89 Chevy Van 20 w/ 5.7l / 42k orig ml
Starting to get the infamous "check engine light" when going uphills. On downgrades the light goes off. Generally engine performance is "less than stellar". Plus fuel consumption has gone way up.
It started happening after filling up w/ 87 for the first time in 6 months. Wuz using 89 and 92 octane. Since then, I've been putting in 89 and 92 once again, but it has not helped. Fuel injectors clogged possibly?
I guess it could be simply ignition problems. -> plugs/wires/cap ?
I come from the old school and I am not familiar w/ fuel injection systems.
NO oil loss/water temp normal/no excessive exhaust...if this helps.
Have others out there w/ GM 5.7l had this problem?
Your advice is appreciated..