1991 Chevy 1500
#1
1991 Chevy 1500
I've got a 1991 chevy silverado 1500 that'* got 1999 heads on it, and it'* throwing code 34 with is indicating high vacuum for the MAP Sensor, problem is I've changed the MAP Sensor twice, no air leaks anywhere, and I feel like I might have something to do with the lack of EGR maybe? 1991 Egnines had one and 1999'* did not, so i don't know if that'* part of it? All help is appreciated looking for a work around or a fix. Thanks.
#2
Senior Member
Did you do any testing? What does the scan tool show at KOEO? idle? 4000 rpm?
I have the factory info for it if you would like something.
I have the factory info for it if you would like something.
Last edited by carfixer007; 03-21-2023 at 08:52 AM.
#3
Have scanned it with KOEO, but idles around 1200, idle isnt rought or anything, but she'll die just idling, and ill lose power running down the road around 55-ish
#4
Senior Member
I was looking for numbers.
Did this start right after the heads were done?
Did this start right after the heads were done?
Last edited by carfixer007; 03-21-2023 at 11:29 AM.
#6
Senior Member
What is the MAP value with koeo?
#8
Senior Member
I'll need to get my info pc fired up and see what the value should be at your altitude. What is the altitude there?
#10
Senior Member
That reading is way to low which corresponds with the code set. Here'* the info on it.
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CathedralCub (03-23-2023)