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> D-jet idle - one issue thats not been solved, low idle on start up for a few minutes hot or cold......
DRPHIL914
post Apr 6 2021, 06:04 AM
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Dr. Phil
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here is my set up, - its a '75 2.0 d-jet with very fresh and new in past 2 years everything,
,tested proper functioning AAr, CHT is the new 914rubberone, but same issue with my NOS one, no vac leaks , rebuilt throttle body MPS(ive tested 2 others one rebuilt by Jeff B same issue), etc etc , 123 distributor, anywayhere is what i have going on-

i think i am around 1000 for a good steady idle, if its lower than that warmed up, then i cant get it to idle decent when cold for the first 2-3 minutes, even with AAr open, same with a hot start after running for a while, then shut off and turned back on after sitting foor a few minutes, heat sink on the CHT maybe, i have a feeling the resistance of the CHT is not correct, it is a NOS correct CHT but i am thinking about adding that resistor to the cht line- any thoughts? i have to feather or hold the pedal down just a bit for a minute or 2 then it comes up.

like i said perfect idle around 950-1000 once on for a while or even stopped at light after running for a long time idle is perfect EXCEPT after turned off for a bit then back on--

Phil
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BeatNavy
post Apr 6 2021, 06:27 AM
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Phil, what are the specs on your engine? Is it bone stock 2.0 or did you bump to 2056 and if so what compression and cam?

I've had a Raby 9950 in a 2056 and a 2270 with CR around 8.6 and 9.0 respectively. On both builds I could never seem to get enough air on cold starts unless I completely yanked a vacuum hose off the plenum. After 2 minutes all is good. Never had an issue with hot starts though.
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DRPHIL914
post Apr 6 2021, 06:39 AM
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QUOTE(BeatNavy @ Apr 6 2021, 08:27 AM) *

Phil, what are the specs on your engine? Is it bone stock 2.0 or did you bump to 2056 and if so what compression and cam?

I've had a Raby 9950 in a 2056 and a 2270 with CR around 8.6 and 9.0 respectively. On both builds I could never seem to get enough air on cold starts unless I completely yanked a vacuum hose off the plenum. After 2 minutes all is good. Never had an issue with hot starts though.



one other question i have while we are talking D-jet engines and 2.0 motors is issue with head temps. - i have a gauge running off of the #3, i will go over 300 in certain rpm and speed bands, especially on highway driving. never an issue pushing really hard during AX runs, so i guess on higher RPM for short bursts keeps the air moving and heads cool.
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