1989 IROC-Z 5.7L fuel system overhaul
 

I have a 1989 IROC-Z 5.7L that has been sitting in various garages for ~ 10 years for various reasons (deployments, kids, etc...) that I am FINALLY getting into. I have diagnosed that the fuel pump is faulty, and wanted to pursue a fuel system overhaul (tank, fuel pump assembly, lines, regulator, etc.) over the course of the next few months. I've been looking around online and see a number of people recommending the Walbro 255LPH pump, but cannot seem to find a kit for the whole assembly with it. I'm reluctant to go start ordering parts before I have some confidence I am ordering the correct ones for my particular vehicle. My question:

Any part numbers available for fuel pump/lines/kits?
What brand is recommended?

I will follow up with pictures.

-Jason

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Acdelco ep241 is a good pump, if your going through the whole fuel system check out southbay fuel injectors and fuel rail o-ring kit.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

SO- As of now I am looking at:

ACDelco EP241 Fuel pump
AM Autocrats fuel sending unit
14 Gallon gas tank with neck.

Enough to get me working at least right? Any recommendations/alterations?

Still plan on pursuing :
Fuel injectors
Fuel lines (as I see damaged ones, etc.)
Fuel regulator

Thanks!

Jason

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Is there a different fuel tank you would recommend?

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

And- on the sender- I would be open to any brands anybody can recommend. This just seems to be all I can find at the moment.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Here’s a few other options

https://cimg8.ibsrv.net/gimg/www.thi...c5384baa62.png

https://cimg9.ibsrv.net/gimg/www.thi...534630e50e.png

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Rumor has it that the aftermarket tanks fit poorly, and lack the internal baffling of the later TPI tanks. Unless the tank is rusty, I'd stick with the stock tank.

My project car's plates expired in 2009. Aside from some stink, and some flakes, the inside of the tank wasn't too awful bad. I soaked up as much of the old rotten gas possible with paper towels, then hosed the thing out thoroughly with Dawn and water. A bit of scrubbing where I could get at nasty deposits, some shots of cheap carb cleaner, etc got the last of the nasty out. After everything was dry, the loose flakes of whatever were easy enough to vacuum out. A ShopVac with a short garden hose or 4ft length of heater hose duct taped to the crack and crevice tool made it easy to reach the far corners inside the tank.

The Walbro tank that is most referenced is the GSS-340. It's a 255lph high pressure pump. Unless you're running a lot of mods (power adder, NOS, supercharger, turbo) you probably don't need that much pump, and you'll probably find it noisy. http://autoperformanceengineering.co...s.html#gm_apps is a proven vendor if you want to go that way. Personally, I went to Rock Auto and ordered a stock replacement pump. If you want to get fancy the 89 Turbo Trans Am/GN/Sy-Ty pumps are drop in replacements with theoretically higher pressure/volume, whatever...

Don't use the single sided fuel pump sock filter strainer. Look for the one that's twice as long with the pump clamp in the middle. The longer strainer is the 1LE type used in all the later tpi cars, but the short single sided part is often substituted and is a downgrade.
You want the ACDelco TS18 or TS44 (4th gen).

https://i.imgur.com/N0fwMU9.jpg

https://i.imgur.com/jraEcHX.jpg

Beyond that, a new filter and a good set of injectors is always a good idea. I wouldn't mess with the rest unless it's actually causing a problem. At most I'd flush and blow out the lines.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

thanks Brian!
we have all fuel compatible fuel line..regulators, and injectors if need be. If you are interested in purchasing from us keep in mind that all tgo members receive 10% off. We'll be more than happy to help you.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

I have Southbay injectors too. ...as do a lot of us here on TGO.:thumbsup:

...I'm with Drew on flushing and blowing out the lines. I don't think there's a need to replace them unless you NEED to.

....and I'd also look into the Racetronix hotwire kit. I bought this whole kit, with the pump, and harness and everything. Granted I NEEDED more pump, but I was getting some voltage drop at the pump and just decided to get the whole thing. Basically it's plug and play, and uses the 12v from the original relay, but instead of powering that pump, it simply triggers the new relay on the Racetronix harness. I ended up bypassing the OE relay all together, but it's designed to be plug and play, and to use that OE relay if you want.

http://www.racetronix.biz/customkiti...RFPK%2D005&eq=

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Just to make sure I order the correct sending unit- How can I determine my harness code?

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Look for the tag on the harness that plugs into the body above the transmission tunnel, in front of the gas tank. Pretty sure all the later cars are going to be the same sender, only the pumps and strainers are different.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Awesome-Thanks. I think I'm going to try to go with the Spectra FG20A fuel sending unit with the Walbro GSS-340. As of now I plan on emptying the tank and cleaning/reusing it. I will blow all the lines and clean up anything that needs some attention. I will update with pictures!

-Hopefully I don't have any huge problems!

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Well not off to a good start.... I got the pump and sending unit in the mail today. And it seems that the pump and the sending unit have different electrical connections. Am I just being stupid? Pics below.
https://cimg6.ibsrv.net/gimg/www.thi...26cc2ba6a.jpeg
https://cimg7.ibsrv.net/gimg/www.thi...3157ea9e6.jpeg

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Did the pump come with the install kit (sock and pigtail ).

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Him I'll look- Do you have a pic of what this would look like?

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Just did a ebay search and came up with this.
https://m.ebay.com/itm/Genuine-Walbr...ss!81223!US!-1

https://m.ebay.com/itm/WALBRO-255LPH...oAAOSw6VRZ8Kle

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

So I need that harness- And then I use that to tie it into the spectra fuel sender... got it. Thanks man!

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

When I did mine I got the tank and sender from Rock auto. Everything went together fine. But I went with the walbro pump. Called summit and told them what pump I wanted and what it was going into. No issues there either. Wish I'd have known about the longer screen tho.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

If you got the pump kit from APE that I linked to earlier, it should have come with the pigtail. Even the Ebay Chinese knock offs should come with a pigtail. Unless you ordered JUST the pump, contact your vendor.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Look here:

http://www.racetronix.biz/items.asp?...atus=0&Tp=&Bc=

Great kit and I got mine with a power tap and harness

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Alright- Stuck again...

Fuel pump replaced, and the suspension is all still removed for cleaning/software replacement. I will address those questions on a separate post. But the car still will not fire. The engine is trying to start, but will not actually fire.
What I've done so far: Verified SAT spark by using the procedure in the Haynes manual (put distributor cable near body of car and watch the spark).
Checked that fuel is going to the engine by disconnecting the fuel line and observing fuel flow.

It seems to me that the fuel is not getting to the cylinders (clogged fuel injectors? Computer control signal? ) and I worry that the time the vehicle sat (~8 years) could have led to some clogging in the fuel rail.

Any guidance is appreciated.

Pics will follow soon! Thanks for everyone's help so far.

Jason

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Not sure why it posted twice.... damn work computer!

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

I'd put a fuel pressure gauge on the rail and confirm that you DO have pressure at the rail, and the it's good pressure. If you have that....I'd confirm the fuel is returning to the tank. I imagine you'd have way high pressure if fuel wasn't returning, but i'm just trying to cover your bases.

did you ever get new injectors? Stock 89 Multec injectors, having sat for years....ouch. ....and can you confirm the injectors are getting a fire/pulse signal? I bought a test light kit years ago, and while I rarely use it, it's proven invaluable when actually needed.
https://www.ebay.com/itm/9pc-Electro...cAAOSwsB9WCO3z

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

If you have spark and good fuel pressure. You have verified injector pulse it has to be faulty injectors.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

What do the plugs look like? If you're cranking the engine, and it's not starting, but the injectors are pumping fuel, then the plugs will probably be wet and smell like raw gas. If they've been in there during a LOT of cranking, they'll get fouled out.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Alright- I think the right course of action is to replace the Injectors, but this does get me started down the rabbit hole that I was honestly planning on attacking once the car was running. (Once the car is running I'll make a new thread I promise!)

Which Injectors?
-I think the answer you guys will likely give me is "depends on what you want..." so I guess I will really start to nail that down here.
My intention is to make it a show car (look pretty, sound good, and still function as a low end race car, although it would not see the track)
My budget is, well, ~15,000? I really don't have an overall budget but what I have is a monthly budget, so as it gets more expensive it just means I'll be an older guy sitting next to it in my $25 lawn chair at shows...

What I'd like to find is a build where someone turned a 350TPI into a ~350RWHP car and basically get their list of build parts.

For now- The injectors, this is what I was currently looking at. Please advise. https://www.southbayfuelinjectors.co...ctors-bosch-d3
Should I be selecting a higher #/hr now? Is 22 sufficient? I believe stock is 22.

Happy 4th! If any of you are in the Norfolk, VA I'm looking for a local network of Camaro nerds!

-Jason

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Those injectors may be pontiac only.... I guess I should be looking at this set instead, which is a significant price difference. Gonna have to make dinner for the wife or something if I'm to pull this one off in the next few days!

https://www.southbayfuelinjectors.co...tors-1986-1992

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

Or even....https://www.southbayfuelinjectors.co...ch-d3?___SID=U

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

You should run 22#hr injectors no need for 24s on a stock engine.
https://www.southbayfuelinjectors.co...ctors-bosch-d3 or the style you posted in post 29.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

I’ve used those style now twice (got them elsewhere, but the same) and they were a drop-in item.

Those yellow or orange Bosch III injectors, no way would I ever use.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

First and foremost, sorry for the delay. We had another baby and she their required some hospital time for a virus.

UPDATE- IT'S ALIVE!

Car now runs, but will not idle well. In fact without active gas pedal pushing it will stall out. I plan on checking fuel pressure with it running, any other suggestions?

I will start rear end/suspension overhaul next, once I close out this thread.

Says the video is too large, I will have to figure out how to compress it.

Re: 1989 IROC-Z 5.7L fuel system overhaul
 

UPDATE TO THE UPDATE: After replacing the IAC, re-setting the TPS, and checking fuel pressure I was still having issues.
Then I went to check something in the vicinity of the distributor, and it spun................
There wasn't a bolt there to be tightened to hold the cap in place.
I adjusted it about 5 degrees, and the car fired near perfectly.

......I'll time the engine and then close this thread with a video (how do you upload videos? lol)