Cyberpunky

The saga with my car has been going on for months now and after today I am pretty much stumped.

I used a mechanic to fit Tial F38 dual port, a CEP fuel rail, the solenoid for my eboost1, some lightened pullys, do the belts, fit larts polished cam tower cover and manifold. I also got him to refurbish the throttle body with Arnworx kit
Turbo was rebuilt and radiator replaced about 18 months ago. No shaft play or obvious damage.

I got car back and was overboosting to 20#. Played with eboost thinking it was settings but finally worked out Tial had been fitted backwards. I got Tial put back on right way and eboost was working properly, but I was only running moderate boost(11-15#). At this time car started bucking and backfiring randomly. Usually only once warm. This got progressively worse.

As I was strapped for cash after paying for work on my car, I decided to try and work it out by myself and have done all the work. I have even less money now

I changed my FPR to 3 bar and fitted Rogue ECU and A tune.
I fitted LR speed and ref harness.
I fitted DME temp sensor
I fitted TPS sensor
I refurbished AFM then replaced it(see below)
I fitted new spark plugs, leads, rotor button, cap, and a blaster coil
I removed hard tree, did venturi delete and AOS hose
I fitted Lausts Vacuum manifold and replaced vacuum lines
I fitted SFR 2.5" IC Hard Pipes
I fitted M tune and 80#inj and MAF
I got cat replaced with a new 200 cell unit
I fitted new speed and ref sensors
I have ordered but havent picked up a new fuel filter.

Apart from O2 sensor and fuel pump, I think I have replaced almost everything.

I have a wide band ready to fit but have been too busy doing this to get it fitted, so I don't know AFR's. I dont have a fuel pressure gauge either.

Car idles better since I replaced S & R sensors today and seems fine if I don't open throttle but the minute I try using anything other than light throttle she back fires and hesitates. No real boost either

As title says I am out of ideas, so any suggestions wlecome

Paulyy

Rule out the o2 sensor
http://www.clarks-garage.com/pdf-manual/fuel-18.pdf

If you cannot get it going. I'll make a day and come down on the weekend with some tools.

Cyberpunky

Yeah O2 was clutching at straws Pauly. I will get the fuel filter and fit that incase it isn't flowing properly at higher RPM causing fuel starvation. I would appreciate that Pauly

Paulyy

If you can rule it out tomorrow or something before the weekend. so we know what's happening.

raleighBahn

Mercy - that's a big spend. The instant you rang that up, Lart's double-lidded eye opened like the dragon under the mountain, awakened from a hundred year sleep

You need a theory on why this is happening, and then a means to test that theory, preferably without buying parts. Once you disprove it, move to the next.

First and easiest thing to do is run the car, and after it misbehaves, check the blink codes from the diagnostic port - it may point you right to the culprit if you are lucky. Page 28-16 of the Turbo supplement shows the likely causes of misfire and a test plan for ruling them out.

So the backfire probably means you're igniting fuel on intake stroke - it's not burning quickly enough on combustion and igniting the fresh fuel being drawn in - probably lean mixture.

You said you replaced the spark plugs - they may give you some confirmation if running lean. If you still have the plugs (and they are in order), do you have a photo? Else a photo of the newer ones? I would do some basic tests on the fuel injectors (resistance, noid light, etc), and also get the fuel pressure / leak down numbers. You can chase your tail with all of the sensors, but first establish if what it supposed to deliver fuel is delivering fuel, and what is supposed to burn it is burning it.

azbanks

When you had the CEP fuel rail installed, did you have the fuel dampner removed? Without it you may get erratic fuel pressure spikes/waves.

fejjj

I had a similar situation happen and it turned out the the rotor was broken.

I replaced the cap and rotor and zoom zoom!

eman930

How about your coil? I had an issue were one of the power leads on the coil was lose, I'd randomly lose power or start missifiring, happened more when hot, I only found it by randomly hitting the wire and seeing it move, had a good burn mark on the coil too, I replaced it and tightened the power and ground leads and now use a lock washer

Paulyy

The only problem diagnosing the car via words and user explanation. you have to go by what they're feeling.

Cyberpunky

I will never sell this car and even if I did quit and sell it, shipping it to US would be too expensive. Lart and my transactions are strictly one way. He finds it and I buy it lol

Yes Eric, damper was removed, although I was under impression rail has a damper built in on the end. When I first got car back it ran fine for about 2 months or so, it was just overboosting so although you may well be right about the possibility, I am not aware of anyone using this or LR rail using a damper.
I would love to hear if anyone has had the issue and fitted a damper to cure it

Rotor and cap have been replaced

Coil has been replaced, and then old one refitted and then new refitted. Connections are secure.I also fitted new leads new Ign leads.

Pauly I probably wont be getting filter till next week now, although I might see if I can get it tomorrow but Sunday would be earliest I could fit it and test if it makes any difference

black944 turbo

Have you checked for a blown head gasket? Checked for hydrocarbons in the coolant etc? Some times they can only show up under load. As others have suggested how about the coil?

Cyberpunky

Not sure how to test hg. No milkshake though.
Coil has been replaced

black944 turbo

I think you can buy a coolant tester pretty I expensively online. This will lead you in the correct direction.

Paulyy

compression tester is the best way. I doubt it's the head gasket. I've had mine blow on me twice.
first time was original gasket and was loosing compression from the ring
2nd was because it overheated. that was pushing pressure into the coolant.

engine ran fine..

Let me know how the fuel filter goes.

odurandina

track..... SLC Supercar, 911, Cayman, etc.....

street..... 948.