No pluse on FL injecter when car is warm, I can't seem to figure this out Options

[weird_looking_cactus]

Well I have had my car kinda running for 1 day now. I have been able to drive it up the street The car will stay going with no problems.. Then I will shut the car off and try to start it again. It turns over just fine but I can't get any pluse from the injectors. So I let the car sit for a few hours then it works fine I can even start it on the frist crank. Can someone help me trouble shoot this thanks. (IMG:style_emoticons/default/wavey.gif)

[SLITS]

Thermal breakdown of those old german microchips (ECU)?

Bad Trigger points?

Connections coroded, requiring excessive current draw when warm?

Your guess is as good as mine -
(IMG:style_emoticons/default/headbang.gif)

Your wheels are Western Wheels - there are two different styles.

[Gint]

You have rust in the bottom of your fuel tank, you pinched one of the lines again (slightly perhaps) when you re-installed the tank, your fuel pump is weak, or your fuel pressure is way too low.

Get/buy/borrow a fuel pressure gauge and test your fuel pressure.

[John]

Since others are doing it, I must chime in.....

How do you know that you aren't getting the pulses? Have you checked with a NOID light?

I would agree with Gint, it sounds more like a fuel delivery problem. You should make sure you have good fuel pressure before you jump to too many conclusions.

If you really aren't getting the pulses, it is one of a few things causing it:

A. Bad Trigger points.

B. Bad wiring / coroded terminals

C. Bad ECU (least likely)


My guess:

Bad ground connecton on top of engine case (fuel injection) causing high resistance when hot/warm preventing trigger points from "triggering". Also causing a whole host of other problems.

My recommendation:

1. Go to a car parts store and buy a can of spray contact cleaner (CRC makes a good one) or Radio Shack sells some sort of spray contact cleaner. (You could also use some very fine sandpaper to clean each terminal)

2. On your fuel injection harness...One at a time, pull a connector noting how it plugs back in, and spray both the connector and the plug with the contact cleaner and plug it back in.

3. Take your time and be sure to do each one. Some are harder to reach (like the grounds on the top of the engine case (near the transmission bell housing). Be patient and make sure they are clean. It can take a while so don't be hasty.

4. Try it out again.

Good Luck

[ChrisFoley]

I repaired a car that had an intermittent problem similar to what you describe, a year or two ago. Replacing the trigger points solved the problem.
Also, have you tested the MPS for a vacuum leak? I only mention this because same car I worked on had a bad MPS as well. The test is simple - suck on the hose that goes to the MPS after disconnecting it from the intake plenum.

[Bleyseng]

Chris, you need to test the MPS with a vacuum pump not your mouth. It should hold a 15hg vacuum without leakdown for 5 minutes. Using your mouth will only tell you if its totally gone and won't hold any vacuum. A leaking MPS will run rich, a blown MPS will run rich.

I say bad grounds so the FI can't pump fuel when its been run and then turned off.

Geoff

[Demick]

Here's my guess.

Head temperature sensor is malfunctioning. Works when cold, but goes open circuit (or shorted to ground) when it gets warm.

Test it when warm and see if you get ~ 300-1000 ohms resistance.

Demick

[Bleyseng]

It should kinda fire when warm thou even if its rich. Smell the tailpipe when this happens Catus, do you smell lots of gas? Then its this....

Geoff

[rhodyguy]

he doesn't mean stick your nose up the tail pipe and huff!!! could the cht wire be off?

kevin

[Bleyseng]

If it was I doubt that it would start and run well at all. If its shorted to ground it won't start at all.
This was the problem on the 1970 I had. When I got it (for free) the guy of course said the motors good but it just stopped running (in 1983). True enough, when I took everything apart the motor was rebuilt as a bus 1800 (woohoo 67hp) but there was the CHT welded to the engine tin. Dead short. Blair and I laughed about that one over a beer. DPO

Geoff

[weird_looking_cactus]

Im thinking its my head temperature sensor. Cause my car will start as many times as I want when its cold. But as soon as it warms up and I shut it off it. Then it won't start. It won't even start when I pour gas into the throttle body some times it will putter for a second or two. Yes I can smell gas at the tail pipe.

[weird_looking_cactus]

This is sucks my car started right up today. I took it for a run around the block let my dad take for a run around the block it ran really good. Some of my friends came over so I was going to show them how it ran but it won't start now. I looked in my manuel and couldn't find to much info on the tempertaure sensors. Im will go buy a vacuum meter today and test the MPS. Then I get some contact cleaner and start to clean all the plugs. Were is the ground for the fuel injecters at so I can go check it out.

[lapuwali]

The head temp sensor is also called Temp Sensor II. It's screwed into the head, near cylinder No. 3. Another possibility might be the cold-start injector is stuck open, or isn't switching off. This is a completely separate system, using it's own temp sensor (called a thermo-time switch or just thermoswitch. If this is bad, it can either prevent cold starts or prevent hot ones, depending on how it fails. It's supposed to only energize the cold-start injector while the engine is cranking and only when the engine is actually cold (like below 90dF). If the cold-start injector is open for warm starts, it may be way too rich to allow starting.

Temp sensor 1 measures air temp, and it's much less likely to be a problem.

Go to a Radio Shack or similar and get a handful of resistors. If you attach Temp Sensor II's wire to a 100-200ohm resistor (the exact value isn't important, just not too high or too low), and the other end of the resistor to ground, you're simulating a working CHT sensor with the engine hot. If the CHT sensor is your problem, the car will start when hot. Use a 1500-3000ohm resistor to simulate a working CHT sensor when the engine is cold. A resistor assortment is cheap, and this is an easy way to test if this sensor is the problem.

Clean every connection you can find. Bad connections are the source of 90% of electrical problems.

[weird_looking_cactus]

I think I just found my problem I unpluged the thermoswitch and then it started up.

[Rusty]

Cactus (I can't call you wierd and I don't know your first name),

Good job! You've really come a long way in the last couple of weeks. You have a right to be proud of your accomplishments! (IMG:style_emoticons/default/smilie_pokal.gif)

-Rusty (IMG:style_emoticons/default/smoke.gif)