View Full Version : stalling when warmed up

01-18-2016, 10:37 PM
On Sat we decide to go wheeling and we couldn't get buddies 93 Blazer f\s out of the driveway. As soon it was warmed up it would stall. Did it several times and no go. So yesterday I went over and we replaced fuel filter. IT started right up and then after 5 min or so it stalls. So I got in started it up and watched tach. It idles nice then goes up about 200 rpm and then just stalls. I checked Idle speed sensor and it was extended and we cleaned it and pushed it back in and then installed it. Started right up and stepped on throttle a few times to reset it and still same prob. We thinking it may be a coolant sensor malfunction or throttle position sensor. Any idea? It idles fine till it warms up and then idle rises and then stalls. If you feather the gas you can drive 20 feet or more but keeps stalling. Buddy needs his truck to get out to faller-buncher and the his car just go stuck too many times today lol.

01-18-2016, 10:42 PM
tps or fuel pressure?

01-18-2016, 10:56 PM
That truck has a self diagnostic in it look up how to do it
Or just keep guessing
A faulty temp sensor will typically make it run rich when warm
Because it thinks it's still cold
Could be a ignition module failing
Could be fuel pump
The thing you call idle speed sensor is the iac idle air control
Throttling it bypasses that

01-19-2016, 07:23 AM
Thanks for the tips. I forgot too take code reader so will start with reading the codes first.

01-19-2016, 08:05 AM
FULL SIZE blazer ? TBI ?
My 91 HAD problem with fuel pressure regulator in throttle body - exhaust gases rotted out the spring in it. No checking fuel pressure between it and injectors

01-19-2016, 05:38 PM
My 93 blazer did the same thing replaced iac, egr, fuel filter, fuel pump , all air hoses, tps, pretty much all the sensors and cleaned fuel spider and still did that so I scraped it fuckin hate Blazers nothing but problems

01-20-2016, 08:50 AM
Fordtrailer that really sucks! Aspen, yah fullsize with tbi.

01-20-2016, 09:09 AM
Definately will scan it first. Forgot to mention egr vacuum line was disconnected when I first popped the hood. Hooked it back and same problem. I don't know if a disconnected vacuum egr would have led to stalling prob. Start with a scan.

01-20-2016, 10:54 AM
When its running-stick finger in egr and manually open -see if changes for egr prob.
took 2 years to diagnose broken spring in fuel pressure regulator-almost gave up! the engine gases are fed up to the air cleaner right where the fuel pressure regulator is and eats the metal on the spring-you cant tell till you take it apart and preloading the diaphram and spring to put back together is a beatch.
I got a tbi unit from a wrecker to try and voila- cant remember codes i got:confused0006:

01-20-2016, 05:20 PM
So Aspen just to confirm, you had same problem? It would stall during idle once engine warmed up? And once fuel regulator spring was replaced in solved problem?

01-22-2016, 07:30 AM
stalling - hunting rpms - fuel pressure was off so kept going into limp mode and finally system would say screw it.
replaced just about everything , had it in shops till i finally figured out what it was.try to look into tbi to see what injectors are doing when it dies-not good spray pattern or fuel shutting down

01-22-2016, 07:41 AM
do u have a mass air flow sensor?

03-28-2016, 08:26 AM
No MAF sensor on this year of TBI. A friend at 100 Mile Lordco told me about the paperclip test to diagnose check eng light. It was a code 34 and that was MAP sensor low voltage. So found a test using my DMM and sure enough voltage was low. As far as I know buddy took Blazer to Chwk this past wknd and no problems. He was pretty friggin happy he did not get it towed to a shop.