Help with engine stalling problem on 95 Suburban.

[Chris B.]

I'm looking at buying a 1995 Suburban with the pre vortec 350. It has 200,000 miles on it and aside for oil leaks it is in good shape and runs well for the most part and the price is right. One problem that has me stumped is if I'm driving under 40 mph and slam on the brakes everything is fine but if I'm over 40 and slam on the brakes the engine dies or stalls and I have to put in back in to park and restart.
I was testing the brakes to see how well the truck stopped and found this problem. I have no idea what might cause this or how to fix it. Any ideas?

 

[HTSS_TR]

How much fuel in the tank ? It is possible that when you brake hard at higher speed with near empty fuel tank, the fuel pump was stave of fuel and the engine died.

 

[Chris B.]

It was almost empty, in the red. Hmmmmm? Someone told me the torque conveter migh not be working, how does that work? I'm no mechanic and can only do basic stuff. What would be worst case senerio and how much would it cost to fix it? I'm only paying $1,400 for it and the body and interior are in great shape so I would not mind putting in a couple thousand to fix her up. Thanks!

 

[Herz]

any other drivability issues other than the one mentioned?

 

[motorguy222]

The torque convertor could cause this and if so,it is working but not quite the way it should.GM has a locking convertor that locks up around 40 mph,it feels like an extra gear when it kicks in.This makes a direct link to the engine.

The convertors are locked by a solenoid and the solenoid will many times get stuck and when it does,it can cause the engine to stall out if it stays locked.

The solenoid usually isnt very expensive but you will have to get it put in by a mechanic,that may cost a bit but should not be very high.

You may be able to tell if it is the solenoid.Get up to about 50 mph and let it slow down without using the brakes.When you get to around 10 mph,give it gas and if it feels like it is lugging really bad,it is most likely the solenoid.

 

[Mokanic]

Fuel pressure or the lack thereof is the #1 cause of drivability issues with the TBI 350. The regulator on top of the TBI unit as well as the pump both give funky running issues.9-12psi pressure is what you should have.

 

[motorguy222]

It could be a fuel issue but the way he describes what happens,it really sounds like it is a solenoid.

 

[ronrackley]

If there is a tachometer on the dashboard, a very simple check is to get up to about 45 MPH on a straight and level stretch of highway where it is safe to be doing this and tap the brake pedal lightly with your left foot while keeping constant pressure on the accelerator pedal with your right foot. You should see an abrupt jump of something like 200 RPM when the solenoid unlocks the torque converter - which is supposed to happen as soon as the brake pedal is pressed.

If it is a problem with the torque converter not unlocking, it is almost certainly the solenoid. It is about a $50 - $75 part, but the cost of replacing it depends on what it takes to get to it. I don't believe the Suburban requires dropping the transmission like some cars that cost thousand$ to fix.

 

[Mokanic]

Just knock it out of gear above the speed it gives trouble and if it still stalls, you know it's not transmission related.

 

[Chris B.]

Thanks guys. No other problems were noticed. I wish I could drive it again to answer some of your questions but I don't have access to it. It is in the next town over. The prices is only $1400 and it seems solid so I may just buy it and expect to install a new transmission for $1900. I think it would be worth putting a few thousand in it and driving it for a while.

$1400 sound good to you guys? All the other 1995 Suburbans were $2500+

 

[motorguy222]

The price does not really sound bad if it is in good shape.If the solenoid is bad,you dont need a transmission unless there is something else wrong.The solenoid is only to lock up the torque convertor.Some GM's are bad for this.

If you are thinking about getting it,take it for a drive one more time and try the suggestions here,if it is the convertor,that may be why the owner is getting rid of it,they may think that the trans is going out.

I am not sure but I dont think that the trans has to be removed to change the solenoid on this.

 

[Chris B.]

Never mind! The seller decided he wants to keep it. Looks like the price was to good to be true. Most 3/4 ton Suburbans are selling for $2,500-3,500 in this area.....oh well. At least I don't have to come up with the money to fix it up and deal with fixing the problems.

 

[Herz]

sorry to hear that.