Help! My car doesn't want to run properly, and it's driving me nuts!

[MA70_Powa]

Hey guys,

Hopefully you can help me out here.
My car was running fine and dandy right up until last Saturday. When I went to go for a drive on Sunday, it wasn't running properly. Weird.

What happens is when I push the accelerator it bogs down massively and sometimes stalls, sometimes the revs jump around and it runs rough, but still doesnt go anywhere fast. If I can actually get it moving at faster than 10kph, when boost comes on it takes off and drives fine the whole time it's on boost. It's only off-bosst that is a problem. Idle is also relatively fine.

What I've done so far:
- Checked and re-checked all hoses and vac lines. No leaks.
- Checked codes - I get a code 51. Now, this code 51 has been there since I did the engine swap. I don't have A/C hooked up, so I've always associated it with that. I read JetJock's article on code 51 and checked the TPS just to be sure, and it checks out fine.
- Cleaned the ISC valve and the check valve (wasn't very dirty to begin with)
- when the car was idling, pinched the ISC hose near the accordian pipe - the car's revs went down and it stalled.
- I can hear the ISC do its clicky thing when you turn the car off
- unplugged the ISC valve from the harness and done a cold start - however, my revs didnt go up to 1500-2000, they stayed around 1000-1200... does this mean it's buggered? It sounds like it's working and it looked fine to me when I pulled it out and cleaned it.

I really need to get my car back on the road, so any help would be great

 

[alloyguitar]

I wouldn't be convinced that the idle not rising is indicative of a screwed ISC. I took mine off and blocked off the holes without any rise in idle.

Have you tried unplugging the tps and starting it? Or unplugging it while the car's running?

I had a similar issue, but since my car's pretty far from stock, I'm not sure how much help I can be.

 

[MA70_Powa]

Yes I've started it without the TPS plugged in, drove it up and down my driveway that way - still the same.
I also tried having the TPS and ISCV unplugged at the same time, and still the same.

p.s. my car's not bog stock either

 

[alloyguitar]

Yes I've started it without the TPS plugged in, drove it up and down my driveway that way - still the same.
I also tried having the TPS and ISCV unplugged at the same time, and still the same.

p.s. my car's not bog stock either

Well, I don't have an isc/afm, and my tps is from a q45, so.....

That's a strange occurrence. I would have expected that unplugging the both of them would have presented new issues (indicating that they're working properly when plugged in).

 

[jdub]

Sounds like your ISCV is working fine.

Have you checked timing with the diagnostic block jumped?

 

[MA70_Powa]

I'm not able to check the timing myself, but I'll get someone to do it for me asap.
I wouldnt've thought the car could get wrong timing so suddenly, expecially since it was only put together a few months ago...

Oh and I fired it up again today to see if it miraculously fixed itself, but no I also tried unplugging the tps and iscv again, and with either of them unplugged basically as soon as i touched the gas pedal it bogged and died.
Also the first time I started it the revs basically went from 1200 gradually down to 300 and then died.
Dunno if that info helps in any way?

 

[jdub]

You might have jumped a timing gear tooth...especially if you did not re-set belt tension after 500 miles or so.
Set the crank index at zero and see if the two cam gear marks line up on the index marks on the back cover.

 

[MA70_Powa]

Just thought I'd post that I haven't forgotten about this, but it's been pissing down with rain for two weeks straight so I haven't been able to touch the car - should finally get a chance to have a look tomorrow.
I'll report back once I've checked it out!

 

[MA70_Powa]

:rant2:

FFS. Now I have the old 'cranks but won't start' problem which came out of nowhere, so I have another setback!!!

dammit.

I'm determined to get this thing working!!!!

 

[MA70_Powa]

Ooook.
So.
I know it's been ages since I've had this problem, but it's still there. I've been on holiday so I hadn't had a chance to do anything with it.

Anyway, just thought I'd say that PROBLEM SOLVED! YAY!

Ok, so the problem was the fuel pump and the fuel filter! And my fuel pump relay was kinda dodgy too...
Turns out my fuel filter was clogged to buggery, and my fuel pump died! See, I thought I had a brand new walbro in there ever since my engine swap, but the mechanic currently working on the car pulled it out and there was still the stock one in there Not Happy!

New filter and pump, and the thing works fine! They just need to put the 550s in now and then things'll be sweet.

So for anyone in the future having a similar problem to me, check out your fuel system too!
Thanks for the help everyone!