lq4 swap wont rev over 2500rpm help please

[tlmoore2501]

Have you let it set and run to get up to temp.?Have you put it in gear and drove or attempted to Rev past 2500rpm (power brake)?

[Liltroy]

Originally Posted by tlmoore2501

Have you let it set and run to get up to temp.?Have you put it in gear and drove or attempted to Rev past 2500rpm (power brake)?

Yes and yes. Several times.

[Liltroy]

Ok does anyone know a test procedure for the pedal sensor? Also what should my MAF sensor be putting out? There has to be some way to check this stuff with a multimeter. Checked throttle body operation again last night and it is very smooth. No jerky movements. Tested to half throttle and full throttle several times with engine off and it responded correctly every time but still only 20% with engine running. Reset the ecu and it let me have 27.8% one time after I started the engine, then locked out at 20% again on the next rev. I shut it off, help pedal to the floor showing 99.6% and started the engine and it immediately snapped back to 20%!! Wtf is up with this thing!!!??? I've searched all over the Internet and nobody else has had this issue!!!!!

[Liltroy]

Think my ecu died��

[Liltroy]

So the last few times I used my scanner, every time I started the truck it would blank out the scanner screen. I had to plug it in with the truck already running to take live data readings. Yesterday when I started it I had to toggle the key on and off multiple times before the fuel pump finally kicked on. I chalked it up to oxidation on my fuses or something. Today I went to start it and same issue. I pulled out the multimeter and I'm getting power to fuse, power to relay from fuse and from ignition, but no power signal from ecu to kick the relay. I plugged in my scanner to the one port and it won't connect to the ecu. Can't help but wonder if this has been the problem all along....ecu was on its way out? I can hear the throttle body snap shut when I turn the key forward though.....isn't that controlled by the ecu as well?

[BR3W CITY]

The battery and charging system were verified good, right? At this point I'd figure we checked that....but there are certain systems that will function on 1.5, 5, and 10v...so they can "work" without getting the full 12-14v that they should be getting.

Otherwise, that ecu might be toasted somewhere inside.

[Liltroy]

yep I've got over 12 volts at battery. just boxed up the ecu to ship to aknovaman tomorrow to check out. truck is cursed I tell ya!

[aknovaman]

Its fixed. Harness and file in pcm were jacked up. Liltroy can post burnout pics.

[Liltroy]

the ultimate problem was I paid good money to the wrong person to do my tune and harness....at least thats the way I see it. Aknovaman got it all starightened out for me though. Thanks Anthony!!!!

[72MARIO]

I read all thru your build last night and noticed you were not happy with the harness when you got it back from the modification post #114

Glad to see you got it running !

[slotard]

Glad to hear you got it running, too bad it took 3mo longer than it should've.