Driveability issue, no power while accelerating

[TUZ58]

Hello everybody;
I need some assistance diagnosing a problem. Car starts, and idles fine. Will drive ok, but when I try to accelerate car, no power! Boost
pressure will rise but it stays at same speed, and if you use accelerator
softly it will go, but as soon as you press down, nothing. It's a stock
86 GN no mods. Earlier this year I replaced the ignition module, and coilpack.
I have 38 PSI static fuel pressure at rail, and 14 volts at alternator at idle.
I re-set IAC and TPS. TPS reading .43 volts and 4.6 volts WOT with key
on not running. Replaced fuel filter and new plugs and wires. I do not have
a scan tool to monitor engine while running, but no major problems so far.
No malfunction codes and ECM has a stock burned chip from Turbo-Tweak.
It had a Hypertech chip which I placed in a ECM I purchased at a reputable
salvage yard. I swithed out ECM's and no difference. I'm running out of
ideas and any suggestion will be GREATLY appreciated! Also I have boost
lines hooked up correctly with restriction in T hose going to the compressor
housing unit.

 

[Just a Six??]

Welcome! Are you 100% sure you have no major vacuum leaks? Almost sounds like your wastegate rod is stuck & your not building boost? Maybe the puck in the downpipe is seized up?
Also, not that it pertains to your problem really but arent Erics chips usually set to 43 lbs line off pressure? Again, dont believe thats causing your problem. Good Luck!

 

[Sleeper-6]

You say you're building boost, How much can you get? Are the RPMs Climbing too? If so and there is no increase in road speed It sounds like a transmission problem.

 

[TUZ58]

Hello;
Thanks for answering my post. I did check for vacum leaks both visually and Isprayed throttle body cleaner around all hose inlet and outlets and couldn't find anything. Boost pressure on gauge will go up to 12 PSI when accelerating but car will not increase is speed at all and RPM's stay the same.
When you let off of it you can hear that sputtering? sound of trapped air being released like when you get into the boost and let off it quickly.
Also when I ordered chip on website I indicated it was for stock car.
I put old Hypertech chip that was in car when I bought it in a ECM I got at
a salvage yard and switched ECM's out but no difference. Hey, whats the best way to check that stock wastegate to see if it's operating properly?
Once again THANKS!

 

[maxcom]

have a similar problem but my rpms increase with almost no boost showing (stock gauges)

 

[Just a Six??]

Hello;
Thanks for answering my post. I did check for vacum leaks both visually and Isprayed throttle body cleaner around all hose inlet and outlets and couldn't find anything. Boost pressure on gauge will go up to 12 PSI when accelerating but car will not increase is speed at all and RPM's stay the same.
When you let off of it you can hear that sputtering? sound of trapped air being released like when you get into the boost and let off it quickly.
Also when I ordered chip on website I indicated it was for stock car.
I put old Hypertech chip that was in car when I bought it in a ECM I got at
a salvage yard and switched ECM's out but no difference. Hey, whats the best way to check that stock wastegate to see if it's operating properly?
Once again THANKS!

To check the stock wastegate, first unhook the clip from actuator. Then do a couple ways. Add some air to the hose to Actuator & see if it moves with air & pull on it with pliers etc to see how well it moves with hand pressure. Just to be sure its working correctly & not leaking at the seal.
Then for the puck! Actuator unhooked, grab it where the clip holds puck at downpipe with your fingers & it should slide up-down freely about 1/4 turn. From 6-9 kinda movement. If not, Puck is stuck!! Then take off Downpipe & free it up. Note where the carbon circle is with a picture & see where/why its sticking.
This may not be your problem at all, but at least take the 5 mins to check it all out first with DP on so you can move forward from here.
Cheers!

 

[BlackBandit]

First off you need a scan tool. I know you're probably thinking it's stock so it shouldn't matter but it does. You can kill an engine just as effectively with 12 pounds of boost as you can with 25 pounds of boost. Off hand I would suspect you're encountering large amounts of detonation. This would explain why it falls on it's face at WOT but goes under lighter throttle. Try turning up your FP to the specified 43 psi line off. Also, if you're using the stock boost gauge it's probably wrong so I would find another way to check boost pressure. If you have adequate FP then 12 psi should be safe assuming you're using premium fuel and you don't have a stuck injector or something. If I was you I'd try and find a local Buick guy that will hook up their scanmaster and see what's going on. Good luck with your problem. james

 

[XLR8]

If the fuel pump is stock replace it NOW with a good unit and hot-wire it. Without a scan tool you have no idea why it's not making power.

 

[TUZ58]

Hello;
Thanks for the additional posts. I had planned on some upgrades plus a scan tool, but car was running great until this, and when funds become available will make purchases. In the meantime will pursue some of the suggestions on above posts. Is there any way that I can increase my FP with stock FPR, and stock fuel delivery system? Also, any way to tell if I have a bad injector?

 

[jhanson1750]

TUZ58 Where are you located? We might be able to hook you up with a local that can help. Jon Hanson

 

[Just a Six??]

Hello;
Thanks for the additional posts. I had planned on some upgrades plus a scan tool, but car was running great until this, and when funds become available will make purchases. In the meantime will pursue some of the suggestions on above posts. Is there any way that I can increase my FP with stock FPR, and stock fuel delivery system? Also, any way to tell if I have a bad injector?

There is an old trick but definately not the safest way when an adjustable is $100 They used to Crush the regulator with Vice grips etc & that raises pressure a few lbs but again, I wouldnt do it!

 

[TUZ58]

Hey Guys;
Once again thanks for your replies. I'm located in Meadville PA.

 

[86george]

No power

Hello everybody;
I need some assistance diagnosing a problem. Car starts, and idles fine. Will drive ok, but when I try to accelerate car, no power! Boost
pressure will rise but it stays at same speed, and if you use accelerator
softly it will go, but as soon as you press down, nothing. It's a stock
86 GN no mods. Earlier this year I replaced the ignition module, and coilpack.
I have 38 PSI static fuel pressure at rail, and 14 volts at alternator at idle.
I re-set IAC and TPS. TPS reading .43 volts and 4.6 volts WOT with key
on not running. Replaced fuel filter and new plugs and wires. I do not have
a scan tool to monitor engine while running, but no major problems so far.
No malfunction codes and ECM has a stock burned chip from Turbo-Tweak.
It had a Hypertech chip which I placed in a ECM I purchased at a reputable
salvage yard. I swithed out ECM's and no difference. I'm running out of
ideas and any suggestion will be GREATLY appreciated! Also I have boost
lines hooked up correctly with restriction in T hose going to the compressor
housing unit.

Your injectors may need cleaned.I've had good luck useing Seafoam cleaner.If you still have a cat convert you should check that.A nearly plugged cat will cause your problem. Good luck.

 

[87turbot-type]

I would check for a stuck open egr valve. Would explain the vacuum leak you can't find and when you drive at low throttle it doesn't get confused with the extra air until you open the throttle.

Try tapping the top of the valve with a hammer. Your IAC would probably be closed to compinsate for it at idle.

Just a shot.

Brandon!

 

[TUZ58]

Hello;
Come to think of it, right before I had this problem I almost ran out of
gas. Anyone know where I can get the fuel injector cleaning kit that has the aerosol can and hose that screws into the port on fuel rail? Thanks!

 

[Just a Six??]

Get a new filter first if you almost ran out of gas. Could just be full of Crud!!

 

[TUZ58]

I put new fuel filter on and also dropped tank and cleaned that out last week! Also took pulsator off and put piece of fuel hose on from pump
to outlet tube.

 

[bmackinnon]

Hello;
Come to think of it, right before I had this problem I almost ran out of
gas.

May have put the final bullet in the old fuel pump that was barely holding on..... You need to tape that fp gage to the windshield and go for a drive... make sure the fuel pressure is RISING with boost, not falling from a dying pump. If fp goes down as you try to gas it up..... it's dead..... That's what happened to my stock pump.... would make the pressure at idle, then start falling as I tried to accelerate...

 

[87turbot-type]

Did you check the EGR valve yet?

 

[TUZ58]

Hello;
I checked the EGR valve by pushing up on diaphram from
underneath whle at idle, and motor choked and when I let go
it went back to a smooth idle, so I think it's ok. Going to
check that fuel pressure while driving car under boost
next. Thanks!