A while back I built the following:
Stock re-ring, reman crank, file fit rings, new oil pump...etc
World Windsor JR heads
Stud mount roller rockers
New lifters
New Double Roller timing chain
TFS-51402000 cam
A9l mass air conversion stock mass air sensor
T5 conversion.
ARP Head bolts
Cheapie Professional Products Typhoon Intake
Clayed the PVC, checked all the tolerances, file fit the piston rings for perfect clearance. The bottom end runs smooth and runs quiet.
New FPR and filter.
But I cannot get the thing to idle below 1100. It runs strong in higher RPM bands. Sometimes when its cooler outside, it wants to idle around 1900....very annoying :mad::mad::mad::mad: It will also try to idle high after a good WOT run. Turning the car off and back on will have it settle down to 1100 again.
Codes deal with the emissions stuff that is not hooked up.
Things I have done:
1. I have checked a million times for vac leaks, I am certain there are none.
2. Removed the IAC, cleaned Installed.
3. Removed IAC disassembled, cleaned, reinstalled.
4. Swapped IAC with one from another engine
5. Installed new IAC
6. Set TPS voltage.
7. Swapped TPS with another.
8. Installed TPS
9. Reset the Idle per multiple methods about 1 million times.
10. Readjusted the valves (I am about to try this again using my dial gauge).
11. Checked IAC Voltage
If I disconnect the IAC, and adjust the idle, the computer will compensate the timing to kick up the idle and wont go below 1000. If I pull the spout it will let me adjust it down to around 900. Any lower and it starts to surge or tries to stall. Once I plug the spout and the IAC back in it shoots back up to 1200 or so.
Is there anything I have missed?
EGR is attached but is ornamental (no vacuum source) but it seals good and would probably work if hooked up.
I will pull codes again tonight to see if there is anything new as my girlfriend has been daily driving the car lately. Maybe I will get a vid. I am starting to think about pulling a whole harness from the Junkyard.
Thanks.
Codes?
Put up what codes you have. Also have you done a cylinder balance test after running codes?
Could the timing be off? I am having a similar problem but not as extreme as yours.
How about the screw in the TB.Or binding in the throttle linkage. also what injectors and maf,are they matched?
Just throwing some things out there. "Possible bad vac. leak." Lower intake spray it down running, see if it changes rpm.
that seems to be the #1 problem when the IAC and TPS check out fine
I'm thinking more a vac leak, check it it sure sounds like it.
Specially the ends of the intake, A vac leak will cause a idle issue. Not sure how you put the lower intake on, everybody has there own way, I know I have mine and never had a leak.
I will check again for air leaks. Ive spayed around with brake clean before to no avail. No binding in the throttle linkage...nice and smooth.
I did try this however. I removed the screws for the tps and let it hang loose. Then i started it and set the base idle. I was able to get the base down into the 800 range without surge. I notched the tps holes and reinstalled it at exactly .89 v. Started it and it idles pretty reliable at 1000ish.
I will check timing but i think i had it set at about 14.
Stock maf and 19#ers.
I'm still leaning vac. small hose disconnected. Cam timed right? like I said throwing it out there. It's not hard to overlook the simple things.
Man these things can be so frustrating. Hope you figure it out soon!
Codes...
Followed by a vacuum test....
FWIW -- Swap out that MAF and injectors for a matched set using 24 pounders for that combo and use at least a 155 LPH pump.....
WIth a stock HO MAF and 19's at stock pressure I'll bet you'll see a code that says the adaptive fuel strategy lean limit has been reached......
Welcome to the world of performance cams and stock electronics, mine has had some surge on cold start from day one, but has never increased in idle...
What is the TPS voltage???(.999 I bet) If so reduce it to around .9 and no higher to see if it helps with the hanging idle, do so after setting the base idle... I use around 900-950 RPM in gear, but mine is AOD...
EDIT
Paul may well have something, I didn't realize you had a stock MAF on it... But thinking back, I don't remember having any more/less of a idle problem when I ran the stock meter and 19lb inj...
Just a shot in the dark but how are your grounds? Bad grounds will cause some strange problems.
I actually got the lean code with my combo and 19s. Since I've switched to 24s and a 73mm C&L MAF I've no longer had that code.
I will try pulling codes tomorrow. I take the CEL out so I can pass inspection (no dash lights). I am also getting some bucking. I am starting to think its this cheap after market intake. Maybe leaking at the heads.
I've been wondering about this. The car should have some real umph but it seems like there could be more. As this is my outgoing project, can I grab a junkyard set of injectors and MAF from a Mark VIII? Or do I have to shell out big bucks for a pro-m and the like.
Injectors yes but MAF no. Factory Ford MAFs are not calibrated to an injector. The EEC has the injector size in its programing. Aftermarket MAFs are "calibrated" to trick the computer to run bigger injectors with the 19lb program.
Ok, heres the dirt.
I pulled codes koeo:
51 - ECT sensor signal is greater than the Self-Test maximum of 4.6 volts.
22 - MAP/BP sensor out of self test range.
53 - TPS circuit above maximum 4.5 volts.
54 - ACT sensor signal is greater than the Self-Test maximum of 4.6 volts.
35 - PFE or EVP circuit above the maximum limit of 4.81 volts.
85 - Canister Purge Solenoid circuit failure
95 - Fuel pump secondary circuit failure. The EEC senses infinite resistance to ground from the fuel pump on the Fuel Pump Monitor circuit.
I ignore 95, I did not hook up the fuel pump relay signal during the swap to mass air.
Hmm those sensors share the sig return line. So I added a ground (just a wire clipped on to the ground going to the TPS)
Disconnected the neg cable for 5 minutes to clear the codes.
Re-ran KOEO:
31 - PFE or EVP circuit below minimum voltage of 0.24 volts.
85 - Canister Purge Solenoid circuit failure
95 - Fuel pump secondary circuit failure. The EEC senses infinite resistance to ground from the fuel pump on the Fuel Pump Monitor circuit.
Weird, ok.
Ran KOER:
41 - HEGO sensor circuit indicates system lean (right side).
31 - PFE or EVP circuit below minimum voltage of 0.24 volts.
The car seems to be running rich (sooty exhaust, floods on startup occasionally, dark plugs). Do you suppose my left 02 is bad? They are $40 at autozone. I might try to pick up a few at the junkyard instead. I can't imagine its running lean.
85 perplexes me too because all the emissions is hooked up with good vac lines.
It starts better with the extra ground I added but it still wants to idle really high. If I remove it, it drops down to a nice 900 rpm idle. I'm pretty tired of these gremlins. I have to DD the car too until I get my girlfriends truck fixed (shes driving my normal DD). At 10 mpg its killing me. I will try to shoot the wires this weekend and find out why the sig retn is open.
-Z
You could try swapping the O2 sensors side to side and see if the lean code follows the O2 sensor.
Also are the O2 sensor wires are on the correct side?
Thats a good idea. I think they are, but I did swap the engine and harness when I rebuilt the engine. I just transfered it to the new engine I built.
Also, I had to take the ground wire off on the way to work. It was popping, coughing, and couldn't accelerate at all. Removed the wire and it dropped to a nice idle and drove just fine. Still way down on power.
Clear codes again, unplug the o2 harness and pull the spout out. Restart it and see if your still running rich.
What will unplugging the O2s and the spout do?
It will stop the adaptive strategy by the computer. You will have to advance your timing, but it will tell you for sure if its the o2's or not. If the computer never gets any information from the 02's, it will just go to a stock table and guess on what it needs for fuel.
I know very little about EFI. But have you tryed a new MAP sensor? The MAP has a vacuum port on it it could have some sort of internal vacuum leak. A bad MAP sensor could cause it to run rich could'nt it?
Yea, I swapped in a different MAP. They both act the same.
Also its converted to MAF so its a ambient pressure transducer so it has no vac line now.
Does your injector harness plug into the main EEC harness like the Mustangs do with the two ten-pin connectors at the back of the intakes? I was having all kinds of issues with my Coupe and it turned out to be these connectors.
I also had a problem with the car due to the O2 sensor harness coming unplugged from the main EEC harness.
I would keep the MAF and injectors you have in the car until you sort out the electrical issues. No sense in chasing a possible lean condition with the car is running pig rich.
Darren
It does, and I've gone through the salt n' pepper shakers a couple times now. I agree, I am going to work out the codes before I start swapping parts. I have an adjustable FPR that is waiting until I can get this problem ironed out.
The good news is I'm back driving my Jetta. Fixed the GFs finder (pathfinder) this weekend so she can drive that. So this fix just went from "OMFG Fix it NOW" to "Fix it so I can sell it"
Why would you sell it over such a small issue? Isn't this the car with a new motor and custom cam, or am I thinking of someone else?
Planning to go back to school. It was a $300 junker I rescued and messed around with. I'm also selling my Jetta and my house soon with any luck. I've got the mustang and I've decided it's the car that will go into storage at my parents cabin. I might just part it out and keep the engine and trans (t5) for the stang. Not sure yet. It's fun to drive, but between my girlfriend and myself, I have 5 cars to feed/insure. Just too many.
Yeah, you might be better off with less cars. You might be better off fixing the stang. But either way, good luck and let us know how it goes.