I have a 1989 formula 305 TPI that i believe was swapped to a 350 SBC, I checked the block number and it was 10054727 which showed as a 350 SBC from 86+. Now, when I bought it started, albeit with a bit of cranking. I swapped the plugs, ICM, fuel pump as the check valve went bad(pressure bled off instantly) and the fuel filter. It is still not starting without fluid, I checked my grounds and the motor sounds like its got a cam in it, the guy had the pump wired directly to a 12v source so I fixed that wiring however It still wont start without a little fluid, then it will run a bit rough with a misfire from what I can tell(engine rocking back n forth, a bit of inconsistent idle). My TPS is reading 0.54 volts, I am wondering if its the injectors are dirty or if the owner swapped the 19lb injectors from the 305 TPI onto the 350. I was also wondering if it could be the starter motor, as its the OEM motor and it had overheating issues before. I purchased an LT1 starter which should come tomorrow, I can tell the starter is on its way out anyways so I decided to replace it regardless if its my issue or not. Any Assistance would be apprecited, thank you

 

What's the fuel pressure? What's the part # on the injectors?

 

Fuel pressure is about 50 psi, no idea the part # on the injectors, cant ask previous owner as he is dead.

 

It's printed on em.

 

I cant really see anything, except maybe a 9, so if I wanted to look at the part # if its there i'd have to remove the injectors to do so.

 

Nobody out here can see them either. Only you. Sux that it requires effort butt that's Just The Way It Is.

I guess it comes down to, whether you want to figure out why your car doesn't run right, or not. "Internet fix my car for me NOW while I do nothing!!!" can only get you just so far.

 

No need to be a dick bout it, I am trying to diagnose the problem before I start ripping into it, seeing if anybody has any other ideas besides the ones I currently have. Just wanna know if the 19lb injectors would prevent the car from starting but allow it to run.

 

Yes. They would deliver inadequate fuel. Which is why step #2 listed above, is to identify them.

 

Always multiple reasons for your problems. Answer asked questions so proper repairs can be completed by isolating what's not causing the problem. It's no different than phoning your doctor and saying "It hurts when I do this". Without a lot more information, you're not going to get a very good diagnostic.

 

I believe what the inquiry was attempting to establish was if the injectors are appropriate for the engine displacement. I've done 305 to 350 swaps and used 305 (19 lb/hr) injectors, but had to burn a PROM with a corrected injector constant. If the previous owner just bolted the 305 TPI onto a 350 as you eluded, the difficult start could be a result of the "light" injectors.

Also, the '89 model year did not have the cold start injector present in previous models. This could also adversely affect the cold starting since all fuel is applied by the service injectors alone.

If you could disconnect the electrical connector and spin the injector(s) in the mount, the part number might be more accessible. The O-rings should tolerate it.

 

Alright thank you, that is what I was trying to convey although I am not the best at explaining my thoughts over posts like these without being able to elaborate. The part # on them were 5235435 which came up as the 305 injectors, so I will replace them once I get the new injectors, I just dont want to leave any part of the engine open for too long/the car unable to run due to our neighbors and the hoa(they do not rock with me ). I also would like to confirm if I am correct in the block # being 10054727 meaning its a 350 block, I already checked the list of block codes but thought I might as well ask to get a second source on it. What are some good injectors, and would I need to get a new chip, or could I get away with just the injector swap for now. Thank you for your assistance.

 

Have you opened up the ecm to see what chip is installed ?
southbay has a father’s day sale use southbay at checkout. I’m not sure but think their delphis are not available at this time but D3 with a tune work well.

 

I opened it up a bit ago cause I wondered if the chip could be the issue, I couldn't find much info at the time but I believe it was the stock 305 ecu and chip. I can open it up again and double check. Found some bosch ev1's on marketplace, would those work well enough without a tune. Asking cause they are cheap, would check resistance vals when i go and get em.

 

Unless they have recently been serviced it’s a crap shoot. Might as well do it once and with the right parts. Most 88 bcc are listed here

https://www.3rdgenformula.com/89/promcodes.htm

 

Just a thought... If you're already at 50psi, the assumption is you have an adjustable fuel pressure regulator. You need ~59psi to make those 19 p/h flow 22 p/h.

 

is the fuel pump priming with key on/engine off? if the previous owner hacked up the fuel pump wiring, i wonder if you somehow lost the ecm priming signal. does it eventually clear up and run right or does it run rough indefinitely? i would do a fuel pump pressure and bleed down test as well, verify what injectors you have on it.

it sounds like you’re fighting two issues honestly. i don’t think a cammed 350 will run well at all on a 305 prom and injectors but it shouldn’t need starting fluid to start.

 

BINGO. This is worth a look. I also think that it should start and run on 305 injectors. *I* would start by checking to see if the fuel pump is priming...I'd wonder if it's only running on the oil pressure switch after firing on ether.

 

I fixed the guys wiring, he ran a wire from a 12v source in the fusebox and cut the weatherpak to supply 12v directly to the pump, I reconnected the weatherpak wiring to rule out the wiring being wack. I decided to recheck fuel pressure before replying, however my thought on the starter being too weak appears to be correct, swapped in a new smaller starter and it will start without fluid, will occasionally grind so need to check voltage. However when i first primed it, the PSI was about 20-25 psi and then I jumped the fuel pump relay and it show back to about 40, released the pressure to see if it would happen again and it just shot back to 40psi, bit wacky. However when I started it the PSI fluctuated around 35-40psi but stayed closer to 35psi. It still has the weird surgy idle and shaky shifter, and it will eventually settle to around 900rpm, but I can still hear what I believe is a misfire, and the engine still shakes side to side. I attached two videos showing starting the car and how the fuel pressure and idle change + the engine shaking from side to side. Apologies for the last response it wouldn't let me reply, though glad I rechecked the fuel pressure! I do think im fighting more than two issues, but more issues = more things to fix = more fun

 

35 psi is about right for idling with the vacuum line still connected to the FPR like you have it. With the vac disconnected it should be around 43.

As a side note: the amount of fuel actually delivered into the intake, is dependent on the pressure drop across the injector. That is, the pressure on the fuel side of the injector, minus the pressure on the intake side. Atmospheric is about 30 inches of mercury; when a typical stock-cammed car is idling the vacuum in the intake is around 15 - 18 inches; therefore manifold pressure is roughly half of atmospheric pressure or a little less. Atmospheric is 14.7 psi more or less, so half that, is 7½ psi. For the ECM to not have to make any adjustment whatsoever to the pulse width then, the FP must track manifold vacuum by exactly the amount that the pressure inside the manifold changes due to vacuum. If your idle vacuum is 16 inches, then the pressure in there is right at 8 psi lower than atmospheric, meaning the FP should be lowered by the same 8 psi to keep the fuel delivery identical without requiring further electronic correction. A pretty simple and convenient relationship. Note how in your movie, as the idle RPM falls and the vacuum decreases, the FP rises, due to the action of the regulator.

Looks to me like your fuel system (pump, FPR, etc.) is working properly.

Your tach is reading at least 30% higher than reality; probably more than that; hard to be sure exactly. IOW, failed in the same way everybody else's is too.

 

Alright thank you, for my engine shaky/ surgey idle I assume it might be either a timing, spark or motor mounts, the plugs are new but the wires are not, I tested their resistance before and they were all within spec and all showed spark when using a spark tester, however I did get zapped when going to adjust one of the wires, so I've been meaning to replace them. Once again thank yall for your assistance, still gotta fix the guys weird AC delete and other things, but trying to make sure the motor is fine before any non-crucial things get my attention.

 

NOT "timing". Could be spark on the high-voltage side (plugs, wires, dist cap, rotor, coil). Not engine mounts. Could even just be, too much cam (or just, inappropriate cam), wrong injectors, no exhaust, and no tune. Several details to sort out there.