74 2.0 FI - I am stuck, My 2.0 is running only when cold for 2 minutes Options

[Larouex]

Hi,

I have been lurking for a while and I am stuck, so I wanted to reach out and see if anyone can help me.

Symptoms
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1 - Car starts when cold
2 - Runs for a few minutes
3 - Then I start to see white smoke
4 - Then it dies until cold again
repeat 2-4

What I have done
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Replaced all vacuum hoses with new one from AA. Verified all is correct
Tested injectors and replaced one bad one
Tested spark at plugs, seems inconsistent
Checked points gapped correctly
Checked distributer
Checked the injection trigger points
Replaced cap, rotor, condensor and plug wires

I picked this car up in an estate sale and it is really good shape (a little rust in the treated hell hole and some surface rust), but this is a real barn car.

I have tried to check out all that I am capable of and according to other tech articles, it says to check the triggers, but injection seems to be operating. I tested by pullling injectors and testing the flow. I have not checked fuel pressure yet.

Once it dies, it really will need to sit and get cold, then it fires up. Teases me badly <g/>

Let me know your thoughts to t-shoot this better, I want to solve it, the family is watching me <g/>.

Larryj

[Spoke]

The one thing I can think of that senses temp is the cylinder heat temp sender. Check this item out. It is located above the intake for #3. Should measure about 2500 ohms cold and something less than that warm. Measure from connector to engine case.

[jc914]

I have to (IMG:style_emoticons/default/agree.gif) You have checked many things but the CHT sensor. Does the car idle fine when its running

[Larouex]

I have to (IMG:style_emoticons/default/agree.gif) You have checked many things but the CHT sensor. Does the car idle fine when its running

I am unable to get the car to run more than a minute or so. I will check the CHT when I get a chance and I checked the documentation @ pbanders t-shooting on measuring that.

There is a little history in CYL 3 as that was the one with a malfunctioning injector and when I first started it, it blew white smoke up the comparment. I will need to get a better look at this area and see if it stripped, etc.

[wilchek]

a quick way to check the head temp sensor is to pull the line and ground the line right to the body. At full heated temp it is all but a gournd. However, it seems unlikely that the car would heat up this quick 2-3 minutes is really quick.

What you need to find out is the car flooding out. Which I would guess it is. One way to figure this out is to pull the relay for the fuel pump. After the car dies open your engine pay and locate the relay board on the drive side (take the cover off). After it dies on you pull the round black relay on the outside of the board farthest away from the 2 color fuses (hard to explain without a picture). Then turn the engine over and my bet is that it will start after a bit a cranking and run for about 5-15 seconds.


ALSO a question. When you run it when it is cold how does it run??

Next step would be to clean all the grounds at the base of the intake under the aircleaner. Also possible that the fuel return line is blocked a bit and is increasing fuel pressure too much and causing the injectors to leak and eventually flood out engine. However, it seems a bit odd as temperature may be the issues but it may just be the pressure is building for the first couple of minutes and then it bleeds off as time passes and the fuel evaporates. So it may just be flooding. I had a similar issues and everyone kept telling me it was not the computer. However, it ended up being the computer. It is really easy to change the computer as it has a quick conncection.

[r_towle]

(IMG:style_emoticons/default/agree.gif)

I would suggest a different idea for the issue.

The cold start injector is stuck open.
Test that injector to ensure it shuts off...sounds like its staying open.

Rich

[wilchek]

Could be cold start, it is on the throttle body under the aircleaner. It is actually just another injector. It should not activate unless under 32 degrees.

Check this forum out from earlier this is what I posted for a similar problem
http://www.914world.com/bbs2/index.php?sho...c=86659&hl=

First, I think you need to narrow down your search and work on one area at a time. First check the fuel pressure with a pressure meter. Harbor freight has them cheap and it will be fine for this purpose. To me it seems that you are thinking much worse than it is. Make sure the head temp sensor is good. IF you are flooding out which you are you should be able to remove the temp sensor and ground the line to the body and this will run at a fully heated setting (more lean). If the car still floods out then it is not the head temp sensor (sounds like this is not the issues). It sounds like one of you injectors are stuck open and the car is running for 30 seconds due to running out all of the fuel that is in the chamber. I think it is running with the MPS disconnected as there is still fuel in the cylinder. The injector can be stuck or the fuel pressure is too high causing the injector to leak. If the pressure is too high replace the pressure regulator, and make sure the return line to the fuel tank is not clogged. If these areas check out make sure the fuel injectors are not stuck open. So now we ruled out MPS, head temp snesor, fuel pressure and injectors. Last think to look at is the wiring. Clean all the contact at the board (which you did) and the ground contact under the airfilter at the base of the intake (all white lines). If this does not work I would bet it is the computer. I know they say that they never go but this is not true. swap a new ECU out with the quick connector under the grey door on the side of the ECU and go.

Steps to check

1. MPS ( sounds good)
2. Head temp sensor and wiring (sounds good)
3. Fuel Pressure (issues could be pressure regualtor, return line, fuel pump,and stuck open injector)
4. Injectors (stuck open)
5. ECU
6. Ground wiring

One of these things above is causing your car to flood out.

[Larouex]

Great, plenty of solid stuff to go through, I appreciate it. I am sure to go though each item one by one and test.

I did replace the MPS (as the one on the car from the PO was hacked from some other car/engine and had the open adjust screw).

I ordered up a Fuel Injection pressure tester from HF, thanks for that, I was procrastinating, but I need it anyway as I want to put on bigger fuels rails when I am up and running.

I will report back mid-week.

[Root_Werks]

(IMG:style_emoticons/default/agree.gif)

I would suggest a different idea for the issue.

The cold start injector is stuck open.
Test that injector to ensure it shuts off...sounds like its staying open.

Rich

Unplug it, it'll run a little rough when cold but it'll run and stay running. Commong prob on CIS 911's.

[Root_Werks]

Where you at? There are local guys that could come out and take a look. I'm up North around Lake Stevens.

-Dan

[Larouex]

Where you at? There are local guys that could come out and take a look. I'm up North around Lake Stevens.

-Dan

Nice offer, I am in south Seattle near SeaTac airport and usually work on the weekends on my projects.

This is my GAS car, I am also doing a EV conversation and about a 1/3 of the way through my rustoration.

Larry 914 EV Project
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http://larryj.spaces.live.com/?_c11_BlogPa...%2bEV%2bProject