Almost Stalling On Acceleration

[JonnoHR31]

TPS working properly?

[SECURITY]

fixed it guys.

i was thinking why it would go lean and then rich right after and i thought... MAP SENSOR may have been jumping around the fuel map in a shit way

so i took my hoses off one at a time to look for a leak and i found a shitty little one RIGHT on a clamp.

why is it that my car never has an obvious fix??

thanks guys.

[SECURITY]

it started doing it again. i found another leak in my ebay special throttle body, its a tiny leak which is starting to do my head in but i still doubt its causing the problem, but im going to try get a greddy throttle body adapter and check my stock TB to see if that fixes the problem.

has anyone got any suggestions? keep in mind the car runs a MAP sensor and a VIPEC ecu.

so far ive played with the injector dead times (made the entire map rich), and accel map which didnt do anything.

[DriftSquad]

hey mate seems like 2 problems iv had in the passed.. one was air flow meter, the other was a small vacuum leak from the turbo inlet after the airflow meter.

hope it helps!

[JonnoHR31]

hes not using an air flow meter

did you check the tps? is the vipec seeing the same vacuum as your boost guage if you have one?

[SECURITY]

im pretty certain its the air leak in the throttle body thats causing it, im waiting on an adaptor to arrive so i can put the stocky one back on.

i think its a case of the map sensor not moving on the fuel map quick enough which is causing it to run lean off take off. ill report back when the adaptor comes.

[Adriano]

AN air leak at the throttle body shouldnt effect the running as its map sensor, idle will just go up. Has it been running right after th eecu install?

[SECURITY]

its been running perfect up until 2 weeks or so after the plenum/injector install. i think an air leak would effect it if a considerable amount of air is passing through the TB. i hooked up my compressor to the cooler piping and it was hissing enough for me to pick where it was coming from straight away.

[SECURITY]

can anyone tell me what the signs of a bad fuel pump is on a skyline? has anyone had/heard of the effects?

i think it may be the pump.

[MBS206]

That sounds EXACTLY like my car does when the fuel and ignition were not tuned right, and the acceleration enrichment was not setup right.

The accel enrichment is an absolute bitch to get nice and sweet on most cars with big injectors, do able, but takes time for those who haven't done it before.

[SECURITY]

bugger.. if its the injectors i might just swap back to standard. im thinking about getting it running just to sell it off now.

[Dale FZ1]

I had the same issue with a freshly painted Greddy copy manifold, scraped back the paint at the grounding point, and fixed it.

Click on tabs "Analogue Inputs" and "Analogue Status". Make sure it isn't displaying a voltage problem with the TPS. If an error exists, it should show up in the status tab as a red bar. Inputs should also show limited range rather than the typical 0.5 - 4.5 volt range between 0 - 100%.

If you have a dicky system ground on the inlet manifold, TPS voltage won't run through the correct range and you will get all sorts of horrible lean running on accel. ie. Unless TPS output is correct, no amount of changing accel enrichment will alter what actually happens when you attempt to accelerate the engine speed.

Otherwise you should setup a data plot and observe what the AFR actually does on accel. Then you might make an informed judgement about what to look at next.

[SECURITY]

earth is fine, i thought it might have been at first but i hooked it up directly do a ground point on the chassis and it didnt change anything.

with the ebay throttle body the TPS has to run in reverse to the standard ecu, so for eg. if the standard throttle had 0.1v being closed and 5v being open, the ebay throttle body only works with the 5v as being closed and 0.1v being open.... its the only way it would work but the ecu calibrates whatever voltages are open and closed and sets it as 0-100% throttle position.

ive got it down to a few things;

1. throttle body leak - adapter is coming some time this week so ill be able to rule it out. this will also make the voltages back to normal settings.

2. acceleration enrichment - does anyone know a way i can check this? do the %'s go up or down with bigger injectors?

3. fuel pump/filter - i took the pump out yesterday and checked for anything that could cause it to fail but i didnt see anything out of the ordinary. if the above 2 dont work i'll replace it with a new one.

[MBS206]

I found my percentages for corrections had to dramatically decrease.

For example, my cold start enrichment I reduced by aroudn 75% over what it was originally.

[SECURITY]

well i just threw in my standard injectors and reverted back to the old map and it made NO change. i also checked the fuel filter and it wasn't blocked at all.

now ive got to wait for my throttle adapter to come, then if that doesnt work ill grab a fuel pump.

ohhh how i absolutely love diagnostics

Edited January 4, 2010 by SECURITY

[Guilt-Toy]

what kpa is the map sensor showing in the tuning screen with the engine off but the reds on?

make sure software is connected