Won't Stay Lit

Author
Discussion

tvrdetroit

Original Poster:

20 posts

283 months

Wednesday 19th June 2002
quotequote all
I purchased a 4.6l shortblock with stage 3 heads, 218 hybrid cam, Jag injectors, Jag AFM, adjustable fuel pressure regulator, K&N air filter, etc. from V-8 Developments and have installed in my 390SE along with a T-5. Have the Mark Adams ECU for the flapper valve AFM.
Problem is it will not stay running at idle. Once you lift it shuts off. Have tried everything Shaun from V-8 and Mark have to offer and still no joy!
Have gone through 4 temp sensors, 3 AFM's, 2 sets of injectors, and will not stay running at idle. Heavy fuel smell and exhaust black. Runs fantastic mid and upper range, just no idle. Have adjusted AFM recommended 10 clicks, checked FP regulator with gauge, wire continuity, etc.
Anyone have any thoughts that I might try? I am getting desperate to drive this car as it has been off the road for over a year!
Please help!!!!!!!!!!!!!
Blue skies and green lights,

Chuck

zippy500

1,883 posts

270 months

Wednesday 19th June 2002
quotequote all
This is probably completley useless, but I once had a mini that I fitted a modified head, bigger, carb etc, and like yours kept cutting out. Amazingly what cured it was to disconnect the vacuum advance hose. The car ran fine throughout the rev range and never stopped running again. Worth a try. I dont really understand why it worked.

GreenV8S

30,234 posts

285 months

Wednesday 19th June 2002
quotequote all
quote:
I purchased a 4.6l shortblock with stage 3 heads, 218 hybrid cam, Jag injectors, Jag AFM, adjustable fuel pressure regulator, K&N air filter, etc. from V-8 Developments and have installed in my 390SE along with a T-5. Have the Mark Adams ECU for the flapper valve AFM.
Problem is it will not stay running at idle. Once you lift it shuts off. Have tried everything Shaun from V-8 and Mark have to offer and still no joy!
Have gone through 4 temp sensors, 3 AFM's, 2 sets of injectors, and will not stay running at idle. Heavy fuel smell and exhaust black. Runs fantastic mid and upper range, just no idle. Have adjusted AFM recommended 10 clicks, checked FP regulator with gauge, wire continuity, etc.
Anyone have any thoughts that I might try? I am getting desperate to drive this car as it has been off the road for over a year!
Please help!!!!!!!!!!!!!
Blue skies and green lights,

Chuck


So many possible causes it's hard to know where to start.

If I were you I'd get a colourtune plug, spark trace and timing strobe and see whether the mixture, spark strength or spark timing are doing something funny at idle.

Fatboy

7,988 posts

273 months

Wednesday 19th June 2002
quotequote all
Turn the idle up to about 3k?

(Did it once on my brother's Mini when we ed up fitting a ridiclously large bore exhuast on a 998cc went like stink above 4k though )

Nobby

47 posts

285 months

Wednesday 19th June 2002
quotequote all
"Heavy fuel smell and exhaust black"

Just a guess but sounds like the fuelling map's miles out at idle, Surely Mark Adams can adjust this.

gjm

78 posts

269 months

Monday 22nd July 2002
quotequote all
not too sure about 390s, but on my '92 griff the speedo sensor was tempremental and caused it to stall at idling speeds - does the speedo impact on the idling speed of the 390?

edward1

839 posts

267 months

Monday 29th July 2002
quotequote all
Just had the same symptoms on standard 350, garage checked injector open time and found it to be a factor of 10 too long. Recond AFM and new ECU and it now runs (6 months of the road) but is seriously down on power and runs very lumpy when cold. Good luck finding a soln.