Engine stumbling

Slyclone

Well-known member
Re: Engine stumbling

Reset everything today. Pulled plug #1, pulled dist cap. rotated engine to TDC. re-checked the wires firing order just to be sure. ended up all firing back up but after my dad convinced me to just give it a pop of ether. I looked away he sprayed a minimal ammount and turned key it fired up. we tried to start with out but it seemed like another 2hr project trying to get it started. I spent some time and Read up on the IAC and measured it Yesterday. Thing appearntly was loose inside the housing indicating some one else was monkieing with it. So tightned it back up and felt a little more confident i would get better results.
Tried to move it again with the TCC plug on trans Disconnected. Still did the same stuff. died.
So now im a strong believer that its not the TCC plug or anything related of the such becasue this "test" failed. Still really really in the dark about it.

Oh about the starting fluid. I guess if it starts off that crap I have bad gas....
 
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milesengineer

New member
Re: Engine stumbling

have you determined if the truck is producing enough fuel pressure? you did a test on it earlier i saw and w/o vacuum it didnt move. sounds like to me you have a fuel issue somewhere. you need to verify the fp accurately.
 

Slyclone

Well-known member
Re: Engine stumbling

I dont like the quality of the gauge I borrowed from a friend. Fuel pressure was surging @ one point before on the gauge. Not sure if its a bad gauge. I just noticed how it was up and down on gauge and assumed the gauge was bad. I took vaccume line off numerious times and tried to watch the fuel pressure rise. it was so up and down on the gauge was not sure where it was at. I backed it off alot. truck smoothed out. I also purchased a cowl mount gauge and forget how it gets hooked up. Still really working on a accurrate gauge.

I do have OEM FPR that was replaced for the adjustable unit.
 

Flyin Ryan

hated cuz he drives fords
Re: Engine stumbling

You can hook the fp gauge up with the truck off then apply 12 volts to the fuel pump test connector which is by the distributor. I don't have a picture of it but there is one floating around on here becaue it's been mentioned and shown tons of times.
 

Flyin Ryan

hated cuz he drives fords
Re: Engine stumbling

Here's teh picture of the fuel pump test port I was referring to

fptestconnection.jpg


If your pump doesn't prime then it's either bad, fuel pump relay's bad or check you fp ground.
The fuel pump relay is on the pas side, next to the ic pump relay closest to pas fender in the below pic
relaymounts.jpg
 

Slyclone

Well-known member
Re: Engine stumbling

Had nothing to do with any of what I tested.

Sucessfully drove truck. Did not get a moving data-log. Did get one sitting.

Anyone got a good file(relatively good running truck) they can post up so i can compare it to my chart.
 

Slyclone

Well-known member
Re: Engine stumbling

tranny fluid.

I checked it many times.wasnt in my head but I read the manual front to back and seen something in there that kinda dawned on me. after i ran it by my dad he checked it "the right way" and told me that it was 2 qt low.

I did not believe him or it. He didnt believe it either. My last resort/ test was going to be get it up on all 4s and see if it spins. after dumping a good amount in and re-trying R-D D-R pattern it was like night and day. Took it out and I absolutely have serious low octane fuel.
 

leusgs

Member
Doubt octane has anything to do with it. If its not running smooth next step should be ignition module. They're only $40
 
Re: Engine stumbling

tranny fluid.

I checked it many times.wasnt in my head but I read the manual front to back and seen something in there that kinda dawned on me. after i ran it by my dad he checked it "the right way" and told me that it was 2 qt low.

I did not believe him or it. He didnt believe it either. My last resort/ test was going to be get it up on all 4s and see if it spins. after dumping a good amount in and re-trying R-D D-R pattern it was like night and day. Took it out and I absolutely have serious low octane fuel.

So how exactly were you checking it? Cold with the truck not running? Should be in P or N with engine running at normal operating temp.
 

Slyclone

Well-known member
Re: Engine stumbling

Yea pretty much. Disregarded the dissasembly over a year or 2 ago.(probably lost a qt there) Project sat for a good 9 mons in some one elses garage. took me just under 9 to get it where its at.

It was pretty much 1 qt low. Suprizing that much would make the diffrence. The truck did play some games with me yesterday Cat and mousing me with getting it to move but after we did more adjustments it seemed like thats how it should have been from the start. 1-2 cranks it fires. No stumbling under acceleration. Still have to assemble things like Hood, pass fender well and all the intake housing and stuff.. so im really not out on the road. I been taking it for gradual blasts down the street. enough to cycle the engine and put a good load on it. Still really havent seen any boost yet. Monitored the gauge and its comming up right above 0 but not even going in. you can hear alot of mechanical noises up front intake pulling, some what of a jet engine noise guess turbos begining to spool and than large release noises. Thing is going to need some more ringing out but im pretty sure its under control now.
 

Slyclone

Well-known member
Re: Engine stumbling

Today I was lucky to get some time to pull truck out. I came super close to wiping out my timing belt on my car and have been down for the count the past week.

My main problem this time is the truck hasnt been able to Cold start. I sit inside truck and dont hear that inital 2-3 second prime. Am I supposed to? I dont hear it. Wondering if my ffuel pump is weak or not able to send fuel up to the rail.

I have my dad assisting me with the truck. He takes off the air filter and exposed the air tube. He places his hand over the opening "choking" the engine. It begins to fire. I dont know what his theory or reasoning is but it begins to start.
It does need a blast of starting fluid to go. I dont like how that is.

Anyone know why Im not able to start truck when cold. Im thinking something with a Fuse, Relay or pump. But I dont know. I have been over the truck completely. Fine tuned the Fuel pressure again and it smoothed out. Expirencing that on-demand type of power. Before it was- Pop!-stumbling......pop-pop! Now its more of that climbing powerband I have been wating for. Just wont start. after it has been sitting for a day.
 

wildphil

I Love My Ty's
Re: Engine stumbling

When you turn the key to the run position you should hear the pump run for a couple of seconds.

If you are not hearing the fuel pump kick on. Then look at post 28 of this thread. Run a piece of wire from the lead shown to that junction on the firewall to pun 12v on that wire. This will bypass the relay. if the pump starts running you may have a bad relay. It it does not run then you either have a bad fuel pump or a wiring issue.

That relay just went bad on my truck. It goes in a out. Working then not working.
 
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Beavis

Still plays with trucks
Re: Engine stumbling

Could be a fuel filter and/or pump. You should be able to hear it when it primes.
 

Slyclone

Well-known member
Re: Engine stumbling

Now that I think a bout it I put power to that terminal before. nothing happned. What type of relay is this thing is it a typical replacment. I know the 2 up by the fire wall. The one thats closer to the intake manifold has this weird splice connector on the yellow wire and looked out of place to me right from the start. Might be the AC relay or th FP. Can I plug in the other one?
 
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