Injector Advice Needed

[Burnsmacdonald]

I am getting ready to swap in a stroker six in place of the current 4 cylinder I am currently running in my 98 Jeep TJ and need some advice on injectors.
Here are some specs on the stroker build:
- 1998 Jeep TJ 4.0L block over-bored by 30 thou
- 4.2L crank
- 4.0L conn rods
- Comp Cam Extreme 4x4 camshaft
- Keith Black forged alloy performance pistons with the pin height offset to compensate for the 4.0L rods
- block decked with a 50 thou quench
- 4.0L head, ported, polished and blueprinted
- performance grind on the valves and seats
- Harland Sharp roller rockers
- heavy duty valve springs
- spring seats milled to accommodate springs and rockers
- BBK 62mm throttle body
- stock 4.0L intake manifold port-matched to intake ports on head and throttle body

The existing injectors are 21lb stock injectors and I am running the stock in-tank fuel pump and stock 6cyl ECU

Should I be ok with the existing injectors. I hate to buy 24lb injectors unless I need to as my budget is getting thin and they are not cheap. Alternatively, if you guys agree that they might work, I can try them and run a wideband analyzer on them to see where I stand, once we fire it up. However, if I find that they don't work, that will mean my trail rig will be another week sitting in the shop while I send away for them.

Thoughts from you guys that have been down this road?

[Cheromaniac]

Your stock injectors flow 23.3lb/hr at 49psi but they won't be big enough for your planned stroker build.
A set of Accel 150624 injectors will flow 25.5lb/hr at 49psi and should suit your needs, but you'll also need a set of six EV6 connector to EV1 injector adapters (cheap).

[Burnsmacdonald]

Ordered the injectors you recommended (Ford Racing M14464A8) and ev6 adapters from Summit racing this morning. Should have them in about a week.
What cam are you running in yours and do you use the stock ECU?

[Burnsmacdonald]

Your stock injectors flow 23.3lb/hr at 49psi but they won't be big enough for your planned stroker build.
A set of Accel 150624 injectors will flow 25.5lb/hr at 49psi and should suit your needs, but you'll also need a set of six EV6 connector to EV1 injector adapters (cheap).

Just noticed that you recommended Accel injectors. Someone else had recommended the ford injectors. Do you know if they will work?

[Burnsmacdonald]

Sorry bad

Confused part numbers here. I actually did order the Accel injectors you recommended (#150624)
It was the adapters that were Ford Racing

Time for another coffee probably

[Cheromaniac]

What cam are you running in yours and do you use the stock ECU?

Stock cam, stock ECU, Ford Racing 24lb injectors (39psi fuel system), MAP adjuster at 5.15v.
Goes like a raped ape. Jeep has done 254k miles with almost 80k miles on stroker.

[Burnsmacdonald]

Really useful info that will help
Good to know that a stroker can be so reliable.
Thanks!

[bgmiller]

I have a 97 TJ with about 200K. I had a freeze plug rust out and I know that the rest are about to fail as well. Also the oil pressure drops to Zero when rpm drops below 800. No to mention with 35s this is a dog on the interstate trying to maintain 75mph for long distances.

I am getting my AX15 rebuilt right now(syncros are bad and I have been dealing with them for about 3 years already) and a new clutch installed. I plan on stroking the engine before the end of the year and I would like to start gathering parts now. Since I don't have a garage I will have a local garage do the build and the install the stroker.

Do you know what your compression ration is?
Do you have a part number for the pistons you are running?
Is the engine installed and running, if so what grade fuel are you using?

[Burnsmacdonald]

Not ignoring you - I am trying to find the part numbers. Obviously my filing system needs work.

The compression ratio should be about 9.3:1, so it will run on pump (hi-test) gas.

The engine is not yet installed. That will occur in 3 weeks. It is sitting there finished and primed with break-in oil. Just a scheduling issue.

One other trick thing is the addition of a baffle to the oil pan so I don't lose oil pressure on steep declines. Curious to see how well it works.

If you are going to go to a larger throttle-body make sure you port-match the intake manifold otherwise your larger throttle-body will be wasted.

[Burnsmacdonald]

[/url]Found it!
Keith Black Icon performance pistons. Part no. IC944 I believe these are them: http://www.summitracing.com/int/parts/u ... overview/
Harland Sharp roller rockers. Part no. S4096 http://www.summitracing.com/int/parts/csp-s4096
Note that you may have to chamfer the rockers slightly to clear the valve cover. You also will want to adjust the springs and may need to machine the spring seats on the head.

Cheers

Burns

[rwkhaussupply]

FYI, I see it says that you have a 98 TJ. And then I read someone telling you you need adapters for the elect plugs in to the accel Injectors.

98 has EV1 elect connectors.
Accel high inp 24 ~ 40lb injectors have a EV1 connector on them.

[Burnsmacdonald]

Yes, all true.

I received both the adapters and the injectors. It doesn't appear I will need the adapters, but luckily they weren't expensive.

[Burnsmacdonald]

[quote Keith Black Icon performance pistons. Part no. IC944 [/quote]

I believe the auto machinist who did the short block work milled valve reliefs into them. I can try to check for you as the engine is now assembled and I don't want to pull the head.

[Burnsmacdonald]

Accel 24lb injectors worked great. Mixture was a bit rich at first but has evened out and is good now.
Picked up a new fuel rail. Amazingly, the injector clips are ridiculously expensive, but I replaced them anyway, as everything else is new and the old ones were rusty.
Very good throttle response and smooth idle.

Didn't need the EV adapters as the Accel injectors matched the OE harness.

Engine finished. Just breaking it in and then ready to rock n' roll!

Burns

[SilverXJ]

You didn't really need the clips