1988 beretta 2.8L

[timhunt24]

I have a 1988 beretta 2.8L which runs and starts fine when cold. Once it gets to operating temp it hesitates and stalls, but fires back up 5 to 10 min later. I have changed everything with fuel,oxygen sensor,speed sensor,and mass airflow sensor. I would hate to junk the car because it only has 65,224 miles on it. If anyone could help i would gladly take it because its making me mad lol. thanks all.

[Airjer_]

Check the resistance of the injectors after it stalls. They should be at thirteen ohms if memory serves correctly. If one of them goes bad it will cause the whole bank to go dead. This was a super common scenario back in the day of the early 2.8/3.1's.

[timhunt24]

i have checked and replaced the fuel injectors also. if there is any other idea or thoughts let me know asap. thanks all

[Airjer_]

What are you missing when it wont start? Do you have spark? injector pulse?

[jsgold]

When the igniton modules on these start to fail they will act up when hot. My advice is remove the module and coils and have the module tested. Could even be crank sensor. Test for fire after it stalls too, should be able to generate a 3-4" BLUE spark. A yellow one or smaller one might be an indicator too of a weak module. Sometimes the tests on the module show OK when it is cool, so not a 100% accurate test sometimes. Advance, NAPA can test them.

[timhunt24]

its hard to say what im missing when it doesnt start after its hot. i have pleanty of spark and really confused, before all this started the car ran great execpt when you mash on the gas it would die, but if you gradually work into speed it would be okay. but now this problem comes up when it gets hott it sometimes dies or it chokes and hesitates to go.

[jsgold]

See if you can borrow a fuel pressure tester and see what the pressure is both cold and hot. And remove the module and get it tested. I know a fellow with a 3.1 that had the module failing and the crank sensor at the same time. It ran great until it got hot then off it went. But you could have a fuel pressure problem too.

[manicmechanix]

Maybe you are losing injector pulse when it stalls and won't run. If you unplug the main injector harness to the ECM And apply A test light +B to the ecm side of the connector is should flashes during cranking. It's also possible your ICM is not providing the reference pulse output to the ECM. You can have spark even without a reference pulse to the ECM. Somewhere you are losing electrical contuniuity in a circuit.

[fwttg]

Hey guys, hope you don't mind me asking a question related to your comments. I have a similar situation with a Corsica (thank manicmechanix for your response at http://www.automotiveforums.com/vbul...d.php?t=953934).

jsgold describes a 3"-4" blue spark. The spark I'm getting is better described as the yellow one although it is the same hot or cold. Can you give a brief description of your testing technique? I'm holding the plug against the motor.

I was leaning towards the injectors needing replacement because on the V6 each bank was showing about 3.8-3.9 ohms when hot and I get spark but the wait to restart is dependent on the vehicle temperature at stall ie: the hotter the engine, the longer the wait.

Good luck timhunt24. Please keep us updated!

[jsgold]

Very basic test...I just unplug each plug wire and see how far it shoots to a metal source in the engine compartment. I have a cheap tester that can do this as well I bought at Advance Auto but this works for me. The last time I did this I found one coil in bad shape and one weak but funtional. Coils are only 20 bucks each so went ahead and replaced all three.

[manicmechanix]

Originally Posted by fwttg

I was leaning towards the injectors needing replacement because on the V6 each bank was showing about 3.8-3.9 ohms when hot and I get spark but the wait to restart is dependent on the vehicle temperature at stall ie: the hotter the engine, the longer the wait.

On the vin T engine the injectors are all wired in parallel, so you are measuring all 6. I think the spec is 4-5 OHMS so you are borderline there. At the injector mini connector you should have positive battery voltage at the engine side and on the ECM side of the connector it should flash a test light to +Battery voltage when cranking. If you have power to the injectors and the ECM is pulsing them, getting spark, and fuel pressure then it really looks like your injectors are cutting out. I don't want to tell you to put new injectors on but they are known to act up like that. To measure the resistance of each injector which should be around 12.2 OHMS, you'd have to take the plenum off.

[fwttg]

Thanks for the follow up. I ended up testing the individual injectors. They range from 12.6 - 13 ohms and there is battery power to them. Fuel is good to the rail and spark is healthy on cylinders 2,4,6. I'll confirm 1,3,5.

The next step will be to check for pulsing from the ECM. I expect a problem there because other items on that ECM circuit (fan, EGR, CEL) seem to cut in and out once the vehicle is hot and stalls.

The time to stall is consistently around 10 minutes and it is like turning the key - it just stops, no stuttering, coughing, misfires etc.

[manicmechanix]

Originally Posted by fwttg

The next step will be to check for pulsing from the ECM. I expect a problem there because other items on that ECM circuit (fan, EGR, CEL) seem to cut in and out once the vehicle is hot and stalls.

The time to stall is consistently around 10 minutes and it is like turning the key - it just stops, no stuttering, coughing, misfires etc.

Yeah you definitely want to check the the ECM is pulsing the injectors. The symptons that you are describing now sound more like a a wiring problem or ECM ground or maybe the ECM itself.

[fwttg]

My apologies for hijacking this thread but jsgold and manicmechanix were good enough to respond and I wanted to follow up. Mods can advise if a new thread should be started.

Spark, fuel pressure, injector resistance and injector pulse all seem to be OK at stall. The only issue I can grab on to is various components, including the CEL, cycling off and on erratically at stall with the key in the on (not crank) position.

So replaced the CTS and this time the engine started sputtering as the fan came on and the CEL captured a code 14. I shut down the engine once I saw the CEL so I don't know yet if the engine would have stalled. Anyway, code 14 seems to be a faulty CTS circuit or ECM. I don't know if the cooling system needs checking or the thermostat needs replacing but they're not mentioned in the fault code description.

I'm going to try rewiring the CTS-ECM circuit and then I guess it's ECM replacement time unless anyone has suggestions!

[MrAnon]

Is the "check engine" light on?
Have you check for fuel pressure and a good spark when your car dies?