1990 GT Not Starting

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gr32
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1990 GT Not Starting

Postby gr32 » Sat Jul 21, 2018 12:08 pm

hello, just bought myself a 1990 beretta gt with 3 speed auto and got it cheap because it didnt run.

now i want to get it running, it has atleast some fuel pressure(i dont have a guage), it has spark and i think think the injectors are fireing because fuel came out of the spark plug hole. it started for a few seconds after sitting overnight and then died when i pushed the gas. no error codes on computer



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Re: 1990 GT Not Starting

Postby GT_Indy » Mon Jul 23, 2018 3:42 pm

Being a GT, I assume a v6, is it a v6 3.1?

Does it stay running if you don't press the gas pedal and leave it in park? If it can idle for a while and only dies when pressing the gas, it could be the throttle position sensor

When it runs, does it idle smooth or is it rough?

Any vacuum leaks?

Did you do a basic tune up, spark plugs, wires, air filter, check for vacuum leaks, check fuel pressure with a gauge, clean the idle air control valve, etc?


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gr32
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Re: 1990 GT Not Starting

Postby gr32 » Tue Jul 24, 2018 3:56 pm

yes, its the 3.1 v6 it only ran one time and only for about 5 seconds, idled fine then just shut off. i did not do a basic tune up but i changed oil and filter when i needed to take down the oilpan to change crank pos sensor. i checked the fuel pressure with a guage but i only had one for carburated cars up to 15 psi but it had at least 15 all the time when cranking and only dropped to 6 psi after sitting for a few days.

i did test with ether but wont do that again because it made a big backfire and i dont want to explode my engine.

i checked the computer again and only got code 12 for diagnostic mode.

im suspecting either weak fuel pump like the previus owner said or a failed injector



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Re: 1990 GT Not Starting

Postby GT_Indy » Wed Jul 25, 2018 11:25 pm

DTC - 12 No distributor reference pulse (diagnostic test active)

Did you reconnect the plug for the crank position sensor?
Is it all the way in with the bolt holding it in?
Are all the connectors connected to the ignition control module?

You need a fuel pressure tester that can read higher than 15 PSI, the rails should be holding 46 PSI when cranking. If you hold 46 PSI, the fuel is getting to the injectors. A fuel filter can help if the old one is plugged or partially plugged.

Spark tester, get one that is clear and you can see it firing. Crank and run the engine, if it stalls, restart right away look at the spark tester while cranking. If you see it is sparking and it will not fire/start, then its possible the injectors are the culprit.
It is important to find if it is ignition or fuel that is the issue.

Next would be to get a meter and check the resistance (Ohms) of each injector. See if one stands out as bad. You have to remove the upper intake to get to them and remove the plugs.

I do suggest checking the plugs, fowled plugs have been known to cause bad running or stalling.
I also suggest checking spark wires are correct.
And vacuum lines, sometimes they can fracture and cause bad running because they opened.
Pairs are in the image below:
clifford224_264.jpg
clifford224_264.jpg (9.72 KiB) Viewed 416 times


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Re: 1990 GT Not Starting

Postby DanteGTZ » Thu Jul 26, 2018 10:25 pm

This car didn't happen to come from Atlanta, did it?


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Re: 1990 GT Not Starting

Postby gr32 » Sun Jul 29, 2018 9:12 am

DanteGTZ wrote:This car didn't happen to come from Atlanta, did it?

no been in sweden all its life :D

done some more diagnostics and im starting to suspect bad ECM the ecm gets 12 volt, ground and reference signal from the ICM, the box gives out 8 volt pulses to the fuel injectors and i dont think thats enogh to trigger them. i didnt bother to ohm test every injector as i dont think thats the problem but i did measure the 2 banks in the harness connector and they both where around 4 ohms as they should be.

before buying a new ecu im going to go over all ground points on the car but i didnt find a good diagram of where they are and how many



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Re: 1990 GT Not Starting

Postby GT_Indy » Mon Jul 30, 2018 2:52 pm

gr32 wrote:
DanteGTZ wrote:This car didn't happen to come from Atlanta, did it?

no been in sweden all its life :D

done some more diagnostics and im starting to suspect bad ECM the ecm gets 12 volt, ground and reference signal from the ICM, the box gives out 8 volt pulses to the fuel injectors and i dont think thats enogh to trigger them. i didnt bother to ohm test every injector as i dont think thats the problem but i did measure the 2 banks in the harness connector and they both where around 4 ohms as they should be.

before buying a new ecu im going to go over all ground points on the car but i didnt find a good diagram of where they are and how many


Engine has ground points on 2 of the bell housing bolts. One front one rear.
Battery grounds to body on driver side and to engine and front bell housing bolt.

There is a ground strap (I remember one) on the rear side of the engine to the body. I don't recall exactly where on the body that connects.

I've had an ECM go bad in the past, they are easy to swap, just remember to keep the EEPROM chip and swap it into the new ECM box.
Should be the 1227730 ECM for the 1990 Beretta GT.

I have a 1990 service book so I can try and look up specs if you need.

I've also had injectors fail in the past where it ran for a bit and died right away. Depends on how the parts failed.


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Re: 1990 GT Not Starting

Postby gr32 » Mon Jul 30, 2018 4:18 pm

okay, now it runs finally :D it was the front most ground strap right under the air cleaner. should have really checked it before taking down the oilpan to switch CPS. but atleast i got fresh oil in it now. thanks for the help and tips :D



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Re: 1990 GT Not Starting

Postby GT_Indy » Tue Jul 31, 2018 7:26 am

gr32 wrote:okay, now it runs finally :D it was the front most ground strap right under the air cleaner. should have really checked it before taking down the oilpan to switch CPS. but atleast i got fresh oil in it now. thanks for the help and tips :D


Wow. I wouldnt have thought that a ground would be doing that. Was it the battery ground that came off?
At least it was an inepensive fix.


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Re: 1990 GT Not Starting

Postby gr32 » Fri Aug 03, 2018 3:28 pm

ok looks like that was not the problem after all, but atleast i found a temoporary ay to get it to run. while i was working on the ground i also clicked the injectors a few times to see if they where working. that must have unstuck a sticky injector or something and made it run. either that or bad ecm box im suspecting now.

im thinking the stuck injector is drawing too mutch current and dropping the voltage in the ecm signal to 8 volts or the ecm has failed not being able to deliver enogh current sometimes.

ive added some injector cleaner fuel addative and fillled it up with 98 octane (atleast made it to the gas station :D )

i would also like to add that the car has been sitting for a few years before i bought it



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Re: 1990 GT Not Starting

Postby GT_Indy » Tue Aug 07, 2018 9:57 am

Yah cars that sit for a few years, things start to stick and degrade. Its possible you have partial plugs from old fuel gumming up the system.
I dont know if higher octane helps, the compression isn't super high, but the injector cleaners will help.

There is a product called marvel mystery oil. Its supossed to be like magic as far as cleaning out and lubercating an engine.
https://www.reference.com/vehicles/marv ... c7beef758d

There is also lucas but lucas can plug up and ruin O2 sensor with extended and heavy use. I think lucas is more for prevention than anything. However they do sell a fuel system cleaner which I have not tried myself.

There is seafoam. I used it in the past. It works very well as a fuel system cleaner.

There is also fuel stabilizer. But it's more for prevention and prolonging the life of gasoline if a vehicle sits.


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Re: 1990 GT Not Starting

Postby Rettax3 » Tue Aug 07, 2018 4:35 pm

Seafoam is a good product. For a 'restorative' rather than 'preventive' fuel system treatment though, I would say replace the filter and go for a can of Barry Grant "BG 44k", if you can get it -most effective treatment I've ever seen used.

I bought a '90-something Camaro from a co-worker a few years back, and all six injectors were bad. Two didn't fire, one dribbled constantly, and the other three had very poor spray patterns and flow. The car ran great after I replaced them (for a V-6 Camaro, at least), but it was a little tough to diagnose because the Ohms were within range on both banks (IIRC), and such a complete failure seemed unlikely at the time. I also had both injectors fail on the '89 Caprice Police Special 350 I put in my '89 RS Camaro, and it took most of the day to determine I hadn't screwed something up on the wiring-harness transplant -both injectors fired perfectly when touched with battery voltage directly, but the pulse of the ECM was too short to unstick them.

If the car has been sitting that long, I would strongly consider new injectors with the symptoms you have. Remember, the injectors receive full battery voltage directly with the ignition switched on, the ECM just grounds them through the blue and green wires in micro-second pulses to regulate fuel flow. If the ECM's ground is bad, it cannot ground the injectors even if it is working correctly. I've been watching the Boards long enough now though, a huge percentage (relatively speaking) of European-based Berettas have been experiencing ECM failure over the last four or five years -most of the major running and driveability problems reported here seemed to be ECM-related... I guess the simpler issues don't get talked about as much though, so my data is anecdotal at best. :pardon: Good luck, keep us posted. Any pics of the car? I love the '90 GTs... :good:


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