GMC Safari stalls all the time

[maketracks]

I am having a major issue with a recent hand-me-down, it is the 1994 Safari rear drive minivan. I want to get this thing moving and in use but it stalls all the time and I am unsure why. It doesnt run so hot. Let me see if I can describe it, basically it stalls at every light and then will start right back up again. It doesnt overheat but it is a PITA to drive because everytime a full stop happens, if that full stop is not done gently and then popped into neutral to gas it, it dies and stalls out.

I am on the younger side, I am 20 however I want to try to fix this myself due to being broke. I fear the spark plugs on this due to the placement of the engine in that short front it has. There is also a hole in the air intake tube.

What do I do first? And what all could cause this?

 

[SuperDave456]

Spark Plugs, Wires, and selenoid pack/distributor cap replacement would be a good place to start.

I've seen something similar in a old Chevy Nova where it would stall out at every light in the morning due to a cracked distributor cap. Moisture would build up in there over night and cause issues in the morning.

How many miles does this beast have?

Oh yeah, and WELCOME to BITOG!

 

[eljefino]

The hole in the intake is a great place to start.

Also these things had issues with the fuel injection, needs exactly the right pressure and the MPFI/TBI "head" tends to go south.

Do safaris have a "doghouse" inside the passenger compartment to get at the engine?

 

[AlienBug]

If you give up on DIYing I'd give Bill at Autotown on Boston Ave a go at it. Done business with him for 30 years and he's the nicest guy you'll ever meet in the repair biz.

 

[threeputtpar]

Originally Posted By: eljefino
The hole in the intake is a great place to start.


This is where I'd start. It's probably running really lean with a leak in the intake, expecially if the leak is after the MAF.

Plugs and/or wires are also a good thing to do, but if the plugs look a light tan color and the gap is still good they can still be run. If you're really running lean like I suspect, the color of the plugs will be the same as a brand new plug, i.e. no color. A properly running engine's plugs should have some tan to brown color on the insulator and around the threaded base.

 

[jrustles]

Sounds like an EGR valve that's stuck open.

 

[maketracks]

Originally Posted By: SuperDave456
Spark Plugs, Wires, and selenoid pack/distributor cap replacement would be a good place to start.

I've seen something similar in a old Chevy Nova where it would stall out at every light in the morning due to a cracked distributor cap. Moisture would build up in there over night and cause issues in the morning.

How many miles does this beast have?

Oh yeah, and WELCOME to BITOG!


This beast has a wellridden 205,000 miles on her.

Lunch break so I will proof-read this as best I can.. I am a student so I can't post up here too much, but let me give an update:

- I ordered a replacement air intake assembly off of EBay. $50. Saves me a trip to the scrapyard, time is valuable.
- I cleaned out the throttle body with some Carb and Choke cleaner I got at Walmart
- I changed the oil, it has a remote oil filter and the oil filter oil looked disgusting, somebody never changed the oil.

What I am doing right now is doing some reading for when my parts come. I want to change the Big Three as they call it that is the big three battery wires. I found some nice 2-gauge wires for the black and red cables, but what I cannot figure out is how they branch off. It looks like the wires split, and one goes to the alternator, but then another goes somewhere else? I would like some tips as to removal of this, it appers to be driving with no alternator there is no change in voltage at the voltmeter, and it is side-post. Hate GM. I also ened to know the eyelet size, sinze I found good cabling on EBay by the foot, 2-gauge or 2 AWG, how many feet will I need?

I suspect low voltage, and the hole which will soon be replaced with a hose that has no hole, are prime suspects in stalling. Spark plugs, no fun.. have not yet looked.

EGR and IACV not yet checked; the Idle Air, if it is right there at the throttle body, I cleaned as best I could. Still think that vacuum leak is playing a part, I taped it up and it runs better but not quite perfect.

Scared of this car, I am doing what I can do. May get another and sell this somewhere.. Or keep it around to learn on it before I get sick of this buried engine. http://mrgreywolf38.hubpages.com/hub/Removing-the-Engine-from-a-1997-GMC-Safari

Any tips as to the wires upgrading maybe this weekend or next, this is a work in progress in my spare time, since I am replacing the alternator and servicing its charging system too and that may be a factor in what it is doing now, running bad due to low voltage and bad connections?

 

[eljefino]

Pick up a Harbor freight voltmeter and get volts while running and off. Should be 14.5 and 12.4 respectively.

Don't go chasing down wires when you have bigger problems.

IN fact I'd get a haynes book for this and read it cover to cover before tearing into things. If this is your first project car splurge and get the factory service manual off ebay... a year or two off even if the price is right. GM FSMs are great for getting an idea of how a general GM car works and in fact how to do general automotive repair.

 

[The_Eric]

Being a TBI engine, this shouldn't have a MAF sensor. The hole in the intake duct shouldn't affect the engine if it is on the inlet or dirty air side of the air filter.

What these things do have a problem with is the gasket under the TBI unit. It will suck in towards the throttle bores and create a vacuum leak. To check, spray the carb cleaner around the base of the TBI while the engine is running and see if you notice a change.

If, after that you still have issues, I'd suspect the IAC.

Also, a tune up is likely a good idea - plugs, wires, cap/rotor, air filter, fuel filter and PCV valve. Don't cheap out on the wires. I've seen several cheap sets come through that were "just installed a little bit ago" be bad enough that they were arcing out to various points through their UNDAMAGED insulation.

 

[Jarlaxle]

A 1994 Astro could have the old TBI engine or the new MPI engine. IIRC, 1993 was the first year and they were both used into 1995.

 

[mechanicx]

Since it idles in neutral and stalls in drive it could be possible the torque converter clutch solenoid is staying locked. Does it stall out at a stop sort of violently, or like a manual transmission would if the clutch was left engaged, after it is driven for a bit and gotten up to speed about 40 mph?

 

[mechtech2]

Vacuum leaks, EGR system. Also a filthy TB.
If it runs poorly when at speed, normal tune up parts as well.

 

[maketracks]

Originally Posted By: eljefino
Pick up a Harbor freight voltmeter and get volts while running and off. Should be 14.5 and 12.4 respectively.

Don't go chasing down wires when you have bigger problems.

IN fact I'd get a haynes book for this and read it cover to cover before tearing into things. If this is your first project car splurge and get the factory service manual off ebay... a year or two off even if the price is right. GM FSMs are great for getting an idea of how a general GM car works and in fact how to do general automotive repair.


This one?

Astro service manual

So, if I get that what will it tell me?

Presently thinking of everything it could be, from old plugs and wires to the EGR and the IACV etc. I have a new air filter housing on the way, one with no hole in that hose, for starters. It runs well but it could sure run better

The stalling at the light sounds strongly like a vacuum leak because I need to usually give it gas to start back up. Sometimes not but it sure idles weakly. I am afraid to come to a stop in it due to this, until we figure out why it is doing that!

 

[maketracks]

Also, my battery terminals. Are they 3/8" thread? They appear to measure 1/2" however I cannot find anything to hold them at 1/2", only 3/8" so are the battery eyelets negative and positive side-post 3/8" thread as I want to replace those cables, thanks

 

[The_Eric]

If it's a side post battery, then yes, they are 3/8-16 threaded.

 

[maketracks]

I also hear a "pop" noise when it is running, and a tick/sputtering noise at speed when I am driving it, occasionally. This seems to correspond with then the Service Engine Light comes on. I have a dongle that should let my scan tool fit the GM OBD1 port.

I have a new distributor cap and rotor on the way, and if someone can tell me what spark plug socket I will need I will attempt to get in there and pull the plugs, to replace with AC Delco. New hose is on the way if we suspect vacuum leak, I cleaned out the TB, have not yet found the EGR nor IACV, and perhaps it is bad timing. The spark plug wires, I was thinking a NAPA Belden set (they are pricey but I heard they have a warranty.) Is 7mm fine or should I spend more on thick wires?

I also bought 2 AWG 2 feet negative battery cable and 3ft positive, with 3/8" eyelets. Hoping to replace the battery cables that are on there now. I want it to stop STALLING at lights, it sometimes does and sometimes doesnt. I need to start using it not sitting here letting it run to figure out what is going on!

 

[maketracks]

I have also done this



Trying to see what is causing it to stall out, especially if I am hard on the brakes to a stop. Seems as though it could be vacuum, then I have to give it gas to start back up. I need it to cut that out.

 

[maketracks]

ATM, I have the sensor that came out of the bottom of the taped-up air intake hose clean out. The car still hesitates at lights, but seems to roar back to life in an idle before it stalls. Still stalls and smokes.

What should I do next?

 

[mattd]

have you retrieved any trouble codes? try tapping on EGR valve with small hammer and listen for any idle changes. Smoke the intake for vacuum leaks as well.

 

[maketracks]

OK, it is running without stalling now, but I do see a healthy amount of black/dark gray smoke. What is up with that?

I disconnected the sensor that plugs into the bottom of an elbow of sorts, that goes between the air intake hose and manifold. It is no longer up in the part that looks like a slinky