Cosworth AFR problems
04-12-2013, 10:55 PM
#1
Fast Ford snapper
Thread Starter
Cosworth AFR problems
My T34 on greens stage 3 Saph has recently started running lean.
The first symptoms were that it wasn't making the same boost, even though it's on a Gizzmo EBC. I went and had it checked out, and the bad AFR figures were found out.
I now have an AFR gauge on it, and on normal driving it's around the 10s and low 11s, then when boosting it goes to high 14s at 20psi!
It's been on a dyno twice before a while back, and had the AFR checked about 6 months ago on the road, and it was ok then I'm told but I don't have a record of any figures to prove this.
It's just had a new 044, pump rewire, pre pump filter and replacement OE fuel filter fitted which didn't make any difference.
Running out of ideas now!
The first symptoms were that it wasn't making the same boost, even though it's on a Gizzmo EBC. I went and had it checked out, and the bad AFR figures were found out.
I now have an AFR gauge on it, and on normal driving it's around the 10s and low 11s, then when boosting it goes to high 14s at 20psi!
It's been on a dyno twice before a while back, and had the AFR checked about 6 months ago on the road, and it was ok then I'm told but I don't have a record of any figures to prove this.
It's just had a new 044, pump rewire, pre pump filter and replacement OE fuel filter fitted which didn't make any difference.
Running out of ideas now!
05-12-2013, 06:03 AM
#2
cossie fan (unluckerly)
Take it to a tuner that knows what there doing and get it set up! If it's in the 14's on boost your end up melting a something! I'd not drive it hard until it's been looked at
05-12-2013, 12:42 PM
#5
As above mate, unless it's something simple (or you're lucky), best off taking it somewhere to get it checked properly. I had similar but not as erratic as your issues, when I took it to Tony @ Turbosytems he found all sorts of minor problems that caused it to run dodgy, leaky injector o'rings, leaking inlet manifold gasket, leaking exhaust downpipe, incorrectly set TPS, etc, etc... I guess for the price of a regulator it's worth changing first though.
05-12-2013, 12:47 PM
#6
Fast Ford snapper
Thread Starter
Fuel pressure hasn't been checked yet.... Can you get new diaphragms for the regulators? Or is there a typical aftermarket replacement people use?
05-12-2013, 10:09 PM
#10
I suggest to check the following:
1. Battery voltage
2. Fuel pump voltage
3. check the vacuum hoses that connects blow off valve, fuel pressure regulator, map sensor...
4. check the fuel lines under the car (if they are in good shape)
I believe that 10s and 11s at low speed is too much (very rich), when at high load you see 14s then probably the fuel pressure regulator doesn't work correct or the vacuum hose that connect the regulator with your inlet manifold is disconnected. The last thing is that you have raise your boost above fuel&boost map and the car doesn't know what to do.
1. Battery voltage
2. Fuel pump voltage
3. check the vacuum hoses that connects blow off valve, fuel pressure regulator, map sensor...
4. check the fuel lines under the car (if they are in good shape)
I believe that 10s and 11s at low speed is too much (very rich), when at high load you see 14s then probably the fuel pressure regulator doesn't work correct or the vacuum hose that connect the regulator with your inlet manifold is disconnected. The last thing is that you have raise your boost above fuel&boost map and the car doesn't know what to do.
Last edited by MADMAXPTT; 06-12-2013 at 09:00 AM.
06-12-2013, 10:09 PM
#13
Fast Ford snapper
Thread Starter
When I got to drive it myself today it turns out that there has been an improvement after the fuel system had several bit replaced.... also good having the wideband on board so gave the fuel pressure a tweak to make sure it was safer.
Still doesn't behave quite as I'd like in all circumstances, so I think a proper set up in order, and perhaps a chip too, as I have no idea what it has in the ECU!
Good idea!
Still doesn't behave quite as I'd like in all circumstances, so I think a proper set up in order, and perhaps a chip too, as I have no idea what it has in the ECU!
Good idea!
06-12-2013, 10:41 PM
#15
big floppy donkey dick
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Ade,
think about this mythodicaly ok,
you have components, solenoids, ECU and wiring.
check voltages at the ECU, then components as you know what the voltages should be at various solenoids, correct??
i.e if the MAP fails, you have voltage readings to confirm this.
if the ECU fails, you have voltage readouts to confirm this.
if (and most likely!!!) the wiring fails, continuity, and voltage checks at the solenoids and components will again, confirm it dude!
ive had this many many times with split MAP pipes, MAP sensor fucked and most of all shitty engine bay wiring!!
think about this mythodicaly ok,
you have components, solenoids, ECU and wiring.
check voltages at the ECU, then components as you know what the voltages should be at various solenoids, correct??
i.e if the MAP fails, you have voltage readings to confirm this.
if the ECU fails, you have voltage readouts to confirm this.
if (and most likely!!!) the wiring fails, continuity, and voltage checks at the solenoids and components will again, confirm it dude!
ive had this many many times with split MAP pipes, MAP sensor fucked and most of all shitty engine bay wiring!!
07-12-2013, 12:09 AM
#16
Fast Ford snapper
Thread Starter
07-12-2013, 12:10 AM
#17
Fast Ford snapper
Thread Starter
Ade,
think about this mythodicaly ok,
you have components, solenoids, ECU and wiring.
check voltages at the ECU, then components as you know what the voltages should be at various solenoids, correct??
i.e if the MAP fails, you have voltage readings to confirm this.
if the ECU fails, you have voltage readouts to confirm this.
if (and most likely!!!) the wiring fails, continuity, and voltage checks at the solenoids and components will again, confirm it dude!
ive had this many many times with split MAP pipes, MAP sensor fucked and most of all shitty engine bay wiring!!
think about this mythodicaly ok,
you have components, solenoids, ECU and wiring.
check voltages at the ECU, then components as you know what the voltages should be at various solenoids, correct??
i.e if the MAP fails, you have voltage readings to confirm this.
if the ECU fails, you have voltage readouts to confirm this.
if (and most likely!!!) the wiring fails, continuity, and voltage checks at the solenoids and components will again, confirm it dude!
ive had this many many times with split MAP pipes, MAP sensor fucked and most of all shitty engine bay wiring!!
Basically the jist is I could probably do with a new loom?
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