Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
The only code is p0500 which is vss1. At first I thought this was the reason for the limited rpm. Then I took the unfiltered speed signal wire and ran it directly to ecm and on my scan tool have a speed signal. But still no rev past 3500. I verified it’s losing spark and not fuel by spraying carb clean in t-body. I can’t seem to find the problem, I’ve checked the igniter, put oem spark plugs, 2 crank sensors, cam signal looks as it should no matter the rpm as well as crank sensor, knock sensors pass the test, changed the coils and plug wires. Checked and rechecked and rechecked again the valve timing. Something is causing the ecm to limit the rpm it will not accelerate over 3500. All the power and grounds are at the ecm as they should be. Everyone says they have never seen a ecm go bad.
Please help as I’m completely at a loss. I can’t find any more ground to cover
- Does the car have normal power? If not, check for blockages in the exhaust (Clogged catalyst converter maybe)
- How are the MAF-readings?
- What are TPS-Sensor values? Does they go up to 100%?
- goes the throttle-body fully open when you push on the gas-pedal? (can you command it manually with your scan-tool)?
TPS reads as it should all the way through the sweep. Maf reads correct. Someone already cut the Cadillac convertible off it. I have a verus pro scan tool to work with.
