terryking7
Forum Newbie
Posts: 35
Loc: Brisbane, Australia
Reg: 03-17-09
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08-11-12 06:12 PM - Post#2258266
Hi All:
I have a funky problem with my FI setup that I need some collective wisdom on.
Firstly, my setup (everything is brand new and never been run in):
Twin turbo 350 Chev
TPI setup (high flow trottle body, intake, and plenum and Edelbrock runners)
57 lb (570cc) bosch injectors (8 ohm high impedence)
Haltec F10X ECU
Set up for batch fire not multipoint
MSD AL6 ignition, MSD dissy (advance locked out and timed at 28 degrees), MSD Boost timing master currently set at zero degrees retard/1 psi.
Fuel pressure is a constant 43psi
2 bar map sensor
Max boost 15 psi
The problem is this:
The car idles smooth but needs to be rich (AFR around 11) for it to idle ok. Any leaner than this and it starts to pop in the exhaust (like a back fire).
At idle, the left bank EGT is reading around 70 degrees hotter than the right (350 vs 280).
Under light load (which I only have done briefly) the EGT difference between the 2 banks is much greater at 200 degrees (600 vs 400)
The car is not missing, that is all 8 cylinders are firing, and I have brand new spark plugs in it.
I cannot map the fuel under load as the popping becomes worse (along with the EGT problem) and I do not want to push it at this early stage.
I have tapped the injectors with a wrench while idling in an attempt to free one up IF it was sticking. No change.
Any suggestions on what I might do next. I'm thinking of pulling the fuel rail off to get to the injectors so I can have them tested, but before I dive in blindly I was hoping to get some opinions.
Cheers,
Terry
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Danny Cabral
Member
Posts: 3164
Loc: Ellington, CT
Reg: 11-03-04
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08-11-12 07:06 PM - Post#2258280
In response to terryking7
1) Use a test light (or noid light) to verify all injectors are pulsing.
2) Use a timing light to verify all plugs are igniting.
3) Use a temp gun (or damp towel) to verify all cylinders are firing.
4) Check the compression on all cylinders.
5) Check for exhaust leaks on both banks.
6) Try swapping injectors bank-to-bank, does problem follow?
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, A/C, Lentech Strip Terminator AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim-over steering, 4" lift, 35" tires |
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mike beck
Contributor
Posts: 218
Reg: 05-20-10
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08-11-12 07:43 PM - Post#2258287
In response to terryking7
You're going to hate that intake, but since that is what you're using right now let;s see if we can help.
Do you have the runners on the correct sides? They are not the same though they look identical. You could have a vacuum leak if they are reversed.
Is this a Corvette intake? They have an externally fed EGR system on the 'Vettes. Are you using EGR? If not, do you have the correct block-off plates and gaskets on them?
What heads are you using?
It is fine to lockout the timing, but you need to remove timing per psi, you seemed to state you are not removing any. Doesn't matter at idle/part throttle, but WILL matter once you build boost.
Does that Haltech unit control both fuel and timing or just fuel? I used to use the E6 which did both.
An 8 ohm injector isn't what I would consider high impedance, it is kinda in-between. See what Haltech considers it in case you need to setup the ECM for Low/High Impedance injectors. Some you do, others don't care.
Unless you have some crazy cam, which you can't use with that intake anyway, you certainly do not need to run it richer than 12.5 at idle no matter what, unless you aren't using super unleaded or race fuel. I don't know anything about E85 or Methanol tuning........
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terryking7
Forum Newbie
Posts: 35
Loc: Brisbane, Australia
Reg: 03-17-09
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08-12-12 04:59 PM - Post#2258581
In response to Danny Cabral
Day 2. I took some of your advice and did a bit more testing. Here are the results from what I did.
Firstly, the engine data at three points:
Key on, no start Started (cold) Started (10 min warm)
RPM 0 1000 815
Load (KPa) -3.0 -45 -40
Injector duty 0% 6% 6%
Injector duration 0 ms 1.55 ms 1.55 ms
Bat volts 13.96 14.76 14.82
O2 sensor v 108 mv 938 984
TPS 0% 2.7% (foot on pedal so no stall) 0% (idling without foot on pedal)
Coolant Temp (C) 12 44 79
Air temp (C) 13 15 22
A/F (wide band) 16.9 10.9 11.0
Note that the O2 sensor that reads the AF is on the left (hot bank) before the catalytic converters. There are two cats after the dump pipes, and then a X pipe after the cats. There is no O2 sensor in the right (cold bank).
1) Use a test light (or noid light) to verify all injectors are pulsing.
Don’t have access to one now, but will go down that road if the additional information I provide here indicates I should.
2) Use a timing light to verify all plugs are igniting.
Done, timing light indicates all plugs are igniting. Engine runs smooth enough at idle (apart from popping) so I believe all plugs (which are brand new) are firing.
3) Use a temp gun (or damp towel) to verify all cylinders are firing.
Here is temperature data for a test run I performed (all in degrees F).
Time 0 (cold) 5 min run 10 min run 20 min run
1 (front cyl left bank) 50 480 680 770
2 50 640 840 840
3 50 540 720 800
4 50 400 480 630
5 (front cyl right bank) 50 350 350 430
6 50 300 350 430
7 50 280 350 420
8 50 150 210 210
(Note Cylinder 8 is tough to get temp gun onto bare pipe. I believe it is around the 350 mark if I could get a good shot.
4) Check the compression on all cylinders.
Can’t get my compression tester in the tight confines that I am working with unfortunately. The engine is brand new (I know that does not mean a lot) but that’s what I am working with.
5) Check for exhaust leaks on both banks.
No exhaust leaks on either bank.
6) Try swapping injectors bank-to-bank, does problem follow?
This is a great idea, but before I rip the intake system apart I would like to see if the additional information I have provided helps.
What do you suggest next?
Cheers,
Terry
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terryking7
Forum Newbie
Posts: 35
Loc: Brisbane, Australia
Reg: 03-17-09
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08-12-12 05:22 PM - Post#2258588
In response to mike beck
You're going to hate that intake, but since that is what you're using right now let;s see if we can help.
Now I am curious, why? I have ported the manifold to match the high flow Edlebrock runners and ported it to match the Dart Iron Eagle heads. Tried to open up each port as best I could, and polished it all for maximum flow. I have also ported the intake plenum and opened it up significantly, both where it bolts to the runners, at at the throttle body to match it to the 58mm BBK TB.
Do you have the runners on the correct sides? They are not the same though they look identical. You could have a vacuum leak if they are reversed.
They are on the correct side. They are aftermarket Edlebrock runners and you can't actually get these ones around wrong.
Is this a Corvette intake? They have an externally fed EGR system on the 'Vettes. Are you using EGR? If not, do you have the correct block-off plates and gaskets on them?
I believe the intake is the Camaro model and I have removed all the EGR stuff off, and blocked it off with a block off plate and gasket. There are no vacuum leaks when the motor is running.
What heads are you using?
Dart Iron Eagle
It is fine to lockout the timing, but you need to remove timing per psi, you seemed to state you are not removing any. Doesn't matter at idle/part throttle, but WILL matter once you build boost.
I have a BTM with a variable setting where I can back out 0, 1, 2, and 3 degrees of timing per PSI of boost. At the moment I have this set at zero, only because I want to eliminate as many variables as I can while I try and sort this problem out. I agree, once I get this puppy sorted out and can actually run some boost, I will definately back timing out.
Does that Haltech unit control both fuel and timing or just fuel? I used to use the E6 which did both.
Haltec F10X is a fuel ECM only. Timing is controlled by the MSD BTM.
An 8 ohm injector isn't what I would consider high impedance, it is kinda in-between. See what Haltech considers it in case you need to setup the ECM for Low/High Impedance injectors. Some you do, others don't care.
Unless you have some crazy cam, which you can't use with that intake anyway, you certainly do not need to run it richer than 12.5 at idle no matter what, unless you aren't using super unleaded or race fuel. I don't know anything about E85 or Methanol tuning........
Agree, the cam is not crazy at all so should not need to be running this rich. Idling at 10.9 to 11.0 it pops. Backing fuel out below this, and the engine stumbles and dies. The AF reading is taken from the "hot" bank before the cat. What about putting a bung in the "cold" bank before the other cat to see what AF ratio this is running at. If it is different, what is this telling me?
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mike beck
Contributor
Posts: 218
Reg: 05-20-10
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08-14-12 07:21 PM - Post#2259365
In response to terryking7
Check the A/F on the other side too.
I haven't used that particular ECM, are you sure all the paramaters are set correctly? Have you checked the "cold bank" injectors to see if they are all pulsing?
You can unplug one at a time and see if the idle drops, beats pulling a plug wire and stops you from putting raw fuel through a cylinder.
If you can't mix-up the runners from side to side, that is good. Stock GM runners can be reversed.
Those intakes are just a pain in the butt to work with, too many bolts, too many gaskets, too many places for leaks to occur.
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