Help - Search - Members - Calendar
Full Version: D-jet idle - one issue thats not been solved
914World.com > The 914 Forums > 914World Garage
DRPHIL914
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
BeatNavy
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.
DRPHIL914
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.


yea, its all stock as far as i know, none of the paperwork i acquired with the car 12 years ago indicated any engine work or build. so assume stock cam etc.
and while it has ok compression and leak down numbers , not perfect and its got 59k miles, so i am also starting to plan out what i would do next, either stock rebuild with new HAM heads and 2056 on the stock cam might bewithin the budget. my understanding is with Len's new worked heads, and new FI from PMB its possible to get a nice bump to 115hp on stock 1911 and 125-130 on the2056. so going forward thats in my thoughts,for about a year out- but for now this idle issue is like my last frontier of making this thing run as well as possible. With the 123 it runs great, smooth acceleration etc.

DRPHIL914
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.
BeatNavy
Going over 300 is not an issue especially with hard driving. I understand north of 350 regularly may be cause for attention. Pushing or exceeding 400 not good.

On my 2056 I was D-Jet. On my 2270 I'm Microsquirt with an idle air control valve. On both I have the Raby cam, and, as mentioned, first start of the day requires a few blips of the throttle. I think I've heard others say the same thing.

I hadn't heard about PMB's FI solution. I need to check that out.
GregAmy
Here's my go-to info for CHTs:

http://www.914world.com/bbs2/index.php?sho...mp;#entry377466
ClayPerrine
QUOTE(BeatNavy @ Apr 6 2021, 08:23 AM) *

On both I have the Raby cam, and, as mentioned, first start of the day requires a few blips of the throttle. I think I've heard others say the same thing.


Betty's 914 has a Raby 9590 cam in it, and it won't idle at all when it is dead cold. The AAR is working correctly, but it just won't idle (This is L-Jet, btw). After about 2 minutes of blipping the throttle, it will idle. But the extra performance of the 9590 cam is worth the extra trouble when cold.

I think it is something to do with the cam profile.

Clay

BeatNavy
QUOTE(ClayPerrine @ Apr 6 2021, 08:56 AM) *

QUOTE(BeatNavy @ Apr 6 2021, 08:23 AM) *

On both I have the Raby cam, and, as mentioned, first start of the day requires a few blips of the throttle. I think I've heard others say the same thing.


Betty's 914 has a Raby 9590 cam in it, and it won't idle at all when it is dead cold. The AAR is working correctly, but it just won't idle (This is L-Jet, btw). After about 2 minutes of blipping the throttle, it will idle. But the extra performance of the 9590 cam is worth the extra trouble when cold.

I think it is something to do with the cam profile.

Clay

That's good to know, Clay. I've spent many hours using all the tricks and tools Microsquirt gives you to try to resolve, and I never could.

Agreed, the boost in performance is worth the small price to pay, particularly if you know that it kind of "is what it is."
DRPHIL914
QUOTE(GregAmy @ Apr 6 2021, 09:31 AM) *


thanks for posting that and reminding me of this thread, i saw that a long time ago, very helpful,
i really dont have oil temp issue when running due to the aux oil cooler, only whe car sits idling fro really long time i do see it go up higher around 230 but thats rare, so the head temp shooting up on al long hill pulling hard maybe hitting 350 briefly is not an issue especially with 20/50 synthetic race oil if i look at this correctly, i am not in danger of a dropped valve seat at those temps. yesterday i was bouncing between 250-280 but hit 320 very briefly.

PW
Olympic 914
My engine regularly gets head temps into the 300's

Also like Rob and Clay stated it will rarely idle cold until it has run for a for minutes.

Odd thing is if its REALLY cold like 30's it will idle then. But I have gotten in the habit of shutting it off for a moment to close the garage door, etc. then heel and toe it at the first two stop signs, to keep it running. After that it is fine for the rest of the drive.

BTW i believe you should not be using Synthetic 20/50, recommended a high zinc conventional 20/50 oil be used.

JMHO.


ClayPerrine
QUOTE(Olympic 914 @ Apr 6 2021, 01:00 PM) *

BTW i believe you should not be using Synthetic 20/50, recommended a high zinc conventional 20/50 oil be used.


agree.gif

The 914 engine needs high zinc motor oil. Synthetic doesn't have that.

Clay
DRPHIL914
QUOTE(ClayPerrine @ Apr 6 2021, 04:21 PM) *

QUOTE(Olympic 914 @ Apr 6 2021, 01:00 PM) *

BTW i believe you should not be using Synthetic 20/50, recommended a high zinc conventional 20/50 oil be used.


agree.gif

The 914 engine needs high zinc motor oil. Synthetic doesn't have that.

Clay


i may have misspoken about synthetic, i currently run 20-50 VR-1 Valvoline not sure if its part-synthetic or dino but it has the zppd, i also have used Driven and PennGrade, so i sould be ok on the zinc right??
@ClayPerrine
@Olympic_914
btw, drove to work today, outside temp was 55-60 and 30 minute 30 mile ddrive, drove most of the way at 63-65 mph as my 4th gear gives me about 3600rpm at 65, and my head temp were 285 on flat cruising, but varied in some stop and go and accel from 260 - 290, so with proper gearing i wil be just fine , . if i went up to 70 temp went to 305-310, and would go a bit higher if went into that 5th ZD gear with lower Rpm, - the tool kit is on the way and i will be swaping back in the stock 4&5 next weekend.

Phil
ClayPerrine
QUOTE(DRPHIL914 @ Apr 7 2021, 06:54 AM) *


i may have misspoken about synthetic, i currently run 20-50 VR-1 Valvoline not sure if its part-synthetic or dino but it has the zppd, i also have used Driven and PennGrade, so i sould be ok on the zinc right??


You are good. VR1 is pure dino oil with high zinc. I run the same oil in the 4.0, even though it doesn't need the high zinc.

In the six and in the 74, I run straight 50 weight Valvoline VR1. The high zinc is good for the motors, and the high viscosity helps in the Texas heat.

Clay
DRPHIL914
QUOTE(ClayPerrine @ Apr 7 2021, 08:25 AM) *

QUOTE(DRPHIL914 @ Apr 7 2021, 06:54 AM) *


i may have misspoken about synthetic, i currently run 20-50 VR-1 Valvoline not sure if its part-synthetic or dino but it has the zppd, i also have used Driven and PennGrade, so i sould be ok on the zinc right??


You are good. VR1 is pure dino oil with high zinc. I run the same oil in the 4.0, even though it doesn't need the high zinc.

In the six and in the 74, I run straight 50 weight Valvoline VR1. The high zinc is good for the motors, and the high viscosity helps in the Texas heat.

Clay

Thanks Clay, BTW i took your advice a few years ago and had that aux oil cooler put on and i really dont have an issue with oil temps now.

should i consider this- the straight 50 weight as well for this summer if i drive more in heat this year? we get that same heat, i think i have a case of DT50 Driven that i had not used, or just go to FLAPS for Valvoline?
ClayPerrine
QUOTE(DRPHIL914 @ Apr 7 2021, 07:34 AM) *

QUOTE(ClayPerrine @ Apr 7 2021, 08:25 AM) *

QUOTE(DRPHIL914 @ Apr 7 2021, 06:54 AM) *


i may have misspoken about synthetic, i currently run 20-50 VR-1 Valvoline not sure if its part-synthetic or dino but it has the zppd, i also have used Driven and PennGrade, so i sould be ok on the zinc right??


You are good. VR1 is pure dino oil with high zinc. I run the same oil in the 4.0, even though it doesn't need the high zinc.

In the six and in the 74, I run straight 50 weight Valvoline VR1. The high zinc is good for the motors, and the high viscosity helps in the Texas heat.

Clay

Thanks Clay, BTW i took your advice a few years ago and had that aux oil cooler put on and i really dont have an issue with oil temps now.

should i consider this- the straight 50 weight as well for this summer if i drive more in heat this year? we get that same heat, i think i have a case of DT50 Driven that i had not used, or just go to FLAPS for Valvoline?


The reason I went to straight 50 weight was the 2.4L six I had in my car. Ed Mayo recommended it, and I just started using it on both 914s we owned at the time. The 4.0L engine was blowing oil coolers with it, so I changed to 20W50 in it. I don't think the 50 weight makes much of a difference in the Type IV motor.

Clay
wonkipop
down here, climate maybe like texas, i'm using Penrite HPR 30 (20W-60, full zinc).
think its an aus company.

a recommended mineral oil to replace SAE 30 or 20W-50 grades we used to have.

limited sources for mineral oil these days down here.

i've just gone through the whole cold start side of my 1.8 after dramas a month ago.
confirmed everything seemed to be working properly.
its the same as usual on a cold start now, way its always been. has to idle for 2 or 3 minutes warming up before it steadies at 950 or so. then its fit to drive. before that its hopeless. motor almost dies when it comes down off some applied revs. its bone stock.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2021 Invision Power Services, Inc.