ECT ACT no start issues

[jobei]

So, drove to work last friday, got out and tried to start the rig up and it was a no go. Ran codes and got a 21 and 24, ACT and ECT sensors. The sensors were both pretty much junk, got new ones, and the damn thing still won't start. It's turning over, I got gas and spark (pulled a plug good blue spark and smelled of gas), but it just won't catch. What the hell am I doing wrong?

Also, checked the wires to the sensors, both got a good solid 5V like they're supposed to.

[jobei]

Also so I'm giving all info, I unplugged the battery for about fifteen minutes, let it reset, and tried the start again. Got the codes again too.

[huggyb1972]

Neither of those would really keep it from running ACT will make it will make it smell like rotten eggs if memory serves correctly. Give it a shot of starting fluid If it fires off you need to look more towards the fuel system if it don't then look more at the ignition side.

[jobei]

Starting fluid seems to be a constant in what people are telling me to try. I've also read a couple of places here that the ECT will keep it from starting. What I'm concerned about is that I've fixed the problem and the codes keep coming back.

[85turdburger]

When you pulled the plug, was it wet or black and sooty?

[jobei]

Nope. Plugs look nice and healthy.

[huggyb1972]

ECT is going to help the ECM determine whether to run open or closed loop fueling I don't think it will keep from running though. So you are saying it is running but badly now and throwing codes? if you are getting good fuel pressure and the TFI is functioning correctly along with good spark it will run. That why I said try a shot of starting fluid if you have good spark/ignition system it will run if not it won't

[miesk5]

yo J,


Did you go through the Self Test for Codes yet? KOEO


And the No Start Troubleshooting, but Starter Cranks Engine in 4.9, 5.0, or 5.8L; "....TIP 1: Since a lot of folks confuse a No Crank Condition with a No Start Condition... I'll clear it up right now: In a No Start Condition means your vehicle's Starter Motor is cranking the Engine but the Engine is not starting. In a No Crank Condition, the Engine is not cranking when you turn the key to crank the Engine. This article only deals with a No Start Condition..." read more
Source: by easyautodiagnostics

Spark Tester, DIY, Long Version to use for many years (for quick test forget wires and drilling, use clamp on plugs flat sides; W/ an old spark plug and cut off the L-shaped tip,& clean up the center electrode and surrounding metal with a bit of sandpaper. Drill a small hole in the thickest part of the metal (where the socket is placed to R&R). Use a metal screw to attach a length of wire, a couple of feet, to the body of the spark plug. To the other end of the wire, solder or otherwise attach a big alligator clip. Since the tip is cut off, the spark will have to be stronger to jump the wider gap. It is harder for a spark to form in a compressed cylinder so it more accurately represents the spark performance under running conditions. With the engine off, remove the spark plug wire you wish to test from the spark plug. Attach the spark tester to the plug wire and connect the alligator clip to a good ground. Remember that the coil output can give you a very nasty shock, so make sure to wear thick gloves or use a rag to hold the tester, and not to touch the body of the car when the system is energized. Hold the tester away from the car body and use your remote starter switch or have an assistant start the car (or simply turn it over). You should get a healthy bluish white spark from the center post to the side of the spark tester. COIL; If your coil is already off the Bronco, you can bench test your coil. To set up the test, remove one spark plug wire from its plug, then remove the spark plug using a spark plug socket. Next put the spark plug back into the spark plug wire. Be careful not to let anything drop into the empty spark plug hole. Holding the plug wire with insulated pliers, find a spot on the engine that is a good and easily accessible grounding point. Pretty much any exposed metal, including the engine itself, will do. Holding the spark plug wire with your pliers, touch the threaded portion of the spark plug to the grounding point. Have somebody crank the engine with the key, and look for a bright blue spark to jump across the spark plug gap. If you see a nice, bright spark (clearly visible in daylight) your coil is doing its job.

[jobei]

Just checked fuel pressure. So that's super low. I'll report back when I'm not repairing this thing with ADD. Still trying to figure out why I can't clear my codes tho....

[jobei]

Hey, sorry to dig up this thread but I figure it would be better than starting a new one.

So I'm still getting a no start condition, and I still have codes. I've read in a ton of threads that the ECT sensor will cause a starting issue, but I've already changed it and I'm still having problems. Also, if I hear the fuel pump running and have no gas pressure I don't have a relay problem I have a pump problem, right? I don't want to keep throwing parts at this thing, and it's getting to the point I may just have to TITAFM. If anyone has any ideas I could use the help!

[TheUnforgiven]

the ECT WILL CAUSE a no start depending on how it failed.

if you have NO pressure at the rail you need to find out why. i think the 87 Bronco efi has TWO fuel pumps. One in the tank (lift pump, low pressure) and one on the frame rail (high pressure). if either fails you will not start. figure out which one has died and replace it.

[jobei]

Thank you! I just replaced the ECT and still am getting a code. I'm just wondering if I'm getting no connection between the ect and the plug. I just replaced the pump in the tank (I had to replace the tank anyway) and my next move is to replace the pump at the frame rail. Would the ECT cut fuel pressure so it wouldn't start?

[TheUnforgiven]

No, ECT tells the computer what the coolant temp is. if the sensor has failed it could be infinite resistance ( i don't remember if that means hot or cold) but if the computer things it's 1000 degrees it won't start. same if the computer thinks it's -1000 degrees.

steve83 has a graph for the accepted values and how the resistance should change with temperature. search for it through his signature, or try to google it. it's measured in ohms.

Before you waste any more time there i would verify the fuel pump that is inoperable. You can also get an ECT code during a self test if the engine isn't up to operating temperature, regardless if the sensor is bad or not. Obviously you can't get it up to operating temp without it running, so i would start with the no-start first, and since you have no fuel pressure that points to a pump.

[jobei]

Thanks unforgiven. I just had my local napa order a new pump ant it should be installed by 5 today. I'll let you know if it starts then.

[TheUnforgiven]

Did you verify power at the pump(s) before spending the $$? There may be nothing wrong with the pump(s).

[jobei]

Yep. I jumped the test connectors and verified it.

[TheUnforgiven]

[Riggs]

I just went through a very similair situation. I was getting codes like yours and no start situations at times.

my problem ended up being the computer itself. I hope your problem is that pump.

[jobei]

Riggs, me too. I really don't want to deal with a new computer....

[TheUnforgiven]

Originally Posted by jobei

Riggs, me too. I really don't want to deal with a new computer....

it's not THAT hard to change...