Cooper1

Need some help!!!
I just squired this 90 iroc 305tpi we started with a lot already
new fuel pump
injectors
brake booster
drop and clean tank

it had a code for temp sensor I changed that it would start prior to and now it just won’t run starts but then pops and stahls I’m checking for a vacumn leak and I found these but no idea what they are. Two into one at distributer and a loose one on top of rt side(see in pics)
car did run prior to temp sender it did need starting fluid and ran rich to get it going but now it will not stay running.
I still need to check fuel pressure and change inline gas filter.

does any one know what this vacuum line goes to and is there supply to be a connection near the coil(pic)
any idea would be appreciated

no codes in ecm

BlksIrocZ

That first photo is your EGR solenoid. The solenoid is discontinued, and most of the time they have been cooked from engine heat after over 30 years and no longer work. There is no supply at the distributor end no that is just a coil for the solenoid, there is only two hard lines going into it as seen in your photo. There is the possibility your EGR is stuck open causing you an issue. If you have a hand held vacuum pump/gauge you can test the EGR (located underneath the plenum). Or plug the vacuum line going into the EGR and try to start it, however, checking your fuel pressure would be your first step in my opinion for sure. A fuel pressure tester is cheap to buy and well worth owning. The other line is your HVAC lines that go into your firewall.. Everyone has a different opinion but I personally always attach a fuel pressure gauge and test on a no start vehicle as STEP 1. And also ALWAYS change fuel filter after a fuel pump replacement ALWAYS.

Here is your vacuum diagram




If cars old and no known last service date. Cap, rotor, plugs for sure and wires if you like but you can ohm them out to save the $ on them if you like.

Also a side note, I highly doubt thats the issue but when it comes to sensors always try to get OEM parts AC DELCO for example. After market or chinese junk may not be in range with what you computer is programmed to see and may not throw a code, Ive seen it happen before.

Cooper1

Thanks for the reply and pic. I am going to double check all the lines.

I changed the temp sensor the car still need starting fluid to start once it started it stalled out! Now the issue is worse!! I went and bought a fuel pressure tester from harbor freight I was now under the assumption of starving fuel as it will start on a squirt of starting fluid when I hook up the guage to the fuel rail I get 0! Pressure (wtf) some duel comes out but really no pressure. I changed the fuel filter and same, fuel pump was done already. So I check power ses light is on I jumped the grey wire on relay and pump goes on I did not check to see if it builds pressure (on agenda for today) when I turn the key relay clicks and no prime.
it ran ok with a hard start and rough idle prior to, I’m stumped

would a locked up egr cause no pressure at fuel rail?
if relay clicks is it ok?

Vader

No. The EGR system has no effect on the fuel pump, regulator, injectors, etc.

After al that, it sounds as if you were able to operate the pump, so what is the fuel pressure with the pump running?

Cooper1

Somehow I got pump running but pressure drops slowly from 40 ish to 20 in about 15 seconds I pinched return line same so I think there is a leak we had rail off to do new injectors so I’m thinking an issue. Any way to narrow down from regulator/lines/injectors?
also my fuel gauge is pegged to full no movement errrr! Need to figure that out

this car was sitting for many years little by little getting it going

BlksIrocZ

Definitely a leak, if you dont see fuel leaking at your injectors onto your manifold, or underneath your car then your leaking at the fuel pump where it connects into the sending unit (rubber hose with cinch clamps), the check valve in fuel pump is faulty (cheap pump? But still should fire after long cranking) Or bad/cheap injectors leaking (will not be seen inside engine). Cheap fuel pumps (parts in general) will give you false security thinking you changed part and should be good. But again, that rubber hose that connects your pump to sending unit assembly has me wondering.

By the way, you have to be more specific. So after you jumped relay you got pressure but then drops 40 to 20? Before or after pinching return line? You somehow got it running, was this random? or after jumping relay?



Silly question, did you fill the tank with fuel after dropping the pump replacement? I helped a guy once and after all the time and effort the guy had a bone dry gas tank I couldnt believe it. He swore he "just filled it". Ill never forget it.......

https://www.thirdgen.org/forums/tech...0%2B12%20volts.

Jump ALDL port and see if ya got pressure. And of course make sure no leaks where fuel pressure gauge attaches to fuel rail.

Vader

If there is no external leak, the pump check valve may be leaking back. Fortunately, that's not a serious problem. The system has a two-second prime cycle for a reason. I had an S10 that did that when it was about 4 years old. It went another 15+ years and 200K+ miles that way and I never changed the pump, and it started every time like it should.

40 PSI is a little low but good enough. Once the engine it running, the alternator begins charging, and the system voltage is closer to 14½, the pressure should be slightly better. If you can get the pump operating (by jumper, repairing the relay or wiring, or whatever) and then start the engine, does the idle quality remain the same?