. Are the 96 injectors in the jeep as big of a piece of crap as the older jeep injectors. These are a near perfect match for the 23# in the Jeep right now, and they have 6 ports for fuel spray. Any thoughts would be great. MPG increase?

Click to expand...

No, they're not. The problem injectors were the "RENIX" units (1987-1990 4.0L,) because they were a metal body crimped onto a plastic top. The later (all-plastic body) units were still made in two pieces, but the halves are ultrasonically welded together after assembly.

The RENIX units would leak because the crimp finally vibrates loose. Oops.

If you want to see about getting a slight improvement in efficiency, I've heard good reports from the field about the Ford units - the ones with a four-hole nozzle. Apparently, this atomises the fuel rather more finely, helping with combustion efficiency (liquid gasoline doesn't burn - gasoline vapours burn quite handily. Atomising the fuel is an intermediate step toward vapourising it.

You will probably not note an increase in power or efficiency with the Chevvy units - I believe they are the same construction as the Chrysler units you're now using. I could be wrong, however - I've not seen tests or detailed drawings to compare the units...

the Chevy units have 6 ports. They both have the same resistance. and at the 39psi from the 43.5 psi they flow just about the same. 23ish.

Also the chevy units are a different make than the chysler injectors.

maybe2fast said:

the Chevy units have 6 ports. They both have the same resistance. and at the 39psi from the 43.5 psi they flow just about the same. 23ish.

Also the chevy units are a different make than the chysler injectors.

Click to expand...

"Same construction," not "same make." They're both Bosch-style injectors.

Also, I didn't know about the six ports in the nozzle. Source, please? I'd like to look into that a little deeper...

the injectors I have are from an extra set of 1993-97 LT1 SBC. I am using a set on my 400hp Trans Am (stock injectors).

The injectors are a 260cc (24.7#) at 43.5psi. At 39psi these injectors get very close to 23#.

they are the same construction (same body shape)

These LT1 injectors have 6 nozzles in them and I thought for atomization purposes these would be better than the chrysler ones.

How many nozzles are in the chysler injectors? I haven't removed them yet.

those '96 injectors are a single pintle.

single! as in one nozzle...

the chevy injectors are going in asap!

1:6 atomization

Let us know how you get on. Have you been taking fuel economy readings for a while so you can tell if they are any better or not?

yeah it sucks, I will report back asap.

!!!!! instant difference !!!!!

As stated the Stock injectors are single nozzle and the chevy injectors have 6 nozzles. I went for a test drive and went around a corner like normal and the rear tire broke loose...maybe I am looking for differences but it feels smoother and accelerates smoother and the throttle response I know for sure is better. Definitly worth the hour i spent on it.

I wish I had a dyno to see the difference. I am on E so I will fill up and report back the trip mileage.


If you have a 96 definitly worth looking on Ebay for a set of 94-97 LT1 injectors...24.7#. With the lower psi of the jeep the injectors are a near perfect match

What other mods have you to the intake/exhaust etc?

no other mods at this time, cone filter is on its way. and a performance muffler of some sort in the future.

Only the injectors, otherwise stock, motor wise.

I believe the 96's fuel pressure is 49psi, thus those LT1 injectors are probably flowing more than 24.7#.

all the research I did said they are 23# at 39psi

A 96 runs at 49 psi. Only the ones that have a fuel pressure regulator on the fuel rail are at 39 psi. So if you dont have a vacuum line running to the front of the fuel line, you are at 49 psi. My 95 has the regulator on the fuel rail which is the last year that had them. Changed along with the switch to OBDII.

Here is the information from Dino's site about it.
Injectors

Some of those specs that are hard to find in any workshop manual.

The following is a list of the injectors used on the 4.0L since 1987 along with their rated static flow:

Model Year, ...Part #, ......Colour, .....Fuel Pressure, ...Static Flow,
'87-'90, ........53003956, ...Black, ........39psi, .................18.6lb/hr
'91-'93, ........33007127, ...Brown, .......39psi, .................21.0lb/hr
'94-'95, ........53030343, ...Tan, ...........39psi, .................21.0lb/hr
'96-'99, ........53030778, ...Grey, .........49psi, .................23.2lb/hr
'00-'01, ........04854181, ...Blue tip, .....49psi, .................22.5lb/hr

The injector flow rate varies as the square root of the pressure drop across the injector. The stock '91-'95 4.0 injectors are rated at 22lb/hr @ 43psi fuel pressure, so at 39psi they flow ( sq. rt.(39/43) x 22.0 = 21.0 ).
For stock/modified 4.0 engines or stroker build-ups the following injectors can be installed. The flow rates are:

Ford Motorsport 19.0lb/hr @ 39psi (Part no. FMS-M9593-C302)
Ford Motorsport 24.0lb/hr @ 39psi (Part no. FMS-M9593-A302)
Ford Motorsport 30.0lb/hr @ 39psi (Part no. FMS-M9593-B302)
Chevy LT1 24.0lb/hr @ 43.5psi (Part no. 17124248)
Chevy LT4 28.0lb/hr @ 43.5psi (Part no. 17124251)
'98 Chevy LS1 25.2lb/hr @ 58.0psi (Part no. 12533952)
'99-'00 Chevy LS1 26.2lb/hr @ 58.0psi (Part no. 12456154)
'01-'02 Chevy LS1/LS6 28.6lb/hr @ 58.0psi (Part no. 12482704)
Accel 19.2lb/hr @ 44.1psi (ACC-150119)
Accel 21.1lb/hr @ 44.1psi (ACC-150121)
Accel 24.4lb/hr @ 44.1psi (ACC-150124)
Accel 25.6lb/hr @ 44.1psi (ACC-150126)
Accel 29.4lb/hr @ 44.1psi (ACC-150130)

The '95 Jeep 5.2 ZJ/Dodge 5.9 injectors (Part no. 53030262) are rated to flow 24.6lb/hr at 39psi.

The selection of injector size will depend on the estimated horsepower output, brake specific fuel consumption BSFC (assume 0.5), no. of cylinders, and the injector duty cycle (assume 80% or 0.8). The formula is:

Injector size (lb/hr) = (horsepower x 0.5)/(no.of cylinders x 0.8)

The ECU reading the O2 sensor will still keep it as close to 14.7:1 air fuel ratio. You might just be running a bit richer when warming up as the ECU does not read the O2 sensor then.

the truck runs great, idles like its not running (it didn't before) has good power (pretty sure its better).

its a great upgrade. I am very happy with the drivability results. I will calculate mileage as soon as I am in need of more fuel.

Let us know as that is what counts to me. What were you getting before typically?

Can we get a part number
Year of vehicle if it wasn't mentioned
Maybe a pic of the injector

Thanks.

I know that any 94,95,96 Chevy Caprice/Impy LT1 will have those injectors. Lookout in the boneyards!

almost all LT1s (Trans AMs, Camaros, Impys, Caprice, Caddys) some of the very first years had a tad bit smaller flowing injectors.

No need for pics, they look darn near the same. I will however try for a installed pic and a nozzle pic.

I was getting about average MPG, nothing great, nothing horrible, but below 20mpg

Idle smoothed out alot