Bogging down/miss fire?

[Guest Cronic]

I've been trying to get my car right for weeks now, and just cannot get the damned thing running right.

 

With the timing set to 24 degrees, and the L28T MAF set at stock location, the car idles OK - but when ANY boost comes up, the car will pop and miss, basically bog down and I cannot figure WHY!?

 

I'm thinking there's a possibility of a boost leak, but every once and a while the car will run fine. It just doesn't make sense. I dont have the money right now to redo all of the couplers and piping to my IC - does anyone know how to test for a boost leak?

[gexgexgexgex]

the boost leak does not sound like our problem, more than likely its an electrical connection gone bad or you TPS.

 

but to cheak for boost leaks all you need is

 

a compressor

two end caps of what ever size piping you have , i got mine from OSH for like 4$

the compressor fitting and a nut that fits the other side

 

all you do put on cap on one end of your piping and the other cap with a compresor fitting installed to the other, then hook up the compressor for a few seconds and see if you can hear any leaks.

[nienberg.11]

When I was tuning on the stock efi, I could get the car idling as well as possible, but as soon as I'd touch the gas it would bog down. Likewise, I had issues with it popping in boost, which turned out to be from an overly rich condition. I leaned the afm some and now it doesn't idle consistently but runs smooth. The best thing to do would be to get a wideband on it and see what's really happening.

[Guest Cronic]

Yeah - a wideband is still an expensive option for me right now - as my life is going into some type of transition, I'll be moving out of my apt and into someplace new within the next couple months... My narrowband goes dead red when I give the car some gas. It's hard to figure out and Im at my witts end with this.

[nienberg.11]

So I take it that you've already tried enrichening the afm setting?

[Guest Cronic]

Yes - both enriching, and leaning it out to see if it would have any effect at all.

 

it would make the idle condition richer, but as SOON as I gave it enough gas to get a + pressure in the intake manifold it would go dead lean.... I dont understand what could be going wrong?

[nienberg.11]

Have you checked your fuel pressure? I once had a similar problem where the car would run fine until I put my foot into it. Then it would nearly stall out. Turned out to be a restriction in my fuel lines leading to insufficent fuel pressure under high loads. In my case this was caused by a clogged canister filter in the line going from the tank to the pump. I drove it as usual but left the hood open enough to watch my inline pressure gauge and as soon as I stepped on it, the pressure went down to nearly zero.

[blake culp]

mine used to do that for two reasons, first when the cpu plugs were dirty they caused all kinds of bad stuff to happen, i seriously had to floor it to get over a speed bump. Clean them first! Second after a long drive (2+ hrs) it would bog and stall when boosting, i never solved the problem but i believe it to be that my fuel cap is not venting correctly and it causes a vaccume in my tank so the pump couldnt provide enough pressure under boost, thus low fuel pressure. The reason i say i never solved the problem is becaus i went megasquirt and i havnt driven it for that long yet, although im sure it would make it as long as i stopped and took my fuel cap off ever couple hours. But if you want my opinion, get rid of all the stock ecu stuff and all that corrosion and put in a megasquirt, megasquirt is the way to go mobys write up works perfect, i love mine.

Blake