I have an 1985 corvette which needs a serious tune up. I want replace the injectors but not sure with what. It is my understanding the stock injectors are 24lbs. that operate at a reduced fuel pressure rate of 38psi in order to pass emission testing back then. I've been told to go with 22lb. at a higher pressure of 43lbs. This setup is the same amount but offers better atomization. Makes sense to me but want to know if there any looming computer/sensor operation issues with the new setup with the 1985 electronics. Help!!!!!! This car hasn't been run in 4 yrs and needs attention. Thanks in advance.

 

85 were bosch i think. personally ohm test them and if good id get the original ones cleaned and keep everything stock. u can clean them yourself diy if you search youtube.

your 85 injectors were not junk like the multecs that came later.

u can also call fic, fuel injector connection

 

I did call Fuel Injector cConnection and they recommended the 22lb. at the higher pressure. They spoke highly of the stock injector but said it was used due limited options as GM scrambled to get rid of the CFI. They were Bosch injectors, I beleive EV1s.

 

A friend put Accel 24s in his stock 85. Runs good

 

I cleaned, ohmed, and put new orings and pintle caps on my 85 injectors. I also “spray tested” them using carb cleaner and a 9v battery. They checked out ok, so I reinstalled them and they work great.

 

i did the same, curious why u used 9v vs 12v?

 

Because I had a little 9v battery handy. It was plenty of voltage to actuate the solenoids.

 

good to know. did u use the “fifty five ford” method on youtube?

 

It might have been. It was about a year ago, and I did watch something on YouTube. I used a rubber hose to connect the carb cleaner straw to the feed on the injector and then opened the solenoid while spraying cleaner. This showed me the spray pattern while cleaning the inside of injector.

 

Planning on cleaning injectors myself using same method. Before I try I'm going to confirm fuel regulator is good. If not, I'll see if the '85 regulator is available. If not, I might go with 22lb. Injectors with '86 Regulator for the higher psi.

 

Started tear down and cleaning for new injector install. I went with 22lb bosch with the 43lb (1986) regulator. One thing I'm shock at is how much carbon/dirt is in the intake runners and manifold. The injectors were super dirty. Everything before the intake manifold will be spotless. The intake, however, is bad. The injector passage is filled with crud where the injector oring stopped. Anybody have suggestions on how to clean without getting crap falling into motor? Almost thought about off intake manifold but hate to to that.

 

That is the best way unfortunately. I took mine off and had it hot tanked and milled at a machine shop. It was like new when I put it back on. YMMV.

 

might want to pull the intake , I thought 85 used 24#hr injectors at a lower pressure The stock fuel pressure for with TPI was 36-39 psi . So with 22#hrs at 3 bar you would need a afpr you would be at a super high 52psi. Or adjust tuning maf tables and injectors offsets the D3 run lean. Might not be worth the effort to tune a old 2732 prom and just get the right injectors.

 

I decided to take off the intake manifold. I'm curious whose gasket kit you used and if the kit had seals at the front and back between the manifold and block? Or did you just use RTV black? I'm looking at the Fel-Pro kit but there are several to pick from.

I dont plan to mill the manifold. Why did you decide to mill it?

 

I used the FelPro intake manifold gasket set for my year 1989. For the 1985 model, the kit number is MS 93035-1. I used GaskaCinch on the water port surfaces of the head and intake manifold front and rear. It helps to hold the gasket in position when you place the manifold on, and IMO it helps the seal also.

It does not come with a front/rear China Wall seal, you are advised to use RTV silicone for that. I used The Right Stuff black RTV, the non-pressured toothpaste tube kind, and it worked perfectly. No leaks afterward. You must ensure that the china wall is clean and dry, no oil residue or old RTV left on the sealing surfaces. I used brake cleaner on a rag for that.

I decided to mill mine because the OEM manifold had some corrosion and aluminum pitting near the water jacket sealing surfaces, and I had experienced small leaks there previously. So I wanted the best new sealing surface possible. It worked.

 

That's the kit I was going for. I will order tomorrow. Thanks!

 

I bought reconditioned injectors. The nu.bers off the injector is 0 280 150 943. I found a chart that said these are 18.5 lbs/hr. They were advertised as a 22lb. injector-3 bar. The injector coming out of the car is a 0 280 150 223. I think it is a factory 85 24lb. Injector which I understand puts out 22lbs. at the lower fuel pressure of 36psi. Not sure the 0 280 150 943 flows enough at 43 psi. Am I wrong?

 

Maybe fic drilled them for higher flow, not sure I’d try them but I guess they have a warranty if not right.

 

my 2-cent opinion, FWIW -- first, "hands-on" experience with 85's and bosch injectors. originals were first generation bosch - definitely a good injector. i cleaned mine several times before going to 24 pound gen-3 bosch injectors from FIC. i agree, a smaller 22 pound injector, at the same or higher pressure maybe a better combo and may spray and atomize better - i once read 19 pounders are even better yet. GM went to 22 pound injector on the L98's in 86 when they switch from bosch to multec. not sure of the correlation, but they must of had a reason (besides saving a buck , must of had something to do with aluminum heads, fuel economy and/or EPA regs - my money's on the EPA ). early multec injectors were problematic due to the ethanol gas screwing with the injectors internals. multec's manufactured after 1994 don't seem to have that issue. first generation bosch injectors have a single port spray nozzle whereas gen 3 and 4 have multi-port spray nozzles. by design, they will spray and atomize better. my advice - unless you have an adjustable fuel pressure regulator, stick with the 24 pounders, upgrade to gen 3's from FIC. and don't try to out-think the factory. if purchased from FIC, they come as a matched set - flow rate, spray pattern, coil resistance, etc.. unless you have some 100 point show car or museum piece, i wouldn't sweat the originally stuff. i've been running bosch 3's in my 85 for years - no problems or issues. again, my opinion....

 

personally, i think you 've gone into information overload. your car, engine, and software was designed to use bosch 24 pound injectors within a factory (fuel) pressure regulator window at that point in time. contrary to the experts and IMHO, DON'T TRY TO OUT THINK THE FACTORY!