I have a 98 Blazer 4x4 automatic that stalls only when coming to a stop. It has a reman jasper motor that has 49 K miles but the truck and most components have 180 K miles. Everthing works good and the motor runs Solid.But I have a problem with it stalling. It only stalls when coming to a stop. The rpm'S just drop out and it cuts off. It does this every single time I stop. Ive checked alternator and battery wireing.I was just wondering if anybody had the same problem or what it might take to fix it.

 

Have you ever cleaned the throttle body or EGR valve? If not, that is where I would start. Especially if these components were swapped over onto the replacement motor.

 

check your fuel filter and do a fuel pressure test, my 98 started to stall out when stopping or shifting from park into drive after it had been started, ended up having a terrible fuel filter, even with changing it in the last year, and a weak fuel pump which was replaced and solved the problem

 

I tried cleaning throttle body and egr vavle. I replaced the fuel filter.But, I dont have a pressure gauge so I couldn't check the fuel pressure. It is still stalling out when I stop. I was just wondering if someone had any more suggestion's on what I could check or replace. Because I checked reciept's and found the fuel pump was replaced less than 25 k miles ago.

 

Sounds like it could be a bad IAC.

 

I just checked IAC and TPS on throttle body. The IAC checked 60-70 ohmsacross both terminals A+B C+D. And the TPS operated smooth. Was .62 volts at idle position and 4.5 at wide open,smooth all the way across. Can anybody come up with anything else. I have a repair manual But it isn't much help in trouble shooting. Like I said earlier, The motor is running Smooth andStrong, But every single time I come to a stop the motor stalls out. The faster I come to a stop the Quicker it will stall. If I drive like a grandma and start breaking WAAAAYYYY before a stoplight , Sometimes it will not stall, But 98% of the time it will, Just as im about to stop. Alway's stalls in between 10-0 mph as Im coming to a stop. Any help or suggestions will be greatly appreciated.

 

Perhaps its a manual and your not stepping on the clutch when you brake??? Totally kidding... hope you appreciate sarcasm.

Anyway, I had a similar problem with a totally different vehicle; although there were some idling issues as well. Anyway, with her car it was a vacuum leak. The leak was letting too much air in, so the properly functioning IAC closed way down to account for the leak. Then when you suddenly slow the engine (by braking fast) the IAC doesn't respond fast enough, and the closed down IAC in combination with the low RPM can suffocate the engine (despite the vacuum leak). Vacuum leaks can do weird things. Also, isthe Service Engine Soon light on? Have you tried reading the codes?

Anyway, thought I'd add that I also have a Jasper Engine, and I'm actually from Jasper where they are made and know the president of the company, its a pretty cool company. I've never had problems with the engine.

 

I have found a temp. solution and I dont know if it is going to hold true. But this morning I thought "well when i bought it a couple weeks ago I test drove it and drove 1.5 hrs. back home", It never stalled. But now it stalls every time I stop. What is the difference. When I bought it there was 3/4 a tank of fuel. Afterwe got home I would put in $10.00 in gas, Then run low andput in another $10.00 . So I never had more than a 1/2 a tank(mostly less). So this morning I filled the tank, and I have not had it stall. Now I don't know this will hold up. I haven't driven it more than 30min. whatdo you think it couldbefuel pressure regulator maybe ? I let yall know if the fill up job does the trick. Im still going to fix it but at least I want be stalling in the meantime (Hopefully) .

 

I've had kinda the same problem with the rpms just dropping off. is the SES comming on and if so what is the code. mine did it for a few days before the light came on and it was saying both o2 sensors reading lean. problem i had was there was a small crack in the intake manifold causeing the motor to get way to much air. fixed that and everything ran fine. just a thought.

 

Believe it or not, check your battery connections!

Mine was doing the exact same thing(if I didn't hit neutral, and keep my foot in it, it would die when stopping). All I did was clean the terminals, and it fixed it. All I can figure, is that it wasn't keeping the voltage constant enough, for the brain, when it dropped to a low idle. Cheap fix for me!!!