running rough? lean?, suggestions or answers? Options

[mipstien]

ok so i get my haynes manual soon and i have been searching but don't have all the information in the same place and i also don't know all of the shorthands yet. AAR CHTS etc etc. which brings me to my question

tomorrow i will have a fuel pressure tester and need to know what all the different pressure's need to be at all the spots.

basically if we give it extra fuel at the intake it idles fine and as soon as you stop and the fuel runs out from there it goes back to really rough again. we have a handful of other things to check also so any suggestions?

one other thing that makes me think its running lean is when i rev the car and hold the peddle in one place it begins to drop revs unless we add our own fuel into the intake. once we add fuel the car runs very smooth.

so any ideas and fuel pressure numbers and where to check it?
thanks
ryan

PS- its a 75 2.0l

[underthetire]

D-jet, L-jet, carbs, ???

Think we'll need more details.

[mipstien]

best i can tell you now is that it is FI but i don't know if its djet or ljet because i don't know how to tell.

[underthetire]

Makes a big difference. Take pics and post. You will get an answer in minutes. As far as the"slang" try this
http://www.914world.com/bbs2/index.php?showtopic=13766

[mipstien]

http://www.914world.com/bbs2/index.php?sho...=104530&hl=

that is the car. old picture but looks the same still.

[SLITS]

If it's a '75 2.0L, it's D-Jet.

[mipstien]

If it's a '75 2.0L, it's D-Jet.

Ty

[underthetire]

2.0 should have a Djet. Fuel pressure should be about 29 PSI at the injector rail. Should not drop with throttle.

Other culprits, bad fuel filter, clogged fuel sock in the tank, bad or miss adjusted throttle switch among others. My bet would be on fuel delivery.

[mtndawg]

Trigger points?

[realred914]

ok it is a D-jet 2.0 liter he says it runs lean, could be several things


lets check.

fuel pressure should be about 28-29 psi measure it at one of the two fuel rails, there should be a test port on one rail.


head temperature sendor (very likely culprit) this is near cylnder #3 it changes ohms when it heats up, and command the computer (brain) to give more fuel when cold, less when hot. if you remove the wire to it, you may then ohm test it to ground (ohm test the pig tail wire to the sendor, NOT the wire that goes back to the brain!!!!!) cold, the head temp sendor should be a couple thousand ohms, when fully warmed up, it should be less than 100 ohms. also wiggle the wire vigrusly when you do the test, often the wire breaks, or the insulation tears and you get intermittant opens or shorts. if you got an open, the system will give too much fuel and flood, if you got a short, the system will not give enough fuel to keep her running while cold.

Trigger points, these are under the distributor and are a pair of points, they trigger the injection pulses. there is a three wire connector that goes to them on the dizzie base, make sure the wires is good. the points are hard to test, pull the dizzie and by rotating and with an ohm meter you should be able to tell if they make contact of not. they can fail by being dirty and not making contact (no fuel then) or they can have a worn lifter and that will cuase them to not open far enought and hence bouncem, thus givving multible trigger pulses and hence too much fuel (rich running)

the pressure sendor n make sure it is wired intact (inspect the plug carfully for torn wires) make sure the vacuum hose to the sendor is leak free, and suck on the hose to make sure the sendor does not leak.


good luck my bet is ont he head temp sendor simply cuase I have found them to fail most often, so test that first it is also the eaisist to test of the bunch.


good luck!!! (IMG:style_emoticons/default/driving.gif) (IMG:style_emoticons/default/driving-girl.gif) (IMG:style_emoticons/default/chowtime.gif) (IMG:style_emoticons/default/chair.gif) (IMG:style_emoticons/default/beer3.gif) (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beer.gif) (IMG:style_emoticons/default/smilie_pokal.gif) (IMG:style_emoticons/default/screwy.gif) (IMG:style_emoticons/default/smash.gif) (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/santa_smiley.gif) (IMG:style_emoticons/default/icon8.gif)

[mipstien]

well after playing with her for a couple of days we pulled plugs on the passenger side and found that one was wet and one didn't seem to be getting fuel. so it seems i may have been firing only 2 cylinders. so we have gotten some new spark plugs, although not boshe plugs its a matter of testing and what we have access to at 12pm at night. after changing the plugs it did run a little bit less 'bouncy' or 'jerky' but it still didn't idle.
the head temperature sendor seems like it may not be running either because we have 0 resistance ( i think) from the plug/nipple when unhooked. the one injector that didn't seem to be shooting any fuel but was still clicking along. probably clogged.

how do you go about cleaning one without sending it off for now. i'd prefer to check these injectors and get them doing at least something before i send them all off to find that the injectors aren't even the issue of my bad idle.

where can i order a head temperature sendor? the wire on it is pretty rough too which will be replaced/repaired when we get the other unit.

is there an good place to get a new wiring harness for one of these things or should we go about making a new one ourselves?

[mipstien]

http://tinyurl.com/2aosbuv
or
http://tinyurl.com/32c6qmy

are either of those the same thing?


also after looking at those things, mine doesn't have a pigtail like that?????? it seems to be a single wire with a blade plug comming straight up. starting to think i was looking at the wrong thing.

[mipstien]

Easier to reply from phone than edit.

Took a quick look and I think the thing we shoulda looked at iks under the air tuube and above the injector? Correct?

So what is the piece just forward of cylinder 4?

[poorsche914]

If you think it will help, come by and grab that extra ECU and harness. A lot of the wires are hard/cracked but still some useable ones.
That's odd about the wet plug and the one looking like it isn't firing. I pulled the plugs a couple times and they all looked good. (IMG:style_emoticons/default/confused24.gif)

[mipstien]

Well right now those 2 pllugs look like they are gapped very small and have a lot of carbon build up

[mipstien]

so I got to thinking about that sensor part and wasn't sure if this makes any sense but in theory if you unplug it and turn the car on wouldn't it have 100% resistance and it woulld act as if the car was cold? And if unplugged and grounded would act as if the car was warm/hot?

[mipstien]

bump?

[detoxcowboy]

for your cylinder head temp purchase

http://www.pelicanparts.com/cgi-bin/ksearc...1-906-041-A-M14

for understanding and check list order of going through the djet

http://www.rennlist.com/techarticles/djetronicfuel.htm

for trouble shooting your djet.. keep reading and doing till you get it, when you do it becomes the core to getting a grasp your car problems

http://members.rennlist.com/pbanders/DJetParts.htm

a bit further on idle stability and how is it supposed to run anyways

http://members.rennlist.com/pbanders/idle.htm

keep posting..

[detoxcowboy]

i thnk i read bucking and jerking in one of your posts, is this a steady part throttle like cruising a parking lot or down a suburb nieghboorhood.. (throttle position sensor)

starting at the end of part load to full load like getting on a freeway and trying to hit and maintain 60mph ( manifold pressure sensor)

these are not absolute answers but my owqn recent exp[erience and working solution..

[mipstien]

im just working on a idle problem driving seems fine