87 5.0 won't start - ignition ok, fuel pump ok

[dsblk93gt]

If you get phenolic spacer that blocks the EGR you can unhook the hoses, if not leave them on. Otherwise, unhook them and see how hot the EGR plate gets!!!

I always used the EGR block off spacer on my 5.0's and the intake stays much cooler. No real "gain" but more consistent times. I used to try anything and everything.

 

[mmp142965]

Hey guys,

I checked the compression, all cylinders close to 150psi. I changed the spark plugs and now it runs better and idles. Changed the ACT as well. Still dumps black smoke so I'm going to check the vac lines to the MAP sensor next.

Still not sure if it is a reverse rotation water pump or not. I don't really know how to check that but maybe ill just pull the rad hose off and see how much coolant pumps out. Thanks again!

 

[mmp142965]

Well, I checked the vac lines and they seem to be ok. Also there is no vac leak noise around the engine except for the front of the throttle body. Also when it first starts up it makes some light white smoke out of both tail pipes and doesn't seem to be as black now. I unplugged the MAP sensor and it seemed to run just the same as when it was plugged in on idle. Is that normal? Maybe the MAP is bad. Also, I'm going to have to check the ignition at each plug because its still not running on all 8 cylinders.

 

[TheWhiteFox]

Well, I checked the vac lines and they seem to be ok. Also there is no vac leak noise around the engine except for the front of the throttle body. Also when it first starts up it makes some light white smoke out of both tail pipes and doesn't seem to be as black now. I unplugged the MAP sensor and it seemed to run just the same as when it was plugged in on idle. Is that normal? Maybe the MAP is bad. Also, I'm going to have to check the ignition at each plug because its still not running on all 8 cylinders.

people do crazy things when they build these cars, try both firing orders (H.O & non H.O) just to make sure, I had a friend bring me a car and it was a fuel injected 87 but the motor come to find out was out of an 83 with the 83 cam in it :smash: so just to be safe

 

[dsblk93gt]

people do crazy things when they build these cars, try both firing orders (H.O & non H.O) just to make sure, I had a friend bring me a car and it was a fuel injected 87 but the motor come to find out was out of an 83 with the 83 cam in it :smash: so just to be safe

Or a motor from a F150/Lincoln/Crown Vic/etc.

The problem is, even if you get the firing order right, the injectors are sequential so it will not run right. One of my friends found that out the hard way and had his motor backfire so bad it drove the camshaft into the timing cover, broke the distributor, etc.

But I'm thinking it is an HO motor because it does run. But someone may have it wired as a non-ho.

 

[mmp142965]

Oh ok thanks! I found another thread that has the 2 firing orders, ill print that out and check tonight.

 

[mmp142965]

just checked the firing order, it is correct for HO. :smash:

 

[toomanytoys]

You changed the plugs but the car still isnt hitting on all 8 cylinders? Are you sure ? If so just pull one wire at a time while the car is running and when you get to the one thats not firing there wont be any change in the way the car idles. A bad cap, coil, wires etc would also explain the black smoke (unburned fuel) in the exhaust. Hit that car with a FULL tune up.

 

[dsblk93gt]

Could have a bad injector. MAKE sure the HEGO ground is connected, orange wire that grounds to the head.

 

[TheWhiteFox]

yeah the one I had dropped off to me was the same set up, and that ran and drove, but still would break up and, had a hard time idling so I guess you never know

 

[mmp142965]

Hey guys, I did some more tests and found a few more things out but its still not running very well. I changed the plugs, cap, rotor, and wires and definitely gets better spark. Checked TDC, checked that the dist isn't 180 degrees off, fuel pressure is good, injectors dont leak, and the ign timing is close...going to get a timing light on it this week...

Also checked the vacuum... running around 10 inches. I'm told it should be around 20. Obviously this is why its running so rich, but I cant figure out the vacuum problem. there are no apparent leaks and all unnessasery lines were plugged. Engine also has good compression. With the exeption of a different cam (which I dont know how to tell what cam is in there) is there anything else that would cause the low vacuum? Maybe the lower intake manifold is leaking? The upper and all vac lines seem quiet.

Thanks guys!

 

[toomanytoys]

Check the map sensor. If the little diaphram inside popped it would cause a vacuum leak.

 

[Goeasy]

This sounds like the same issues I had with my 88. I ended up replacing all of the sensors. Then I had to pin check every wire on the wiring harness. It turns out that I had bad wires and the supply voltage was low on one sensor and the return voltage was incorrect (it had crossed over to another wire) on another sensor. Apparently grounding is very important on these ecu's also. Had to add a ground right at the ecu. All of these problems led to the pulse width on the injectors to be about 2.5X what they were supposed to be. This, in turn loaded up the oil with gas. I had to change the oil after about 15 minutes each time I fired the car to check progress. If I had it to do all over again, I would have replaced the main wiring harness in the begining and saved about a months worth of work. Good luck and I hope you find the problems easier than I did.