Swapped a 5.8 in place of the 5.0 that was originally in this truck.
Has HO cam, long tubes and maf conversion from FMS.

I made sure firing order was right on dizzy. ill triple check again. I haven't found vac leaks and only codes I have are 81,82,84,85 makes sense because the emissions stuff isn't plugged in. I am running a cw31 EEC and yes I am for sure getting 2 digit codes. Thought i'd get 3 but whatever lol. Truck starts and runs idle surges and then will stall. I currently don't have an o2 sensor on it because It wouldn't fit between the trans and the header. Maybe I need to loosen it up and thread in o2 and try again and maybe this issue clear up. I believe it did run better when I first plugged in the ecu but once it hit operating temp is when these issues came about. Now it does it when cold or at operating temp. When I try and give it throttle it bogs down. I did verify TPS voltage and that was good. Maybe running way rich? I should probably check timing also. Maybe even need to clean IAC. Any thoughts on what else I should check. FPR?


Here is a vid

 

No O2 sensor means instant open loop.

I'd address this first.

 

Word, that's what I was thinking. Ill probably see if I can get that o2 in tomorrow or something reset ECU and go from there.

 

whats your fuel pressure? what are the cam specs? what injectors are you running? the engine will be in open loop on startup no matter what, so the fact that the o2 isn't there shouldn't keep it from idling.


stranger things have happened though...if its initial startup, and a lot of changes have been made in airflow, cam timing, etc, the default tune in the computer from what it used to control may not be accurate enough to keep it running right, I.e. will require closed loop time to make adjustments, or a tune will be required.

 

Not sure what fuel psi is. Ill check that. Cam is a stock 5.0 mustang HO cam. I did get the o2 wire up. Still having this issue. So I will check & clean IAC too.

I did notice my belt was squealing so Ill fix that issue maybe the fluctuating voltage is causing some issue at the ECU too. I did just measure 12.0 volts at the battery.

 

even with a failed alternator, should still run fine w/ 12v on the battery. now if you have a bad connection somewhere, bad ground, that can cause all sorts of funky issues and will not charge properly. check voltage output of the alternator...


besides that I'm curious to see fuel pressure


also what'd you pull the MAF out of? did you run the maf before the swap?

 

If your not getting proper, 12+ voltage, sensors will not be very accurate, giving erroneous info to the PCM. Try and get the alternator repaired or replace, charge battery and then start troubleshooting. Proper battery voltage and good solid, steady voltage output is 1st step. If not, then your pulling hair and throwing parts at the problem.

 

It shouldn't be failed as I JUST bought it. Before the belt started slipping I was seeing 13.56v I was sure I hooked up my grounds including the orange ground too. Ran out of time today so I didn't get to test fuel psi.

Also the maf is a stock mustang maf that came with the m-9000-t51 kit from FMS I wonder if it is no good?
That's kind of what I was thinking. Reason why I have belt slipping too is because I tried running a shorter belt...because no smog pump. But the shorter belt doesn't seem to be working right. Im probably going to get that delete pulley or gut the pump and run it.

 

Unplug the maf and see if anything changes, if you think it might be bad.

I'm running a short belt with no air pump and no slip. Might need to go shorter. I highly doubt low voltage is your problem considering you read 12v (fully charged) battery and have an intermittent alternator. 9-10v, then it might be an issue.

 

ill try that. I am running a 968 (stock is 102) belt but I also have the later accessory brackets as this as an f4te block in it now. So it has a side tensioner and the upper idler.

I believe the 96 maf trucks with cali emissions have a factory smog pump bypass installed. Im going to research that too. Or just buy the proform one.

 

That combo should run fine on that C3W1 computer( I have one of those too) but you need to put an airbox or something on the end of that MAF meter to stabilize airflow through the sensor.. even a foot long length of ducting will help.

 

Word dude. I have the factory maf ducting sitting around. I haven't seen if it'll fit.


Also I am going to set my idle according to this.

1990 Ford Bronco FMS MAF Installation Instructions picture | SuperMotors.net

 

Unless you changes the TPS this won't be necessary.

 

oh well damn. lol I guess onward to more figuring stuff out.

 

Nice to have Ole Conanski around, "eh?"