1990 Caprice Classic V8 5.0 305 TBI Stalling at idle
Asked by Bethany Feb 11, 2019 at 10:36 PM about the 1990 Chevrolet Caprice Classic Sedan RWD
Question type: Maintenance & Repair
Was having issues with hesitation and
acceleration, changed out the fuel
pump, relay, and filter as well as air
filter. This fixed the hesitation and
acceleration issue, but now she keeps
stalling. At first it was on the highway
twice. Now when I start her up, she
idles high, then low, then she sputters
and dies. Won't start again until a bit of
time has passed. Picture is a log of all
parts replaced and repairs done since
I've owned the vehicle. I'm hoping its
the IAC or Oxygen sensor and not a
loss of compression. Any ideas?
7 Answers
Check for vacuum leaks, get it hooked to a scanner to check the MAP sensor TPS and 02 sensor also check the EGR and PCV valves.
EGR and PCV have already been replaced. It doesn't support OB-II scanners, MAF sensor doesn't apply. Also, just changed out most of the vacuum hoses so I don't really think there's an issue there.
Hi there, I have a 1990 Caprice and I’m now having the same exact issue that you’ve described and it would be very helpful if you’d share what did it take to have it fixed!
Shit, there were so many things I ended up doing it's hard to tell which one did it. Throttle body desperately needed cleaning, MAP sensor vacuum line was deteriorated, IAC was stuck open, return fuel line clogged so it was flooding the engine after startup, fuse to the fuel pump relay and some wiring needed repair. I've since gotten a 94 Cheyenne with the same TBI system so I'm a lot more versed in these systems since I posted that. Can you tell me exactly what it's doing at startup? That may help me better try to diag it based on what you're experiencing.
When switched on, it just runs for few seconds and dies again, replaced all different kinds of sensors and cleaned the tbi but still having the same issue!
Yes but is it a slow/hard start? How does it idle before shutting off? Can you post a video?
After it runs high and low does is it couple of times then dies Couldn’t post a video, the website only allows photos
