[markfothebeast]

1995 Trans Am LT1 V8

I am curious as to what replacement injectors with stock specs are compatible? I read a few posts about Ford or LS1 Bosch injectors working but also read conflicting information. My injectors are leaking and I can only afford what is available at my junkyard. There are no F-bodys currently. If anyone is running different injectors with stock specs with no issues, I would be grateful for a part number.

 

[KW Baraka]

......I read a few posts about Ford or LS1 Bosch injectors working.......

Yes. They do.

BTW....I got a set of fully functional 30LB Ford SVO injectors (about 55K miles).

PM me if interested.

KW

 

[markfothebeast]

Do you have the part number? And would 30lbs rated for a Ford run at 24lbs on the LT1?

 

[steveo]

Do you have the part number? And would 30lbs rated for a Ford run at 24lbs on the LT1?

they wont. you'd have to re-tune.

 

[markfothebeast]

I am going to pick up a bunch of injectors since I can get them for $5 a set. I am going to try every 24lbs injector I can get my hands on and see which works the best. If anyone has a 24lbs injector part number please post it so I can cross reference it.

 

[markfothebeast]

Thanks for the info, Steveo.

I have no access to an ALDL connector at this time (or knowledge of PCM flashing) so I would be unable to use the 30lbs injectors.

However, I am going to attempt to run other EVx style Bosch 24LBS injectors. I am interested in trying the thinner style with the flat tip 4-hole. I have swapped that style into several different vehicles that were running the older 2-hole or single pintle valve type with good results.

 

[steveo]

other 24lb injectors will work ok, but still better with a re-tune (different injectors have different timing). you may notice idle quality and a slight decrease in fuel economy or something.

 

[BALLSS]

OP

you can send your injectors out for rebuild for IIRC $12 per. I used Cruzin Performance

Rich did a few sets for me

 

[markfothebeast]

I cleaned the injectors. They really needed it. The filters were terribly dirty inside. The plastic spacers crumbed apart. The spray patterns were clearly flawed from debris. I had a couple sticking open because the plunger wouldn't close. The OEM injectors themselves on the LT1 just aren't that great. The spray pattern between these and the newer Bosches is night and day. For now I'll run these but in the future I'm going to test a newer set.

 

[markfothebeast]

Here's how bad one of the injectors is leaking. Nearly entirely stuck open.

https://youtu.be/mFWekBDcte8

 

[markfothebeast]

I'll flush it reversed a few times and if that don't work I'll need to replace it. Don't have the time.

 

[markfothebeast]

I managed to reverse flush it a couple times and it no longer leaks or drips.

 

[markfothebeast]

other 24lb injectors will work ok, but still better with a re-tune (different injectors have different timing). you may notice idle quality and a slight decrease in fuel economy or something.

Doesn't the PCM control the injector pulse as in timing? Or is the timing of the injector basically the limitation of the hardware such as the time it takes for the solenoid to open and close the valve?

 

[steveo]

Doesn't the PCM control the injector pulse as in timing? Or is the timing of the injector basically the limitation of the hardware such as the time it takes for the solenoid to open and close the valve?

different injector designs take a different amount of time to open from being completely closed.

the ecm indirectly controls when the injector opens, to get accurate timing, it needs to take into account how long after applying power the injector is actually going to pop open...

these are referred to as injector offsets, and they vary per voltage applied (that's why you usually see microseconds vs volts in an offset table)

more advanced injection systems (with different injectors and peak and hold drivers) actually shove a ton of current into the injector to force it open, then reduce it before the coil burns up, this ensures faster and more predictable opening time.

an injector that opens more quickly than intended will deliver fuel too early (resulting in pooling), and too much of it

of course this isn't a super precise thing, +/- a few percent in fuel or a bit of offset in timing isn't really noticeable.

 

[markfothebeast]

I got ya. I remember some older vehicles that ran low resistance injectors that demanded high current.

I gave up on my injectors. I happened to find one that doesn't function at all and leaks. I found a set of injectors from an LS1. From what I've read, these would work without any changes to the PCM?

 

[steveo]

as mentioned earlier, anything 24lb (or more specifically anything that's 24lb at 43.5psi) will run well, but will run better once you tune injector offsets properly.

you need to know what part number they are, there are a few different LS1 stock injectors.

then, since stock ls1 rail pressure is more like 58psi (i think, might wanna double check that), LT1 injector flow should be 0.866025 times ls1 injector flow (since sqrt(43.5/58) = 0.866025)

so if they're about 26.5lb LS1 injectors you should be fine

to complicate matters, depending on their design, injectors designed for higher pressure sometimes open more quickly or slowly than intended due to the extra pressure at the back of the pintle or whatever, and since you're running them at ~15-20psi less than normal... not sure if that's an issue in this case or not.

 

[markfothebeast]

The ones I've found I believe are 28# at that 58ish psi. I read somewhere that it comes down to the 23 or 24ish mark and doesn't require a PCM tune. But that's just from a random read on a forum. The other 24lbs injectors I saw online are EV6 ftom a 1996 to 1998 Ford 3.0L Duratec that are sold for use on an LT1.

 

[markfothebeast]

The junkyard is loaded with Fords including Mustangs so if I could find Ford Bosch injectors that work I can easily swap to those. I have a difficult time finding ANY LS or LT1 in any yard. After working on Fords and seeing the junkyard that should be a good hint to new potential Ford owners out there (hehe).

 

[cocobolo95]

That was an interesting testing setup you were using in your video. If I may ask, what did you use on the end of the copper tubing to hold the injector in place?

 

[markfothebeast]

1/2" copper straight pipe. The inner diameter is tight so it required a bit of sanding. Nothing holding injector in. Plan to make something when my permanent machine is complete.

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