2.8 stalls under load?

[bimdub]

ok I have a 1988 Buick Regal 2.8, this vehicle starts and runs with a slight miss, when under load it has no power and eventually will stall, this problem has rapidly gotten worse.

ran the codes and got 34...replaced the Map and Mass airflow meter just to be safe, the car idles better but now it stalls more and is not giving trouble codes.

I tested the fuel pressure after putting a new filter in, and its nearly rock solid at 40psi it spikes a bit right before it stalls to around 45 psi.

I can visually see the occasional miss with the timing light hooked up to the 1/4 coil pack, so I suspect that coil may have trouble.

also when the engine dies....I can still see the timing light flashing which is what is bothering me the most, I would have liked to suspect the ICM or even the CPS at this point but its still firing the coils.

I am at a loss....and running out of time on this one it is like someone just shut the key off in the car when it stalls, I suspect the fuel injection pulse is getting shut off.....could this still be related to the ICM going out?

[60dgrzbelow0]

Pull the plugs and read them... Greasy, black and gummy? Bad Valves and/or Bad Rings ...or even both (mileage on the car?) A big drop in compression will cause an early stall. A compression test first without a few drops of oil in each cylinder and then with...should reveal the bad rings side of this issue if there is a big difference between the dry/wet tests.. But if the plugs innards are a nice, "Fried Chicken Brown and Tan" ...then check for a bad, loose (or off) plug wire(s) at the plugs and at the coil plug connections. The car is 21 years old... in Dog Years...that means its very long over due for something to break down. As for the PCM issues... remove all the sensor connectors, spritz them inside with some CRC electrical contact cleaner and then re-plug them all back in... you'd be surprised how much corrosion can build up on the connectors inside those plastic housings after a few decades of wear and tear and make them fail or mis-read. Change the PCV valve just for drill too while you under the hood....and change the fuel filter, too.... Its always a GOKWIT! situation as the car had been on the road since 1988... (God Only Knows What's In There!)

[bimdub]

ok maybe I need to give more information, the car has a much newer engine (re manufactured a couple years ago) and new plugs and wires, this is a friends car that has been maintained immaculately until it was parked a year ago....it has good compression and vacuum, new fuel filter was done right before I did the pressure test, I honestly think it is not signaling the injectors to fire, it tries to run if I give it fuel, I know there is 40 psi at the rail and it seems to be getting spark, going back to electrical connections, I have removed the coils and the ICM and cleaned them as well as reconnected them and it made no difference, I also checked the CPS which seems to be good, where is the ECM located? is it behind the glovebox ala GM typical?

[robertisaar]

being a W-body, it shouldn't be... all W's got weatherproof ECMs... i would bet its in the same place as a 90GP: on the passenger side of the engine bay underneath a big plastic cover.

[60dgrzbelow0]

ok maybe I need to give more information, the car has a much newer engine (re manufactured a couple years ago) and new plugs and wires, this is a friends car that has been maintained immaculately until it was parked a year ago....it has good compression and vacuum, new fuel filter was done right before I did the pressure test, I honestly think it is not signaling the injectors to fire, it tries to run if I give it fuel, I know there is 40 psi at the rail and it seems to be getting spark, going back to electrical connections, I have removed the coils and the ICM and cleaned them as well as reconnected them and it made no difference, I also checked the CPS which seems to be good, where is the ECM located? is it behind the glovebox ala GM typical?

Any chance at all that somewhere on the engine/manifold there is a cut/broken/loose vacuum hose? Also...these Noid Lights work effectively to test the harness and the PCM/ECM signals on the car...and will very quickly help your diagnosis of what you suspect the problem to be. (See Link Below...the lower portion of the listing has all the dope on how they are used...)

http://cgi.ebay.com/Auto-Noid-Lite-Electronic-Fuel-Injection-Test-Light-Set_W0QQitemZ290343478332QQcmdZViewItemQQptZMeters_Testers_Probes?hash=item4399d1e43c

[bimdub]

yeah I have been looking for a set of these, I almost made my own to verify the lack of injection pulse. I still suspect something is amiss with the ICM and its not sending the signal to the ECM. personally, the car is in really good shape and its well worth saving, I may not own a 60 degree GM six at this time but have in the past and they have always served very well....you guys are very helpful.

[bimdub]

ok noids have been purchased, I used to be a diagnostic technician, but have moved on and no longer have access to all the "tools of the trade" I really miss the four gas and scope I used to use daily, as well as the service manuals.

[robertisaar]

i can help somewhat with the service manual parts....

[60dgrzbelow0]

ok noids have been purchased, I used to be a diagnostic technician, but have moved on and no longer have access to all the "tools of the trade" I really miss the four gas and scope I used to use daily, as well as the service manuals.

It won't take long now for you to nail down the problem and put that car to rights again. There are some very talented, capable and interesting members here in this cool place that collectively...must have ten thousand man-years of experience with all the versions of the 60* and 90* power plants...and most of them will do everything they can to help everyone else out when the odd thing stumps the best of us...

--== Welcome to www.60degreev6.com ==--

[60dgrzbelow0]

ok maybe I need to give more information, the car has a much newer engine (re manufactured a couple years ago) and new plugs and wires, this is a friends car that has been maintained immaculately until it was parked a year ago...

If the car sat a year... without so much as one turn-over, then the gasoline sitting dormant in the tank definitely went stale and sour as well as in the fuel lines and especially...whatever residual fuel was left in the EFIs that could clog up the super-fine screens on the inlet side or bake on in the hot engine after shutdown so as to gunk up the tiny "spinerette"-like nozzles in them.

When you first cranked it up...did you notice whether or not there was an overwhelming "stale gas" smell around the vehicle?. If so...the very best "In the Tank" fuel system cleaner is... hands down...Chevron "Techron"... a few treatments with some small bottles of this stuff in several tanks of gas might just do the trick ...and wake up any "Sleepy" EFIs...

[bimdub]

i can help somewhat with the service manual parts....

do you have them in PDF?

I got a PDF one for my Honda S2000......great tool!

[robertisaar]

i haz the alldata for 82-02 GM cars...

and some foreign stuff too...

[bimdub]

sounds expensive

[robertisaar]

sounds expensive

*cough* WAS *cough* expensive...













.....for someone.

[bimdub]

ok...bought the noid lights....connected the little bugger to the number one injector...fired the engine up....let it warm up.....raised the rpms with the fule pressure gauge still connected as well as the timing light (for spark verification) my timing light is triggerless so it remains on.

as I raised the rpms the flashes from the timing light get faster.....the flashes from the noid get brighter and faster, the fuel pressure remains at a solid 40 psi, then at about 2500 rpms the noid stops flashing, the timing light continues to flash as the engine winds down and the fuel pressure stays at 45 psi.

something is apparently cutting the injectors off at this point, even if you let off the throttle it still dies so. so I guess I need to check the ECM and see if its getting the signal from the ICM at this point?