No fuel injector pulse

35th

Registered User
I have a 90 SC 5sp The harmonic balancer broke so I pulled the engine to fix that and multiple other small issues. Did not pull the SC or fuel rail just did gaskets harmonic balancer and those sort of things so I've got the motor back in the car and can't get it to run. I'm getting spark and compression if I spray ether it'll run as long as there is ether but it will not try and run on its on I checked all connections and I'm not getting any sort of pulse at any of the injectors I've checked the ground on the rear of the drivers side head to goes into the wiring harness and it's good I did notice that I don't get a cel when I turn the key on I can hear the fuel pump running and I've got 32psi on the fuel rail so fuel is there just isn't being injected I'm thinking possibly eec but don't know why it would have went bad it was fine before the harmonic balancer broke any help would be greatly appreciated
 
I've got the motor back in the car and can't get it to run.

Did you reinstall the ground strap from the pass. side motor mount over to the body?

Do you have +/- 5 volts at the ACT sensor with key on?

Does the car have an alarm/anti-theft system?

I know that with the throttle held to the floor while cranking, the injectors are shut off, but I'd have to EVTM to trace that circuit. Do you have an EVTM, or do you want i should dig thru mine ('90).

Odd you don't get any codes, I think...

Seen this thread? http://www.sccoa.com/forums/showthr...no-injector-pulse&highlight=no+injector+pulse - the OP claimed no fuel pressure, tho, so not exactly your issue.

I'd go back over the fuel injector harness, all the way to the multi-wire connector pass. side firewall near the ABS relays. Might need to do a voltage drop test across that connector; confirm continuity thru the injector connectors.
 
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Yes certainly reattached the ground on pass side and I do get 12 volts at the injectors just no ground to make them pulse forgive me for not knowing as I'm new at this type of issue but you said +/- 5 volts to act... What's act stand for not familiar with that. And the other ter evtm or something of that sort not sure about that one either this is the 4th day I'm working on resolving the problem so the wot cutting the injectors wouldn't be present for that long so I don't think that's it also with a stehascope I can't hear the injectors clicking at all. And I do thank you for trying to help me with this
 
And I forgot to answer there is no alarm that I'm aware of just got the car 2 years ago but haven't driven it more than 300 miles bought it with a destroyed trans got that in and was driving it when harmonic balancer went
 
ACT is the air charge sensor on the intake - if you aren't familiar with it, don't worry about it now.

EVTM is an 'Electrical and Vacuum Troubleshooting Manual', a must have for the SC owner, check eBay, be sure to get one for your year car.

Moving on...

How long have those injectors sat without being used?
 
Act is new haven't checked voltage I'll definitely look into the book and roughly a year
 
With the key off I get ground at the injector plug key on volts I'll test from battery to regular when I work on it next maybe Fri
 
You may need to check resistance across both pins at each injector - 9 ~ 16 OHMs is normal, I think.

See the discussion here: https://dannysengineportal.com/engine-will-not-start/

Might be a shorted injector is shutting down the ECU's ability to send a pulse to all of them; might be the ECU has issues of it's own.

Did you have the ECU out/disconnected during the last repairs?

Again, how long have those injectors sat unused?
 
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No I didn't disconnect ecu or have it out. That I'm aware of it's never been out I've had the car almost 2 years and I have not disconnected it or anything the harmonic balancer broke in Dec. 2018 started trying to crank it after repairs last Friday so almost a year
 
Doesn't matter because the connector will be pulled.

Remove each injector connector, and test ohms across each injector's terminals at the injector, individually, just like if they were out of the car and on a workbench. Pls. be careful puling the connectors to avoid breaking their tabs - given the age of our SCs, all connectors can be brittle and break easily.

If one or more show anything other than 9 ~ 16 ohms, there may be a problem.

If the injectors have sat for two years, they may be stuck/gummed up inside. If that's the case, they'd need to come out and be sent for cleaning/service.

I've got 32psi on the fuel rail

Might be low. Check the rubber vacuum line at the fuel pressure regulator and see if you can find any wetness/raw fuel.
 
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Rather than unplug each connector could I unplug the harness and test from the back of the connector or would that read all the injectors being they would still be wired together? Trying to ensure I don't break the brittle connectors
 
The information I'm looking for requires removing the connector/working on each injector in isolation.

But before you do that, check for raw fuel at the vacuum line on the fuel pressure regulator. As I said, 32 psi key on is low...I'd like to know why. I'd expect 40~42 psi key on, engine off.

If you're seeing an accurate/reliable 32 psi, then there may be a pump/supply issue, or an injector hung open/leaking, or?. Do you smell fuel? Is there any indication of raw fuel in the engine oil/on the dipstick? How old is the fuel in the tank?
 
No indication of fuel in cylinder or oil fuel is fresh drained the tank when I pulled the engine as I wasn't sure how long I'd have the engine out for refueled 5gallons after reinstall
 
Good evening

There is another ground to check. 1989 - 1990 3.8L engines harness have a ground connected the back side of the driver side cylinder head.
 
Good evening

There is another ground to check. 1989 - 1990 3.8L engines harness have a ground connected the back side of the driver side cylinder head.

Yes I checked that ground it's hard to get to but it's clean and tight
 
Good morning

My fault I skipped over Post #1 cylinder head ground statement. You can buy and or rent a fuel injector "noid" light kit to verify fuel injector connectors are receiving EEC pulse.
 
So I want to personally thank everyone who joined in to help me I'm sure that your time is valuable and it's also appreciated very much I did fine the problem and I am an idiot because I didn't connect the ground wire next to the battery near the headlight found that today car fired right up but unfortunately for me looks like I'll be doing head gaskets now cause the oil pan is full of water not sure how it blew never been over heated wasn't blown before but it is now so guess I'll be tackling that issue real quick has anyone ever seen thr oil cooler leak antifreeze in the oil?
 
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