90 Lumina 3.1 - Cutting off while driving or accelerating

[ibbobud]

My 3.1 Lumina has started doing the following:

- engine will start and imediately die
- Sometimes start but ruff idle then die
- Stop running while accelrating and driving (not miss, completely looses power)
- and now it just sputters and dies when starting

It has a new fuel pump, and is geting good fuel pressure. it hasnt done it much till today and seems to do it must when geting on the throttle. Feels like all cylendars loose power for about 2 to 2 sec and gets worse when you apply throttle then all the sudden its fine and runs great.

im thinking ignition module. Suggested appreciated, its on the side of the road.

[Schurkey]

Originally Posted by ibbobud

My 3.1 Lumina has started doing the following:

- engine will start and imediately die
- Sometimes start but ruff idle then die
- Stop running while accelrating and driving (not miss, completely looses power)
- and now it just sputters and dies when starting

It has a new fuel pump, and is geting good fuel pressure. it hasnt done it much till today and seems to do it must when geting on the throttle. Feels like all cylendars loose power for about 2 to 2 sec and gets worse when you apply throttle then all the sudden its fine and runs great.

im thinking ignition module. Suggested appreciated, its on the side of the road.

Burnable fuel/air mixture
Spark at the right time
Compression
Unrestricted exhaust

You figure out which of the four things listed that it doesn't have; and you'll figure out why it doesn't run right. I wouldn't expect compression or exhaust to be an issue since this appears to be somewhat intermittent.

You say it has fuel pressure. Have you tested the spark?


http://www.amazon.com/KD-Tools-2756-...=31ORN63IXRW6M

There are other styles of spark tester that work just as well, but these are the kind I use.

[ibbobud]

I went to where I parked the car this morning and same result. Trysa to start sputters and dies. I used my timing lifght to check for spark and got good steady flashing from the light on all the plugs I could get to when cranking. I also attempted to spray some carb cleaner into the throttle body and still did the same thing... How strange unless carb cleaner won't make the engine run. I'm going to attempt it again with starting fluid tomarrow. Anoyher note I've got good fuel pressure.

[maxwedge]

Flashing light does not confirm strong spark, may not be enough to fire the engine. Injector pulse should also be checked especially if starting fluid works.

[mcmalloy]

check the wiring at the back of the engine , see if its melted to the exhust

[ibbobud]

Today i got some starting fluid and sprayed it into the intake. The motor will run (spark knocking and not smooth) on the ether. It has good fuel pressure. As stated before, it tries to start but just sputters and quits as soon as you stop cranking it. If you take the injector fuses out it dont even sputter, im about positive ive got a bad injector or ecm. Here is a list of things ive tested.

- Fuel pressure is good
- Spark at all 6 plugs (tested using timing light)
- Engine will run on starting fluid
- Wiggled all the wires going to fuel injectors i could (no change)
- Pecked on the ECM (no change)

Next steps im assuming is to pull off the upper intake and check the resistance of the injectors and replace a bad one if found. If none is found then check wiring going from injectors to ecm, and then finally ecm itsself.

Any comments or helpful corrections to this plan will be appreciated.

Thanks!

[maxwedge]

Try tapping the ecm with a small hammer handle, see what happens could be the ecm, they were not reliable when new.

[ibbobud]

Originally Posted by maxwedge

Try tapping the ecm with a small hammer handle, see what happens could be the ecm, they were not reliable when new.

I allready wacked on it with a screwdriver handle allready, should i do it harder? haha

[ibbobud]

Can you test the entire circuit at the ecm harness?

If there is 3 injectors on each bank, and each injector is post to be 12 ohms, then i should be seing about 36k to 40k ohms for the entire bank correct? I dont want to have to crack open this intake if i dont have to... Blah.

- Remove injector plug from ecm
- Identify injector bank 1 and 2 wiring
- Connect the positive lead of meter to the fuse for injector bank 1
- Connect negative lead to the bank 1 signal wire at ecm plug and test resistance (12 ohms x 3 resistors = 36 ohms + wiring resistance)
- Same procedure for Bank 2

I would assume with a +/-1% tolerance and with the wiring also causing resistance that i would be shooting for a 40 ohm resistance at the ecm connector. Anything Drasticaly higher or lower would mean pulling the upper intake. If they are in spec, then replace the ecm.

My theory work?

[ibbobud]

Where heres my update...

After taking a look at the ecm and realizing it was the origional ecm i desided i would change it first due to its easy access. After replacing the ecm with a cardone remanufatctured unit from oreily's ($75.00) i attemped to start it. At first it seemd like it wouldnt start like before then all the sudden it caught after some hickups it started to idle fine. The drive home seemed non eventful and i also noticed i was no longer geting a code 32 (egr) code that i was allways geting even after replacing the egr valve. The idle seems better also.

So now the question is...

Was it really a bad ecm or is the new ecm just handling out of spec injectors better than the old ecm?

Should i still take the upper intake off and check the resistance on the injectors?

Im taking it on a extended test drive tomorrow.

[ibbobud]

It's Back!

Its starting to do the same thing again.. just not as bad. Im assuming its still bad injector(s) and the new ecm just tolerated it better.

Recuring syptoms:

- Starts and lopes like its not geting anough fuel or too much air and dies... touching the trottle is instant death. after about 3 attempts it settles down and idles.
- Randomly looses power (almost like cuting the switch off) while accelerating.

[ibbobud]

Originally Posted by khung88876

Try testing Crank shaft postion sensor, and cam sensor, temp sensor, clean idle control sensor. As stated before do compression check, beleave it or not run gallon E85 through it works well cleaning entire fuel system, just dont leave it sitting in ur fuel system, RUN IT OUT asap.

- Allready been through 2 tanks of gas
- Engine still gets spark when this behavior happens and will run on starting fluid
- Cleaned idle control valve and throttle body (no idle issues when it does deside to run normal)
- When it runs right it has plenty of power and zoom zoom's no need to test compression

can the temp sensor cause these issues? even if it was bad i would think it would just pull a code and put computer into limp mode at the lease or make it run rich or lean.

egr passage is clogged so its time for a plenum cleaning. when its off all the injector resistances are geting checked to elimate that issue.

[ibbobud]

I pulled my upper intake off this morning to test the injectors.

Injector Resistance Test: (min. allowable resistance 12ohms)
Cyl. 1 - 12.7
Cyl. 2 - 11.4
Cyl. 3 - 8.5
Cyl. 4 - 6.3
Cyl. 5 - 12.7 (new injector replaced last year)
Cyl. 6 - 12.7

I have ordered 5 new injectors to match the newone on cyl. 5 so i will have a complete new set and not have to worry about it.

I will have (2) good injectors for sell cheap if anyone needs any!

I have also soaked my upper intake in degreaser and cleaned the egr passage.

Below are pics with the upper intake off and the upper intake after soaking in degreaser.

[ibbobud]

Project complete!

Replaced All the injectors, cleaned the plenum and egr passages, gaskets, and pvc valve and hose.

Car now runs great with no codes and does not shut down anymore!