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Won’t start after new injector install

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Old Jun 7, 2019 | 09:51 AM
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dorrifto dorrito's Avatar
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Won’t start after new injector install

Hey so this has been a couple day long adventure.
I installed these things all at once:
new injectors (stock replacement from ebay, I have a stock ecu and all)
new air filter
new spark plugs
egr delete with plate

Upon first install, it would start up every time but not stay on
I then realized I never put on the spacer that goes between the block and the primary fuel rail mount, its two bolts going through the spacer
So I take it all apart again, reinstall with spacer, no longer crushing the injector grommets due to lack of spacer
cool
fully reinstall everything
now it wont start
teardown and reinstall again
still no start
constant flooding when attempting to start

if I unplug the fuel pump, the car will almost/pretty much start for a second as it burns out all the flooded gas. plug the pump back in and it just floods again.

I already checked to make sure injectors arent stuck by testing each one with alligator clips and battery.

Injector diffusers were cleaned and theres a new o ring and grommet on each injector. using old injectors’ spacers.
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Old Jun 7, 2019 | 10:23 AM
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Does it hold fuel pressure after turning off the fuel pump power?

Last edited by RXSpeed16; Jun 7, 2019 at 10:26 AM.
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Old Jun 7, 2019 | 10:59 AM
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Originally Posted by RXSpeed16
Does it hold fuel pressure after turning off the fuel pump power?
yes i have a gauge installed and it stays at 39 if i unplug the pump. I can get it to go to 0 if I unplug the pump and fire off whats in the chambers but once I replug and try to start its a no go.
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Old Jun 7, 2019 | 11:11 AM
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I got it to turn on again by unplugging the fuel pump, getting it to start firing whats already in the fuel system, then having a friend plug it in at that point. kinda like a killswitch. will turn on like that, runs rough, and dies if i get off the gas
could have fucked up the timing
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Old Jun 7, 2019 | 11:22 AM
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engine shakes a TON under 1k rpm if i let it go that low
it used to idle comfortably at 750
now i cant get it to stay on?
feels like maybe not enough air or idk
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Old Jun 7, 2019 | 11:31 AM
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another update
I managed to get it to stay on for a bit by using the throttle stop adjust to let more air in to have a higher idle since the lower idle was not holding. used that to check timing with a light and get it to tdc (yellow mark) and still super shaky
will still die if i rev it, can try to get it to idle at like 1200 but then any throttle use kills it

does anyone have any tell tale signs / symptoms of running on one rotor so i can verify an injector isnt firing?
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Old Jun 7, 2019 | 11:59 AM
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dorrifto dorrito's Avatar
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alright so i pulled the lead sparks and the front rotor one was a bit fouled-brushed it off
rear was COMPLETELY clean so my rear rotor must not be running?
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Old Jun 7, 2019 | 12:31 PM
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You might have damaged the grommets when you forgot the spacer causing a vacuum leak. If you can keep it running, shoot some carb cleaner in there.
Double check the wires are going to the right plugs and re-stab the CAS to set your timing. You can't trust the timing light right after starting or at high idle.
Do the usual check for vacuum leaks at hoses and intake piping connections.

The clean plugs would be the non-running one. If it's dry, look into the wiring to the injectors. Try to actuate them from the pins at the ECU.
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Old Jun 7, 2019 | 01:00 PM
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Originally Posted by RXSpeed16
You might have damaged the grommets when you forgot the spacer causing a vacuum leak. If you can keep it running, shoot some carb cleaner in there.
Double check the wires are going to the right plugs and re-stab the CAS to set your timing. You can't trust the timing light right after starting or at high idle.
Do the usual check for vacuum leaks at hoses and intake piping connections.

The clean plugs would be the non-running one. If it's dry, look into the wiring to the injectors. Try to actuate them from the pins at the ECU.
alrighty i fixed it
just a connector with a prong too deep in on the leading injector for the rotor with the clean plug

while im here, im setting my timing again now and i always wonder why it tries to bog as i approach tdc? this is with timing light and turning cas by hand

setting timing is always really weird with this car and takes many tries
initial set coupler jumped or not
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Old Jun 7, 2019 | 01:06 PM
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From: NYC
Originally Posted by dorrifto dorrito
alrighty i fixed it
just a connector with a prong too deep in on the leading injector for the rotor with the clean plug

while im here, im setting my timing again now and i always wonder why it tries to bog as i approach tdc? this is with timing light and turning cas by hand

setting timing is always really weird with this car and takes many tries
initial set coupler jumped or not

will only stay on if i advance the timing
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Old Jun 8, 2019 | 01:26 AM
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dorrifto dorrito's Avatar
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update:
reinstalled with very well oil lubricated o rings
they slipped on great
fixed connector on injector so i believe both are firing, ill check plugs later
however it still wont stay on after warmup! fires up every single time and goes through warmup cycle then slowly idle drops and dies once it gets near spec
i am sad man, doesnt seem to respond to timing changes or idle changes
just fires up n dies once warm
if already warm it will fire up to 3k and then die immediately
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Old Jun 8, 2019 | 02:34 AM
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dorrifto dorrito's Avatar
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woop nevermind i think i got it
had to set idle super high (1.2-1.5) for it to stay on long enough to time and now i just have to lower idle. gonna sleep finally though. have taken uim off 6 times in last 30 hours lol.
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Old Jun 8, 2019 | 08:17 AM
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Couple things bud,

- Still sounds like a vacuum leak is a likely culprit. You can seal off one end of the intake, and use a small amount of compressed air (10-15psi max) to find them. They can leak around the injectors, like RxSpeed said, or you might have forgotten to hook something back up. If things aren't hooked up correctly, you could get one rotor getting proper mix, while the other doesn't.

- Have you checked the spray pattern from the injectors? Those old pintle cap style injectors sprayed a jet of fuel that splattered against a diffuser down in the manifold (think cow peeing on a flat rock). If your pattern is off, your fuel dispersion could be messing with you a little bit.
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Old Jun 8, 2019 | 01:57 PM
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From: NYC
Originally Posted by professionalpyroman
Couple things bud,

- Still sounds like a vacuum leak is a likely culprit. You can seal off one end of the intake, and use a small amount of compressed air (10-15psi max) to find them. They can leak around the injectors, like RxSpeed said, or you might have forgotten to hook something back up. If things aren't hooked up correctly, you could get one rotor getting proper mix, while the other doesn't.

- Have you checked the spray pattern from the injectors? Those old pintle cap style injectors sprayed a jet of fuel that splattered against a diffuser down in the manifold (think cow peeing on a flat rock). If your pattern is off, your fuel dispersion could be messing with you a little bit.
i cleaned rhe diffusers and i triple checked everything being hooked up. it bogs after warmup cycle. got a lot of misfires and again its hard to get timing right without advancing so probably a vac leak honestly
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Old Jun 8, 2019 | 10:43 PM
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Originally Posted by dorrifto dorrito
i cleaned rhe diffusers and i triple checked everything being hooked up. it bogs after warmup cycle. got a lot of misfires and again its hard to get timing right without advancing so probably a vac leak honestly
gonna try to buy a 1-200$ auto smoker off amazon to test for vac leaks

i can get it to yellow timing mark with a timing light only if i raise the idle with throttle stop as i do it. if i get the idle low first and then try to get proper timing it always bogs as i get to/as soon as i’m at yellow mark
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