Just got done installing a custom turbo kit, and am having some serious issues with it not wanting to idle, hot or cold.

Things I've done:

Scaled MAF - voltage looks good. I used a new MAF housing that was identical to the factory size.

Installed larger 840cc P2 injectors in the middle two slots on the big rail (scaled to 1026 in the Cobb)

Installed larger modified 780cc Primary Injectors (scaled to 992 in the Cobb)

Running factory secondaries.

Walbro pump installed per MM instructions

Check for Vacuum leaks everywhere. Nothing found.

It seems like no matter what I do, whether it's add more fuel, increase latency values, or modify the maf scaling, it still stalls. The car acts like it wants to idle but then dies off as it's settling after start up. I'd be happy to provide the map I'm trying to start off with if needed. Maybe I'm missing something very blatant. I may stick in another fuel pump just incase. It just looks to be going lean in all areas. It doesn't respond to anything I change in the Cobb software. Any ideas I may be overlooking?

 

just swapped the fuel pump to eliminate that as a suspect.

I'm assuming the large primary's really have me screwed up.

 

What are you using for an intake? And does it have a screen in front of the MAF?

 

This is my intake...



All of it is 3.375" ID piping. I do not have a screen in front of the maf. I could try that and see what happens.

 

I thought you were asking for trouble with those large P1s - that is where I would start . Do you still have the stock reds - they will supply ample fuel in the range you need them to for that turbo .
The other thing is do you have enough drive cycles for the ecu to have adjusted its trims .....

MAF setup and placement looks good to me .

 

I had the stock reds modified about a month ago. I guess I need to try and find some.

 

do you still have a set of stock yellows ? they work fine in there as well .

 

well, the yellows i have are in the p2 and secondary positions. stock secondaries, modified p2's and modified primary's.

 

swap over the stock yellow secondaries with the modded reds to get you going then alter the latency table and scale to suit .
Not sure how big the latency differences will then be in the other slots however ....

 

So put the massive 780cc red's in the secondary position on the big rail, factory 390cc secondary yellows in the primary positions, rescale, alter latency tables. I think I got that correct. I may still have an issue with the large *** secondaries though.

 

Don't know if you will or not . MM says you need to keep the ratio between p1s and secondaries similar to stock which is 290/380 . 380/780 is better than 780/380 in that regard .
What are the 840s - Modded yellows ?

 

yes 840's are modded yellows

 

The latency table differences between reds and yellows are not big . You should be ok .

 

We'll see. I just read your thread about using the secondaries in the primary position. Not sure it helped much, but I'll give it a go and see what happens.

 

The latencies will change with the injector mods as well...not sure how much. Someone should ask KG for the info

 

changed them from one extreme to the next with no effects.

 

Gah! Got it to idle this morning. It was rather rich(10's), but it idled. Now it's doing the same thing it was yesterday, again. Won't idle, AFR's are going lean and the car stalls. It's showing no effects to whether I jack up or down latency, adjust the scaling, etc. It almost acts like there is a vacuum leak, but I can't detect anything with the vacuum leak tester.

I stuck the Walbro back in today. I did not drill out the return tube during the original install, however. Maybe this is the problem. Any other suggestions?

 

you didn't say if you put the yellows into p1 or not ?


Out of curiosity , what kind of gadget is a "vacuum leak tester " ?

 

yes i moved the secondaries to the primary position.

vacuum tester. used both an air pump and the smoke machine to test.

 

Did you get it to idle cold or hot with the 10AFRs ?
Where do you have the jet air and omp vac lines plumbed into ?

A vac leak needs to be pretty big to make it stall in my experience - so if that was it . it would be pretty obvious

 

It idles now, but its very erratic. AFR's are jumping all over the place. Looks like one of the load tables was a bit scewed from stock. Tried playing with the scaling on both the maf and injectors and still idles erratic.

By jet air do you mean the air pump assembly? If so, I don't have it. It's been deleted.

The OMP vacuum source is in the stock location. I didn't mess with any of that.

 

Air pump silly question : Did you block the vac line that used to go to the airpump valve ?

Jet air is the line that used to be beside the omp vac line - it goes to the jet air tubes in the lower inlet manifold . It provides air to prevent fuel puddling .

Can you log g/s ? If so you could log what your maf looks like at a steady state rpm say 1200 (if you can hold it that low) . Then see if it is bouncing all over the place . If so your maf will need work to straighten the airflow .

Also : do you have a catch can setup for your oil fill neck vac line and where is that piped ?

 

Your MAF setup is jacked. That won't work.

You injector latencies are probably wrong, too.

There is no drilling involved in the fuel pump install - reread the instructions.

 

I thought it looked good (not too dissimilar to what has worked for me ) - what is wrong with it ?

 

Jeff: Could you re-iterate ..or link to the perfect intake thread

I couldn't find it....