I am kind of at a point where I am not sure what to do next. Which isn't surprising because I don't know diddly about this stuff, yet.

Here's my setup and then my problem. Engine is a half bridge port, (not my 1st choice but that's what the car came with) recently rebuilt. Has 550 primaries and 850 secondaries bored to 1300 cc/min. Fuel pressure at idle or cranking is 36 p.s.i. Am running an open throttle body right now so I can get to the air bleed screw if necessary.

Last night I put the PFC in, set the primaries to -0.04 lag, secondaries to 0.20 lag, turned off sequential, and O2 feedback. Air bleed was open probably 3 or 4 turns and the vertical idle screw was also open maybe 3 turns after contact with the linkage. This is what it took to make it somewhat idle on a stock ECU. Started the car and it idled at about 3000 r.p.m. for awhile. I screwed the vertical screw up to slow the idle down, it would then hunt between 800 rpm and 2000. During all this time the AFR was about 13.5. What I didn't know was the brake booster vacuum line was off so I guess I had a big vacuum leak.

Saw that this morning, connected it and thought I would try to have the PFC learn the idle. So I started over with the air bleed, closed it down and opened it a turn, same with the vertical screw. Tried to start the car - it ran poorly a little bit (but the AFR was still around 13.5 to 14.0, stumbled and died. Can't get it to start or even sound like it wants to. Tried opening the air bleed and the vertical screw back up, but no help. Pulled one of the leading plugs and it was dry.

Can you guys give me some direction on what to do next?

Thanks,

Jeff

 

de flood

 

So if it flooded what to do I need to do to make sure it doesn't happen again. But the plug I pulled was not wet.

 

if you push the car and pop the clutch does it run?

for the idle... do you have your ISC valve installed? is the TPS in spec? is your thermowax/fast idle installed or properly eliminated? get the AFR's into the 12's for now.

 

Thank you for the reply. The car is on jack stands right now so I can't push start it. However, it was starting right up on the stock ECU, although it was running extremely rich. Started right up yesterday on the PowerFC but I was running it with the brake booster vacuum hose off. Put the hose on this morning and it wouldn't start. Does that indicate anything?

I have put the TPS in spec. Don't have an ISC. That and all of the emissions stuff was removed by the previous owner. When I was running on the stock ECU last week (just idling) the fast idle was responding best I could tell. Can you point me to directions on setting it up, or tell me how to eliminate it for now?

So do you think it is running too rich or too lean? I was thinking of fiddling with the Cranking Fuel Injection time. Would that be the place to start? Decrease the times by 2 to 4 ms? Are heavily ported engines (half bridge) typically too rich or too lean on the PFC base map?

 

You shouldn't have to mess with the cranking ms. You can fine tune it later, but thats not the issue. Bridge ports usually need a higher idle speed for a smooth idle. Most likely it is flooded, but check for spark on all wires. Run through the deflood procedure and get some fresh plugs if need be. Also without the ics the pfc wont do an idle learn. If you have a datalogit set all your idles speeds to 0 and run manual idle control. Starting these cars is pretty basic and doesn't require an extremely precise mixture, the pfc base map with correct injector layout and sizing is enough to get any type of port running. Set your idle to 12.5 to 13 afr once u get running. Its odd that the plug isnt wet, you might make sure the injectors are firing also.

 

with a half bridgeport the car is going to make a lot less vacuum in the idle area and that will require a lot of retuning. after setting your idle speeds to zero you will probably have to add more air with the screws on the TB. I'd also give it more timing in whatever cells it's idling. depending on what your idle rpm ends up being, I'd start with anywhere from 16 to 20 degrees leading (might need more than that) and maybe 3 split. Or you can also try negative split.

 

I appreciate the answers I have been getting. Wasn't sure what to expect with this engine and the PFC. Here is what I am going to try.

1. Will pull all 4 plugs, the fuel relay and de-flood. Tried it by removing the relay and just cranking with the accelerator down for a minute but maybe that wasn't enough. This will give me a chance to check all of the plugs for fouling. I have a new set I can put in if need be but didn't want to foul them if I wasn't getting this fixed.

2. I am wondering if it might be a primary injector. I don't smell gas at the injectors and I replaced the orings on the primarys but maybe they are leaking anyway. When I started it last week on the OEM ECU it ran so rich it would burn your eyes. When I first started it on the PFC (with a large vacuum leak) it idled at 3000. If the TPS was telling it to inject fuel as if it was idling and the extra air brought it to good AFRs maybe there was extra fuel because of a leak.

Any other way to tell if the injectors are working properly?

Do I need to find an ISC and put that on?

Thanks,

Jeff

 

Do you have the O2FB switched off, it should be if you do not have the air pump on and working normally. Being a HBP, I really doubt you have the air pump on the engine.

The ISC is needed for automatic idle control, if you do not have it, set the 3 idle speeds to 0.

You also need to set the 3 idle cutoff speeds at leaste 200 rpm higher than your idle. For now, set them to 2000 rpm.

 

Check your map sensor line, even with the porting and mods it seems odd that the stock ecu would be running THAT rich on stock primaries. Although without a cat these cars can smell pretty gasey anyway.

 

Thank you for the reply. Was able to de-flood it this evening and get it to run. However, it constantly varied it's idle speed between say 1200 rpm and 1600 or 1800 rpm. Up and down continuously. Injector duty went from 0 to 20% constantly. AFR readout would go from 13 to LEAN and back. Any idea what this might be?

I am not sure I have everything else in working order yet. I am wondering if I might have a leaky injector or leaky FPR. Fuel pressure drained down to 0 from 36 psi in an hour or two. Will start checking those kinds of things next. I'll try to start it tomorrow but if it is flooded again I guess I'll need to pull the UIM and fuel rails and see if they are leaking.

O2 feedback is set to OFF

I only have the Commander - no Datalogit. Will all at 500 be OK?

Is this accessible through the Commander?

I am in an area where rotaries and PFC tuners are not too prevalent. So I really appreciate all of your help.

Jeff

 

It's probably the pfc hunting for an idle by adjusting the timing back and forth. This is because the idle speeds are set to 500 not zero. It can never idle at what it's set to without the ics. You cant set it lower without the datalogit.Also make sure the tps is in range, that no sensors are highlighted in sensor check, and that the pim voltage is lowering once the car is started. You really need the datalogit it will help you in so many ways.

 

if idle IG control is enabled (like stock), the timing is going to go all over the place in this case. It wasn't designed to run without the ISC valve. If idle IG control is turnedd but idle speeds are not set to 0, idle timing will be fixed at -5 -20 (or a little higher depending how high the RPM gets). Either way the timing is going to be way off for a half bridge with no ISC.

the car ran super rich on the stock ECU because the vacuum signal is so much weaker. The ECU thinks the engine is under load.

 

So it sounds like I can't fix this unless I install an ISC or buy a Datalogit so that I can set my idle speeds to 0. Is that correct?

I have been reading all of the threads I can find on this, it sounds like not having an ISC and setting idle manually is doable, some say even preferable. May never idle well because it is a HBP but at least it shouldn't constantly change speed. Is that correct?

I appreciate that explanation. I was convinced I had a leaky injector (and I still might of course) but this does explain the rich idle.

Thank you and Chuck and Brent for taking your time to help me understand this.

 

A weak vacuum signal is going to cause the idle to lope to a degree. that's unavoidable. You can certainly smooth it out some, but I think most half bridges idle over 1000rpm and will fluctuate more than a street port. It's probably not worth putting the ISC back on. You need so much idle air through TB adjustment that it's almost pointless.

if you thought you were going to get away without buying a Datalogit, just throw that idea out the window. Even if you pay a tuner to tune the car he's not going to be there every second to help you with all the little driveability quirks that will inevitably come up.

if you run the PFC basemap on a street ported engine you will even see a rich idle. The car idles in different cells on the fuel map. A lot of driveability stuff gets messed up... how would you expect the MAP/Speed density Ford 5.0 engines to idle with a big cam on a stock ecu?

 

I was finding last night though that I could turn the air bleed screw in all the way and then back out about a half turn and it still seemed to run OK (or as OK as it could). Does that seem reasonable or would you expect to see the air bleed out 3 or 4 turns?

No I was always expecting to have to buy one. I was just hoping to get the car to a point with the Commander where I could take it around the block. Owned it a year now and haven't driven it.

So tonight I was going to start next by decreasing the fuel map by maybe 10% in the idle cells. I was thinking Rows 1 thru 8 x Columns 1, 2 and maybe 3. Does that sound like a good idea?

 

It sounds like your idle afrs are about right. You said it was going from 13 to lean back and forth, the reason it's going to lean is because the surging is making the ecu think needs to cut the injectors. The computer is trying to adjust several parameters to get the idle where you set it. Some people have had luck lowering all points to 500 to prevent the surging others not. You might even try setting the idle numbers closer to where its surging. Try setting them to 1300 and adjust your idle speed to 1300 if you can. Make sure the fuel cut numbers are a few hundred rpm higher. I "think" they are accessed in the commander but not certain. I use mine mainly as a gauge.

You should set the AFR's to about 12.5-13 and the goal is for them to hold steady. If it's already too lean then it's just going to run worse by taking fuel out. It might be too your map needs adjustments in the surrounding cells around idle. Another benefit to having a datalogit is you can post your map for us to look at.

 

The fuel cut settings are accessible in the Commander. I like the idea of setting the idle speeds to 1300 then adjusting everything for that. I'd do a fuel cut speed of 2000 rpm per Chuck's suggestion.

it depends on so many things such as throttle plate opening angle (which is affected by the fast idle system and the throttle plate screw it sounds like you've been adjusting). There's a wide range of acceptable TB configurations, just make sure that everything else in the system is working with it properly. Your TPS should be adjusted to spec for example.

 

Tried some of the things you guys suggested. I wish I could post a map but since I can't yet here are the Inj settings I messed with tonight:

N01 N02 N03
P01 110 110 115
P02 110 110 115
P03 110 110 109
P04 110 110 100
P05 110 110 092
P06 110 110 087
P07 110 110 092
P08 110 110 095

Idle A 890
Idle E 950
Idle A 1050

I am a little short of what I can do in the Commander for each setting. It won't go to 1300.

It stopped surging. Idle is sitting steady on about 1100 rpm. Moves between cells N03/P06 and N03/P07.

Air bleed is 1/2 to 1 turn out.

AFRs are holding at 12.4 to 12.6

Still has some black smoke but not as much as before.

One thing I failed to mention, I am at 6700 ft above sea level.

What is this fuel cut thing you mentioned?

Thanks for your help,

Jeff