JBeachstang11

Went on a longer drive today, hottest day in the history of the world too. Car' didn't overheat either even with some moderate driving. Looking to swap the ghetto fan setup for a contour or mark 8 like I used on my ram. Nice fans. Already wired in a controller but doubt it would run the mark 8 amperage.

Anyhow still need to check the tps voltage, but it idles rough and surges. Set the timing today at 13 and lowered the idle screw so it was around 800 or about on the BE2012 readout.

BE won't give me MPH, Fuel Pressure or ECT readings which I'd like, especially for datalogging.

Only real issue today was some mid rpm sputter under moderate to heavy acceleration. I thought maybe I gapped my plugs too wide but they are set at .051" and it calls for .054" so that's fine.

Once I got home I realized my base timing was good but I have a A9P computer (prev owner) in my original 5spd car. All that is good except the timing curve is more aggressive with the P so my 14 deg is huge even off idle 1000rpm.

ECU 1000 rpm 1800 rpm 2600 rpm 3500 rpm 5000+ rpm
A9L 8 ° 18.5 ° 22.5 ° 22 ° 26 °
A9P 21.25 ° 21.25 ° 27.25 ° 26 ° 30.75 °
X3Z cobra 8° 18.5 ° 22.5 ° 22 ° 25 °




Should I back off the timing to around 8 or so do to this? Kinda makes sense now that it was sputtering under accel if my timing was way advanced no?

It has 93 oct in it but engine is only 9.0:1 static.

mjr46

14 base shouldn't cause any spuddering, I'd look elsewhere for the issue, I run 19 base on a 347 with no issue

JBeachstang11

Just curious what comp you are running?

Also started to check tps volts and right away the green to black was .48 so going to open the holes for adjustment to put it within the range for idle then check the wot and how the voltage increase looks as the blade opens.

90nSSMD

That tps voltage could be the idle gremlin. I have mine set to .97.

If I recall correctly the ford specs for the tps voltage are between .8 and 1.12, although most people swear by .96-.98. .97 has mine idling perfect at 900 with an e cam. Best of luck on diagnosing that surge issue!

JBeachstang11

Thank you! Just seems this could also be affecting my sputter at hard acceleration since all the ignition is new besides the coil which is fairly new, and this would affect wot readings and open loop mode.

90nSSMD

Didn't know you had a miss under load. TPS would be the first thing I would look at definitely, especially with your current voltage being under .5! If the problem isn't solved by changing the voltage, and the TPS isn't new, try replacing it. Try setting voltage between .95-.99 and tweak from there if need be.

Another thing you can do is pull off the IAB and check for carbon deposits. Sometimes those things can get clogged/stuck and cause idle issues as well.

mjr46

around 10.5 compression I have......also setting tps to .98 is a myth if you know how the ecm thinks per EEC IV GFUB DOC. ANYWHERE from .7 to 1.00 vdc is acceptable, do a sweep of the tps and look for opens

JBeachstang11

Definitely, thank you for the advice.

I reset the TPS to read .95 idle and 4.00v at WOT and it reads smoothly all the way up to 4.00 as you open it.

I checked the IAC plugged in and unplugged, same surging and stalling out idle. Pulled it off to clean it and hello there is a block off plate.. I removed that, cleaned the iac and the mounting surface. Reinstalled and tried again.

Same result except with a nice whistle that goes up and down with the surge. It won't stay running unless I hold it above 1000.

Also the EGR is disabled in the A9P so anything on the egr plate would have no bearing unless there was a vacuum leak correct?

So the search continues.

JBeachstang11

Right, from what I understand it's a range to be in, and also getting your wot volts proper.


"around 10.5 compression I have......" - Sorry I meant what computer Are you running A9L, A9P, A3M? etc..

JBeachstang11

Replaced with new IAC and no real change, seems a little better but still stalls and won't idle.

Pulled codes eng off Key on and got..

15 rom test fail or power interrupt to memory
85 ecessive fuel pressure or flow, canister purge circuit

91 (not sure since eng was off?) Oxygen sensor problem, fuel pressure out of specified range or injectors out of balance

96 Fuel pump circuit

Oh goody...