1998 Chevrolet Blazer Q&A
1998 Chevrolet Blazer Question: Why does my Blazer stall in hot weather only?
I have a 98 Blazer that has plagued me for months on end. I installed a new fuel pump, dist cap, rotor, wires, plugs, crank sensor, coil, ignition module, swapped the MAP, cleaned the MAF, new filters, checked just about everything and on hot sunny days especially when stuck in traffic, it stalls and won't restart until it cools. I can drive it all night,and on cool days and it will run like a top!!! I have not replaced the 02's yet, nor the crank sensor. I did break off the coolant temp sensor and JB welded it back on and the gauge reads fine. When it stalls it acts like it's too lean and starves out. I have gotten a few P0171's and another lean condition on the 02's, but I'm ready to rip off the hood so it will let the heat out of the hood compartment!!! PLS Help! - 00Mickx
Same model year Blazer, mines a 4 DR 2WD. I am experiencing the same issues. I replaced bank one O2 sensors one and two, Ignition wiring, plugs, fuel filter, and flushed the hell out of my cooling system. You may want to take a look at the front two O2's. I had a check engine light the first time I stalled, it read low voltage on them (lean mix of course) but they were really fouled because of the bad mixture that they was hitting them. (one was bulging a bit) It almost seems to me that the heat kills the relays but if that were the case the horn and everything else relay dependent would fail as well. Like you said, I just want to rip the effin hood off of it. I am going to take the tank down tomorrow and look at the wiring harness. My theory to this is if the connectors are corroded at all they will put extra resistance on the relay and it will stick. This probably occurs more in the HOT weather because electrical components (relays / wires) are more susceptible to failure. I have heard from many people that the wiring harness on these models are notorious for problems. Another theory that I may look into if the harness is in decent shape is to have the VCM read on a full diagnostic and reset. I often wonder after getting those lean codes and such if things are actually reset properly with other engine management. Disconnecting the negative battery terminal may clear the light, but what is the VCM REALLY doing? I will post again tomorrow with my find. - AultJF
Well im not sure if your fuel pump was the problem. It might of been bad. Who knows. But what i do know weather doesn't effect P.S.I. the pump puts out. Also you're not supposed to check the P.S.I when you shut off your vehicle because some cars will drop the line pressure to 0 after shutting down. run the engine and check pressure. Now what it sounds like to me is that You have an idle problem. Clean the throttle body, clean the idle port inside the throttle body. Run the engine until normal operating tempreture 195-210 degree then check the idle with a scan tool. should be between 700-900 rpm. I would take it to 800 rpm. Note: check your IAC valve. Make sure its not rusted over or siezed. - Visitor
pull the battery tray under it there is a black box with a 75 amp fuse clean the fuse ends that bolt on then check the frame and body grounds ad more if you need to but run them direct to the battery rust will kill electrical connections and i did change my cam sensor but i would wager on electrical issues. ok this did not help it is the bcm or the pass lock i have tried everything and i am gonna replace it with a ford f150 gm built this to fail you cuase they think we will buy a new car from them well i choose ford or dodge. - burnt1973