Printable Version of Topic
Click here to view this topic in its original format
914World.com _ 914World Garage _ 2.0 Djet problem
Posted by: benalishhero Mar 15 2012, 01:09 PM
Hey guys, I thought I'd pick your brains on this one. If you could knock some ideas around that would be great. I'm stuck on this one.
First off, all the baseline stuff is in order. e.g. valves, ignition, fuel pressure, vacuum etc..
The motor starts fine cold or warm, and idles fine. However it will not take gas off a stop. It will go with about 1/4 throttle if I feather it. If I punch it immediately it dies. I can also, if up to a fair speed, full throttle it(through the bog) and back it off just a bit and it will take off. Basically it's fine at idle and at full enrich. I'm suspecting a dead-spot in the TPS. 
.
Can a bad CHT cause poor acceleration?
Enjoy the day
Thomas
Posted by: Philip W. Mar 15 2012, 01:18 PM
Hey guys, I thought I'd pick your brains on this one. If you could knock some ideas around that would be great. I'm stuck on this one.
First off, all the baseline stuff is in order. e.g. valves, ignition, fuel pressure, vacuum etc..
The motor starts fine cold or warm, and idles fine. However it will not take gas off a stop. It will go with about 1/4 throttle if I feather it. If I punch it immediately it dies. I can also, if up to a fair speed, full throttle it(through the bog) and back it off just a bit and it will take off. Basically it's fine at idle and at full enrich. I suspecting a dead-spot in the TPS.
. Can a bad CHT cause poor acceleration?
Enjoy the day
Thomas
you could disconnect the TPS and see if that makes a difference, if not, check the MPS to see if it is failing. first two things i would do, easy to do, go from there.
Posted by: SUNAB914 Mar 15 2012, 01:20 PM
Philip is back? Thought he was gone after getting his Boxster!
Posted by: benalishhero Mar 15 2012, 01:21 PM
I did disconnect the TPS. No difference.
Vacuum tested MPS= fine
Tested primary and secondary coils= fine
It's got to be something simple I'm overlooking.....
Posted by: Philip W. Mar 15 2012, 01:26 PM
Philip is back? Thought he was gone after getting his Boxster!
acutually i have a spit personality- kind of - they are both mid-engine
i have not given up on my d-jet, - it is running Sweeeeeet!!!!!
it gets the jackpoint treatment beginning next week , rebuilding the tranny next month so i am still here !!!!!
Posted by: Philip W. Mar 15 2012, 01:29 PM
I did disconnect the TPS. No difference.
Vacuum tested MPS= fine
Tested primary and secondary coils= fine
It's got to be something simple I'm overlooking.....
i am thinking a blocked fuel line, maybe replace the filter. i have sounds like it is fuel starved. but i could be wrong.
Posted by: billh1963 Mar 15 2012, 01:30 PM
Philip has been shown the dark side....he likes water cooled cars. Now I'm not the only heretic in SC with a 914 and a water cooled abomination!
Posted by: Mikey914 Mar 15 2012, 01:30 PM
Sorry mis read- I was thinking it was a TPS issue myself
Posted by: benalishhero Mar 15 2012, 01:32 PM
New fuel filter
I did the re track trick. no avail
Thanks for the ideas.
Posted by: vsg914 Mar 15 2012, 01:44 PM
A little more background please. Is this a new problem? Did you do anything to it before this happened? Whats the spark at the points (open them manually with key on) and plugs looks like. Is there any sputtering when it dies, or sucking noises?
Posted by: benalishhero Mar 15 2012, 01:56 PM
A little more background please. Is this a new problem? Did you do anything to it before this happened? Whats the spark at the points (open them manually with key on) and plugs looks like. Is there any sputtering when it dies, or sucking noises?
Yes, it's a new problem. P+C are new. Gap/dwell are fine. Plugs are a nice tan color. No sputtering or sucking when it dies. Another thing, when i started it for the first time this year(few days ago) it fired right up, idled smoothly for 1min, then idled up to 2k and died. It did this a few times. I figured it was just waking up from its winter sleep. It acted like it was running out of gas. Hasn't done that since, but now the new prob. I somehow think they are related.
Posted by: underthetire Mar 15 2012, 02:03 PM
Stuck advance in the Dizzy?
Posted by: benalishhero Mar 15 2012, 02:07 PM
Stuck advance in the Dizzy?
Nice and free.
Posted by: 914_teener Mar 15 2012, 02:17 PM
Stuck advance in the Dizzy?
Nice and free.
Try swapping out to a known working ECU to elimate it.
Posted by: benalishhero Mar 15 2012, 02:30 PM
Stuck advance in the Dizzy?
Nice and free.
Try swapping out to a known working ECU to elimate it.
I was thinking that. Now where to find one in Maine
?
Posted by: tod914 Mar 15 2012, 03:10 PM
Is the contact plate on your TPS worn? What's your timing and dwell set to?
Posted by: falconfp2001 Mar 15 2012, 03:27 PM
Have you looked at the trouble shooting section here?
http://members.rennlist.com/pbanders/DJetParts.htm
Posted by: Prospectfarms Mar 17 2012, 10:02 PM
Sorry to jump in late, but I'm curious. Did the timing advance under throttle when you set is? Doing that with a light would be an easy way to double check advance plate operation.
I'd think you could tell if it's running too rich and say the plugs looked good so maybe not CHT.
No midrange can also be symptom of lean AFM. I assume this is true of d-jet. If distributor checks out, I'd get the car to idle, then start pulling FI things off-line. like the AAR, decal valve, TPS, cold start valve, temp 2, etc. Plug the vac lines as you go. Notice the RPM's and check the throttle response along the way. I've run my 1.7 with only MPS and CHT. If nothing else, you'll eliminate those circuits from suspicion. I did this a lot last year when reviving an unknown motor and it helps.
Posted by: benalishhero Mar 20 2012, 04:29 AM
Sorry to jump in late, but I'm curious. Did the timing advance under throttle when you set is? Doing that with a light would be an easy way to double check advance plate operation.
I'd think you could tell if it's running too rich and say the plugs looked good so maybe not CHT.
No midrange can also be symptom of lean AFM. I assume this is true of d-jet. If distributor checks out, I'd get the car to idle, then start pulling FI things off-line. like the AAR, decal valve, TPS, cold start valve, temp 2, etc. Plug the vac lines as you go. Notice the RPM's and check the throttle response along the way. I've run my 1.7 with only MPS and CHT. If nothing else, you'll eliminate those circuits from suspicion. I did this a lot last year when reviving an unknown motor and it helps.
Yes the timing did/does advance with the throttle.
I did set it with a light. 27 degrees btdc with bellows disconnected.
I forgot to mention that the symptoms are present hot or cold..... I guess I'm onto testing the wiring harness...
Posted by: Prospectfarms Mar 20 2012, 05:51 AM
Double check the fuel pressure first. Clamp a pressure gauge, any 1-30+ psi gauge you can get your hands on to the test nipple on fuel rail.
Posted by: Prospectfarms Mar 20 2012, 05:53 AM
What's do the Splugs look like?
Posted by: Prospectfarms Mar 20 2012, 05:54 AM
Test your fuel injectors
Posted by: Philip W. Mar 20 2012, 06:27 AM
What's do the Splugs look like?
i think he said they were tan , which could be lean running condition. .
take a picture of the plugs, post it if you can.
pw
Posted by: benalishhero Mar 20 2012, 06:31 AM
What's do the Splugs look like?
i think he said they were tan , which could be lean running condition. .
take a picture of the plugs, post it if you can.
pw
I actually pulled one this morning. No longer tan. Kind of sooty now. Let me take a pic.
Posted by: benalishhero Mar 20 2012, 06:35 AM
Ya, no need to post a pic. It's rich.
Posted by: Philip W. Mar 20 2012, 06:40 AM
Ya, no need to post a pic. It's rich.
sooty- you are right, very rich. i just delt with the same thing, that was how i got to tuning the MPS due to the super rich condition, - now i have to go back a step in the other direction- but my gas milage went from 22mph combined to 26!! so i was REALLY rich- had a badly tuned MPS it turns out.
had it re-tuned to stock setting and was too lean, so i am working my way back in in that direction. once i get my A.F. meter o2 sensor in place i will better know where i am at, - i agree with the last post, check your injectors for flow, then the cold start valve for leaking.
Posted by: rwilner Mar 20 2012, 06:53 AM
I'm in Massachusetts and I have a full 2.0L d jet system in a box -- injectors, mps, cht, brain, tps. If you'd like to "borrow" a component or 2 for troubleshooting let me know.
Rich
Posted by: Prospectfarms Mar 20 2012, 06:53 AM
Phil, if the car's not running well anyway, dirty spark plugs are only rule-outs.
Posted by: Prospectfarms Mar 20 2012, 06:59 AM
I'm in Massachusetts and I have a full 2.0L d jet system in a box -- injectors, mps, cht, brain, tps. If you'd like to "borrow" a component or 2 for troubleshooting let me know.
Rich
That's a nice thing to have and a nice offer too. I'd try a resistance test on the CHT: cold and warm. Its easy. Values are at Anders site.
Posted by: benalishhero Mar 20 2012, 07:34 AM
Well I'm back to the original problem. The car will start right up, run for a few seconds then die. After it dies I can restart it 1st crank. Man, I'm going in circles!!!
Rich: thanks for the offer. I may take you up on that.
Prospect: cold reading is 1.5Kohms. I think that out of range for an 012. Should be pushing 3kohms at room temp.
Posted by: vsg914 Mar 20 2012, 07:45 AM
The car starts on the fuel that is supplied when the key is turned on and pump is energized for a second. Then it dies when that fuel is gone. Cycle the key, and it fires again. Sounds like the pump is not running after the initial bump. Can you provide a constant source of power to the pump just to see what happens? If it runs that way, you've found your problem.
Posted by: Prospectfarms Mar 20 2012, 08:06 AM
The car starts on the fuel that is supplied when the key is turned on and pump is energized for a second. Then it dies when that fuel is gone. Cycle the key, and it fires again. Sounds like the pump is not running after the initial bump. Can you provide a constant source of power to the pump just to see what happens? If it runs that way, you've found your problem.
Curt, that's insightful, can't wait to find out.
benal...Your analysis of the 012 CHT value is correct per Anders: lower impedance may not indicate flooding, however. I was thinking that if the circuit was open it might be too rich, not that I have any personal experience diagnosing that component. It's so easy to check, so why not? I still have to wonder why your reading is off spec?
Posted by: benalishhero Mar 20 2012, 08:14 AM
Curt, I have the pump hardwired.
Prospect, I'm beginning to wonder about the CHT. In theory, a low ohms reading would enrich the system.
Posted by: vsg914 Mar 20 2012, 08:20 AM
No. A low ohm reading will lean the mixture. Thats the purpose. High ohms when cold is warm up enrichment. The cht leans out the mixture after warm up (it shows low ohms reading).
Posted by: benalishhero Mar 20 2012, 08:44 AM
No. A low ohm reading will lean the mixture. Thats the purpose. High ohms when cold is warm up enrichment. The cht leans out the mixture after warm up (it shows low ohms reading).
Ah yes k ohms. And ohms. I confuse easy.
Posted by: Prospectfarms Mar 20 2012, 11:13 AM
I'm trying to think of something smart to suggest before captain crusty yells at me. Get back late tonight.
Posted by: falconfp2001 Mar 20 2012, 01:52 PM
Curt, I have the pump hardwired.
Prospect, I'm beginning to wonder about the CHT. In theory, a low ohms reading would enrich the system.
TS2 - CHT, cylinder head temperature sensor > 2K ohms at 68 deg. F for all but 1973 2.0 L, > 1.2 K ohms for 1973 2.0L
Per http://members.rennlist.com/pbanders/DJetParts.htm
Posted by: Philip W. Mar 20 2012, 01:57 PM
I'm trying to think of something smart to suggest before captain crusty yells at me. Get back late tonight.
![popcorn[1].gif](style_emoticons/default/popcorn[1].gif)
Posted by: Tom Mar 20 2012, 06:27 PM
Sorry, couldn't resist! Just toooo funny!
Tom
Posted by: 2xs performance Mar 20 2012, 06:30 PM
This may or may not apply...
I have a 2.0 d-jet. hardwired fuel pump. It would run great for just a couple mins. then would not take any gas above a idle. Idle fine but nothing if I gave it gas. I put a gauge on it. fuel pressure dropped to as low as 8 psi when given gas and was very very slow to build back up.
I just bought a new pump today. Should be here in a couple days.
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)