GTP Injectors

[arthansen]

I just finished upgrading to 36# GTP injectors. The swap was a pain. I had to shorten the fuel rail supports and cut the Delphi electrical connectors off and solder on Bosch style connectors. However, once done, it ended up being a very nice installation. More importantly, it solved the two problems I was having.

First, I was maxing out my stock injectors. This happened with or wothout the nitrous. When they maxed out the power would stop climbing and the Air Fuel Ratio would go lean (the HP on the dyno peaked and leveled off at 5300 rpms, the exact point the injectors went static). Hopefully, now that the injectors do not max out, there is some more power above 5300 rpms.

Second, I was seeing a strange effect on the injectors when the nitrous was engaged. The injectors would reduce the pulse width, causing the engine to go VERY lean (16.0). With the bigger injectors, the problem has gone away.

I spent $50 on the used GTP injectors and $40 on the connectors. However, if I had to do it again, I would spend the $300 and get Delphi injectors so it would have been plug and play. I would not recomend this mod though I am very happy with the results (the modifications are only needed on 2000+ f-bodies).

This Wednesday it is back to the track and hopefully a new best. We will see.

[T-Punk]

good to here it went well, i am going to have to do the same thing eventually and i will probalby cheap out like you did. with your programmer you will probably be able to get a lot out of those injectors. Hope it improves your times.

[AllTheGoodNamesAreGone]

Hey Art, Before I put myself though the hell you just did.

Can you take a picture of the stock connectors? and the GTP injectors you used?

its me missing2 from HPT.

I got the gtp injectors as well.. but from what I understand they are the "newer style" ones..

dunno.. i am trying to figure out of they will jsut plug in..

[arthansen]

Look at the GTP injectors. If the two electrical connectors are pins, they should hook right up. If they are wide and flat, welcome to hell.

I will get some pics and post them. You do realize that if you got some that are plug and play I will have to drive up there and kill you.

[AllTheGoodNamesAreGone]

what do you mean by pins??

rofl.. its kinda hard to describe I know.. i have been trying to think of a way to do it..

ok.. here we go.. i will get a picture..

searching google..
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http://www.12v.org/maintenance/repai.../finjector.gif

they more or less look like that.. I hope they are right.. rofl.. becuase I plan on shipping them out and having them tested, cleaned, and flow matched..

[98Camaro3.8]

If it helps, here's the pics from the service manual.

1998 Injector: http://www.leadingedgesim.com/mkapro...98Injector.gif

2000 Injector: http://www.leadingedgesim.com/mkapro...00Injector.gif

[AllTheGoodNamesAreGone]

thanks mat.. but the gtp injectors i have dont really look like either of those..

they are pretty much dead on that image i posted..

[98Camaro3.8]

I think the 1998 style goes with the one you posted. The one you posted is the injector itself, while that 1998 one is the harness-side.

As you can see, the 2000 connector uses pins like he said, versus the flat prongs in the one you posted.

[WickEdSix9838]

My 98 has the two flat pins if that will help anyone.

[arthansen]

The GTP injectors I used look like the picture ATGNAG posted. They have two knife like, flat connectors in line with each other.

The stock injectors look like the second drawing 98C3.8 posted. They have two pins that are like an ice pick, thin and long.

I will get pics tonight but go pull the plug off one of your injectors and see if it plugs into the GTP injectors. It sounds like it will not fit. The oter problem is the length, the GTP injectors are 4 mm shorter, so the rail suports need to be shortened 4 mm. Hope this helps.

[foff667]

glad to hear you got your issues worked out.

[arthansen]

Here is the stock injector.

http://home.cfl.rr.com/akaeh/StockInj.jpg

Notice the two thin pins.

Here is the GTP injector.

http://home.cfl.rr.com/akaeh/GTPInj.jpg

Notice the two wide flat pins.

Just an update. The new injectors are great. I played with the flow rates a little and got my Long Term Fuel Trims (LTFT) between -4 and 0 (right where they need to be). The only area that I still need to work on is the LTFT at idle. I guess since the injectors have a less fine adjustment, the idle is effected more. It idles fine but the LTFT are 15-20 possitive (adding lots of fuel) I will have to adjust the VE table to bring those in line but I do not plan on idling much at the track. ;)

Again, this is not a job for someone who does not know what they are doing. I almost torched my car because of a simple mistake on how the clips hold the injector to the rail. I put them in one way and the electrical connectors were very tight. Turnes out the electrical connector was pushing on the clip, causing the o-ring not to seat properly. After about a quart of fuel poured all over the back of the engine, I shut it off. I stood and pointed a fire extinguisher at the car for 5 minutes. I found the problem and turned the clips around. I have about 150 miles on the car and no more problems. Just remember, pay attention to how you take it apart and put it back the same way (take notes and pictures). Thanks for everyones support.

[AllTheGoodNamesAreGone]

DOH..

Looks like I will be shoping for new injectors..

I dunno.. i am torn on the issue..

one side says "do the conversion on the harness" so it can take any standard ls1/lt1 stly injector.. incase i need bigger ones in the future, which I probably will..

the other says thats too much work, just get new ones..

dunno.. tough choice..

[98Camaro3.8]

Originally posted by AllTheGoodNamesAreGone:
Looks like I will be shoping for new injectors..

If you decide to sell those GTP injectors you've got now, let me know...I'll take them off your hands. ;)

[AllTheGoodNamesAreGone]

go to ed morad.. moradparts.com or something like that..

he sells them cheep..

I dunno.. I am pretty sure I am gunna do the conversion.. the multitech style connectors on the later cars are crap.. no one really makes much ofr them that will be a direct fit..

so.. i will probably just end up rewireing like art.. :(