Hi Guys,
I was in the middle of a "tune up" on my 87 GT and ran into a snag. I dropped the engine in order to do the repairs and tune up just because it was easier to access everything with the engine out of the car. While I have the engine out, I wanted to replace the fuel injectors with some extras ones I had lying around. I wanted to do this because the extras that I have were pulled from an engine with significantly less mileage on it then the one I am currently working on. When I compared the two types of injectors, I was shocked to find that they look completely different and had different numbers. I thought they were both stock injectors since they were both pulled from the same type of engine (2.8L V6/both from 87GT's) Please see pictures of both the injectors.





The injector on the left (#5235210) in the one that I pulled and am wanting to replace. From doing some research, I've found that this is the correct injector for the stock 2.8L Fiero GT Engine.

The injector on the right (#5235136) is one from the extra set that I had. These injectors were pulled from an 87GT 2.8L V6 as well, with less than 50K on it.

My question is are these injectors interchangeable? Would I be better off swapping them or leaving the old ones in and not swapping them.....thanks

https://www.fiero.nl/forum/A...020825-2-021425.html

There were 2 kinds of injectors in the 2.8....I don't think you should mix them, but perhaps someone has done it. They rarely go bad and usually just need a good cleaning.

Keep Multecs with Multecs, and Bosch with Bosch. Measure the resistance on each to see if they're close and in the proper range (IIRC 12ish ohms) and use a 9V battery across the terminals for a split second to see if they make a clicking sound.

quote Originally posted by RWDPLZ: Keep Multecs with Multecs, and Bosch with Bosch. Measure the resistance on each to see if they're close and in the proper range (IIRC 12ish ohms) and use a 9V battery across the terminals for a split second to see if they make a clicking sound.

I currently do not have the means to test the resistance...however, i did use a 9V battery to test for a clicking sound....I tested both sets and only 3 of 6 from each set made a clicking sound. Does this mean i definitely have to replace 3 with new? I made a run up to the parts store and new ones are around $70 ea. I sure don't want to replace them if i can help it.

They don't click because they are stuck. There are many cleaning services that will be cheaper than new injectors. Here are two.

http://www.cruzinperformance.com/fuelinj.html

http://www.injector.com/injector_service.html

[This message has been edited by Gall757 (edited 06-09-2013).]

With the battery hooked up you can smack them with a piece of wood to unstick them. Crude but effective. You would want to run some cleaner through to make sure they stay unstuck.

Of course the best way is to pay for a cleaning and flow test from one of the above links. I used Cruzin performance years ago although they could not get 2 of my injectors to work.

Here are ones I've used. Left to right, 15lbs stock (1986), 17lbs Camaro (1995), 24lbs Accel "racing injector"

[This message has been edited by Hudini (edited 06-09-2013).]

I have a set of 6 from a 3.1 that look like your one on the right, they have a number like: A D273 17103007 they have about 60,000 miles on them. If they will work for you just pay me shipping ($6.00) and they are yours. Just clean them up a little. Resistance through the coil is 12.9 Ohms. Larry

PS they look like the 17lb Camero in the middle above

[This message has been edited by trotterlg (edited 06-09-2013).]

The one on the left with the little cap on the tip is the only style I've ever seen come from a 2.8. You can get your cleaned and match flowed for a very reasonable price, or you can get newly rebuilt ones for under $150 per set of 6 from Fuel Injector Connection. http://fuelinjectorconnection.com/shop/ Not far from you, so should have about 2 days shipping each way. They're over in the Metro Atlanta area.

Multec style injectors often give the Fiero ECM problems with proper operation, so you'd be best rebuilding yours or getting replacement pintle style injectors.

Both Injectors will fit but depending on what you have there performance could vary. . The one on the right look like an aftermarket replacement while the one on the left looks original but DIRTY. You can spray carb cleaner in the fuel block before starting to clean the injectors a bit and it may be enough. I would use the best ones and see what happens. If they are rated the same flow rate of 15 lbs you should be close.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

ok so here is an update....i decided to go with the stock injector since is seems, based on my research, that some people have had idle issues using the other other type. I'm hoping to borrow a meter from someone at work tomorrow to test the resistance but here is what i've done thus far. I have two injectors that will not "click" when hooked to a 9V battery. I cleaned them by hooking them up directly to 12V and shooting brake cleaner through them with air pressure (followed a youtube "how to" video) ...I did this in hopes of getting the two non clicking injectors to free up.....when hooked to 12v, they all click and seem to have a good spray pattern....after cleaning them, i tested them all with the 9v battery and still have two not clicking. i'm trying to spend as little as i can at this point so i guess my question at this point is, since they work with hooked to 12v is there any reason that they wouldn't function when installed back into the car. Do the injectors only receive 9v when installed in the engine? thank you guys for all the responses so far.

Edit to add:
Also, I collected the sprayed brake cleaner into a jar so i could soo how dirty the injectors were after cleaning. I was suprised to find there was very little settlement in the bottom of the jar when i was done.

[This message has been edited by labbe001 (edited 06-10-2013).]

bumpity bump.....

The 9v battery is just a nice simple way of checking the injectors. They actually get 12v direct from the fuse box INJ1 and INJ2 fuses. The ECM simply makes the ground to close the circuit. You should check the ohms though. We use high impedance injectors which typically run 12-14 ohms (scale is like 10-16). You just want them all to be similar, not exactly the same.

[This message has been edited by Hudini (edited 06-11-2013).]

On the subject of multec idling:
I can say that I have run into this problem. I inherited multecs with my car and it had a hunting idle when warm. I got refurbs and they too were multecs, and the problem remained. The problem finally seems to have been solved, as of one week ago. The fix consisted entirely of changing how the injectors are calibrated in the ECM.
So I'm now convinced that this issue is real. It's muddied by the fact that there's lots of other things that can also cause hunting, but this is one of them. Also, not all multecs are the same - some are surely less compatible than others.

Absolutely don't mix different injectors in the same car. The ECM can't handle them being different, it has to assume they all flow exactly the same under all conditions. That already doesn't happen in the real world, but it really becomes impossible if they aren't even the same part.

What ECM parameter did you change?

I had a hunting idle I fixed by adjusting the fuel pump voltage vs injector pulsewidth table (7730 ECM and code59). Others have had the hunting idle with the 3.4L swap and Fiero ECM.

quote Originally posted by Hudini: What ECM parameter did you change? I had a hunting idle I fixed by adjusting the fuel pump voltage vs injector pulsewidth table (7730 ECM and code59). Others have had the hunting idle with the 3.4L swap and Fiero ECM.

I changed the voltage offsets, the base constant, and the AE tables, but the key for the hunting idle on my car was the "Low Pulse Width Injector Offset vs BPW" table.
I decided to post about it here:
https://www.fiero.nl/forum/Forum2/HTML/128975.html

[This message has been edited by armos (edited 06-18-2013).]