'87 Vandura, Stalls under load - The 1947 - Present Chevrolet & GMC Truck Message Board Network

damemorder · 08-23-2004, 12:35 AM

We've got an '87 GMC Vandura Conversion Van, It's been sitting for about two years with no prep. Our '83 half ton just lost four bearings and froze so We pulled out the van to use it 'til the truck is back on the road. It took about 5 minutes worth of cranking to get the van to start. Now it idles well enough and will rev in in Nuetral, But under load, like driving up the 12-13% grade to back out of the driveway, It stalls. It feels like it's barely running, and sounds almost as if it has an aggressive camshaft installed.

A little about the van.
Exhaust rusted off after muffler, Cat so clogged it blew the plug out.
Fuel filter just changed, Has good gas in it now.
got new cap, rotor, plugs, and wires just before it was parked.
PVC port in the carb is jam packed with something...

What do you guys think needs done to make this van drive for a few more years?

Russell · 08-23-2004, 01:37 AM

To me, it sounds like you are running a bit lean, exactly how my truck was / is, my problem is a big vac leak in the intake gaskets, which I am too lazy to change out right now, lol

See if the van picks up speed and runs smoothly if you close the choke plate...

damemorder · 08-23-2004, 02:05 AM

I think it's TBI, and I don't see a choke so uhh....

Russell · 08-23-2004, 02:21 AM

Ah, that'd do it, lol

Try taking the air cleaner off and sticking your hand over the throttle body opening, don't starve it right out, but enough to restrict air flow a bit, and see if it picks up any RPMs.

MylilBowTie · 08-23-2004, 06:37 AM

PCV has sludged up oil or carbon, Catalytic convertor is clogged up? Its not going to run right with convertor not letting the exhaust breath especially when the engine is loaded.

What did it run like before? I for me I seem to forget some of the little annoying things if I haven't driven that vehicle in a really long time.

damemorder · 08-23-2004, 12:08 PM

Just pulled off the throttle body, I'm suprised the thing ran at all. I see my TPS and IAC sensors, the injectors are full of crap and the vacuum ports are full of carbon. Sent my dad over to autozone to grab a rebuild kit and some carb cleaner, should be back soon.

Do you guys know the specs for these sensors? In my Bonneville that has a TPS that looks exactly the same it goes from .45v at idle to ~4.5v at WOT, Am I safe to assume these should be close? I can't get the IAC to move at all, You guys know if that's normal for this engine? I would assume I should be able to overpower the return spring in it....

Russell · 08-23-2004, 12:39 PM

Thats the same TPS voltages that my TPI's TPS puts out too, the IAC would be different between my TPI and your TBI though... I suggest checking www.chevythunder.com they might have what you need to know.

damemorder · 08-23-2004, 07:22 PM

M'kay, TB rebuilt. Although the inside of the TB was filty the inside of the intake manifold was very clean...

It's almost like the ECM is searching over too wide a range of fuel curves to start the engine. It's flooded twice and leans out easily, but will not run.

Am I correct to assume the ECM does not control the engine during startup until 400rpm have been sustained? If so, it's not even getting to where the ECM should kick in...

My dad says the cat isn't a problem as the plug is blown out dumping straight to atmosphere....

damemorder · 08-25-2004, 10:09 PM

Fixed. The fuel pump was dying a slow death and finally got to where it couldn't support the engine. It would only shoot fuel 3ft into the air, The new pump shoots over 13ft into the air.

cliffsta · 08-25-2004, 11:10 PM

lol good test

08-23-2004, 12:35 AM	#1
damemorder Registered User Join Date: Feb 2004 Location: Texarkana, Tx Posts: 21	'87 Vandura, Stalls under load We've got an '87 GMC Vandura Conversion Van, It's been sitting for about two years with no prep. Our '83 half ton just lost four bearings and froze so We pulled out the van to use it 'til the truck is back on the road. It took about 5 minutes worth of cranking to get the van to start. Now it idles well enough and will rev in in Nuetral, But under load, like driving up the 12-13% grade to back out of the driveway, It stalls. It feels like it's barely running, and sounds almost as if it has an aggressive camshaft installed. A little about the van. Exhaust rusted off after muffler, Cat so clogged it blew the plug out. Fuel filter just changed, Has good gas in it now. got new cap, rotor, plugs, and wires just before it was parked. PVC port in the carb is jam packed with something... What do you guys think needs done to make this van drive for a few more years? __________________ 1983 Chevette \| 1993 Bonneville \| 1992 G20

08-23-2004, 01:37 AM	#2
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	To me, it sounds like you are running a bit lean, exactly how my truck was / is, my problem is a big vac leak in the intake gaskets, which I am too lazy to change out right now, lol See if the van picks up speed and runs smoothly if you close the choke plate... __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

08-23-2004, 02:05 AM	#3
damemorder Registered User Join Date: Feb 2004 Location: Texarkana, Tx Posts: 21	I think it's TBI, and I don't see a choke so uhh.... __________________ 1983 Chevette \| 1993 Bonneville \| 1992 G20

08-23-2004, 02:21 AM	#4
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Ah, that'd do it, lol Try taking the air cleaner off and sticking your hand over the throttle body opening, don't starve it right out, but enough to restrict air flow a bit, and see if it picks up any RPMs. __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

08-23-2004, 06:37 AM	#5
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	PCV has sludged up oil or carbon, Catalytic convertor is clogged up? Its not going to run right with convertor not letting the exhaust breath especially when the engine is loaded. What did it run like before? I for me I seem to forget some of the little annoying things if I haven't driven that vehicle in a really long time. __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI

08-23-2004, 12:08 PM	#6
damemorder Registered User Join Date: Feb 2004 Location: Texarkana, Tx Posts: 21	Just pulled off the throttle body, I'm suprised the thing ran at all. I see my TPS and IAC sensors, the injectors are full of crap and the vacuum ports are full of carbon. Sent my dad over to autozone to grab a rebuild kit and some carb cleaner, should be back soon. Do you guys know the specs for these sensors? In my Bonneville that has a TPS that looks exactly the same it goes from .45v at idle to ~4.5v at WOT, Am I safe to assume these should be close? I can't get the IAC to move at all, You guys know if that's normal for this engine? I would assume I should be able to overpower the return spring in it.... __________________ 1983 Chevette \| 1993 Bonneville \| 1992 G20

08-23-2004, 12:39 PM	#7
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Thats the same TPS voltages that my TPI's TPS puts out too, the IAC would be different between my TPI and your TBI though... I suggest checking www.chevythunder.com they might have what you need to know. __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

08-23-2004, 07:22 PM	#8
damemorder Registered User Join Date: Feb 2004 Location: Texarkana, Tx Posts: 21	M'kay, TB rebuilt. Although the inside of the TB was filty the inside of the intake manifold was very clean... It's almost like the ECM is searching over too wide a range of fuel curves to start the engine. It's flooded twice and leans out easily, but will not run. Am I correct to assume the ECM does not control the engine during startup until 400rpm have been sustained? If so, it's not even getting to where the ECM should kick in... My dad says the cat isn't a problem as the plug is blown out dumping straight to atmosphere.... __________________ 1983 Chevette \| 1993 Bonneville \| 1992 G20

08-25-2004, 10:09 PM	#9
damemorder Registered User Join Date: Feb 2004 Location: Texarkana, Tx Posts: 21	Fixed. The fuel pump was dying a slow death and finally got to where it couldn't support the engine. It would only shoot fuel 3ft into the air, The new pump shoots over 13ft into the air. __________________ 1983 Chevette \| 1993 Bonneville \| 1992 G20

08-25-2004, 11:10 PM	#10
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	lol good test __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord



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