Looses RPMS When Warm (couldnt blow it up warm if i wanted)

[BRUTUS_T_HOG]

this sounds like an issue of low fuel pressure. why has nobody even mentioned checking?

you need to get a fuel pressure gauge and rule out lack of fuel pressure. your fuel filter could be clogged, you could have a bad fuel pump, or you could have other fuel related issues, this needs to be checked before you continue.

an ignition problem will cause the engine to cut out. a lack of fuel pressure will cause a sever lack of power/backfiring and extreme exhaust temperatures.

 

[vpcoded]

I will check those items soon pressure first. I have not done these due to i have no clue what in that system would faulter atfer 20 mins of driving?

 

[CraigK]

"I also thought i may have a cracked head or gastek as well due to white smoke coming from oil cap and PVC valve area and kinda sweet smell as well"

Likely cracked head?
Check oil for foam/emulsion (mix of oil & water).
Check inside of oil cap and PVC valve for "white stuff" emulsion.
Smell/observe exhaust for steam and sweetness (if you have antifreeze in).
Pull/observe plugs for fouling.
Run compression test when engine cold, then warm.

Scenario: Engine runs ~okay until warmed up, then cracks open with heat expansion and pressure in cooling system and coolant enters cylinders. Loss of compression and poor combustion due to coolant in gas/air mixture.

CraigK

 

[CraigK]

Gas tank full of rust?
Runs okay until intake of tank fuel pump clogs up, then fuel starvation?

CraigK

 

[BRUTUS_T_HOG]

I will check those items soon pressure first. I have not done these due to i have no clue what in that system would faulter atfer 20 mins of driving?

i work in a shop so i have cars with strange symptoms come in all the time. i had a similar problem with an f-150 that would run fine cold then start to faulter and die out when hot. would not start hot. let it sit for about 20minutes and it would start ok.

i replaced the fuel pump and had no problems after that, the fuel pressure was slowly dropping (had a gauge on it) and then would not pump up at all when hot.

imagine this. the fuel pump has winding of wire in it that as they age can short out, making the fuel pump weaker and then add heat which adds resistance and then the fuel pump is really weak and can't provide enough fuel pressure.

once you get a gauge you can check for this as well as a faulty fuel pressure regulator.

then we can go on from there. if its not fuel pressure then it could be a bad sensor that is "lolwut"ing the computer when it goes into closed loop. like a bad O2 sensor.

also its not very clear on what exactly is happening? is it bogging down? or is it cutting out/jerking?

 

[vpcoded]

Grabbing a Fuel press gauge today im off this weekend and have some cash hope to get something working rt. The sell stated he had the gas tank replaced no clue what that intells but will check it all out today from tank to rail. after it gets its morning atv trail run and and the crazy hill attempt.

when doing the compression test all 6 plugs looked as they should that was nice to see.

I thought a cracked head as well i put a new pve valve gromet in and the white smoke from the oil cap and pvc valve area stopped. I loose no coolant at all. Im gonna drive it to the gas station usualy shows signs of power loss then and i will do another compression test.

I have unhooked the 02 sensor and ran the truck like this before the dizz change plugs wires and still had loos of power. Dose unhooking the 02 keep it from going into closed loop ?

 

[IMenriched]

Grabbing a Fuel press gauge today im off this weekend and have some cash hope to get something working rt. The sell stated he had the gas tank replaced no clue what that intells but will check it all out today from tank to rail. after it gets its morning atv trail run and and the crazy hill attempt.

when doing the compression test all 6 plugs looked as they should that was nice to see.

I thought a cracked head as well i put a new pve valve gromet in and the white smoke from the oil cap and pvc valve area stopped. I loose no coolant at all. Im gonna drive it to the gas station usualy shows signs of power loss then and i will do another compression test.

I have unhooked the 02 sensor and ran the truck like this before the dizz change plugs wires and still had loos of power. Dose unhooking the 02 keep it from going into closed loop ?

Don't think it would keep it from going to close loop...just that it won't give accurate feed back to the ECM...er' rather the feedback will be erroneous to the extent that it wouldn't be sensing exhaust gases.

 

[vpcoded]

Ok gave it a good hard mtn climbing in front yard and a drive to the store have it running fairly shitty right now 6pm threw fuel press guage on it idle is 30 when i press the gas it climbs to 40 psi im at a 2.5 grand limit right now lol but 40 psi and it is backfireing slightly and at its power loss 2.5 grandrev limit throwing a timing light on it in just a second to see where it is now when running good with spout in and correctly timed with spout out to 12 deg BTDC it reads 40 or 50 BTDC cant rember which

 

[vpcoded]

Ok just got the timing light on it while it is running shitty.

I did this the other day when the truck was cold and running strong the timing stayed on the 40 or 50 mark while reving ect forget which one.

Just now when i did this at idle it was on the last timing mark BTDC then when revved would move farther past TDC no marks then jump down to 40 or 50 area no stable reading dose this help any one in brain storming.

I am heading back out to hit a compression reading while sick

 

[vpcoded]

Well i did a compression test while the truck was sick i did 1-3 and registered 179 cyl 1 181 cly 2 and 180 cly 3 cyls 2 and 3 were the ones i was worried about due to the soot/oil in intake man. i chose not to finish the check due to the eng being hot lol and i have a good feeling im going to come up with 3 more 180 readings. like yesterday.

 

[Robert_1967]

I’m not sure, but you have either a few wires crossed on the distributor, or some cracks in side of it, even if it’s new, you might have gotten a bad one.

Or the only thing I can think of it that maybe your timing chain jump a tooth or is badly worn, and throwing your timing off when it’s heated up.


Robert

 

[BRUTUS_T_HOG]

Ok gave it a good hard mtn climbing in front yard and a drive to the store have it running fairly shitty right now 6pm threw fuel press guage on it idle is 30 when i press the gas it climbs to 40 psi im at a 2.5 grand limit right now lol but 40 psi and it is backfireing slightly and at its power loss 2.5 grandrev limit throwing a timing light on it in just a second to see where it is now when running good with spout in and correctly timed with spout out to 12 deg BTDC it reads 40 or 50 BTDC cant rember which

good, sounds like fuel pressure is ok

40-50degrees is way too much advance.

maximum is 38-40degrees total advance.

time the ignition to 10degrees at idle with the SPOUT removed. then recheck total timing.. when you have timing that goes way advanced its a sign of the computer or TFI module going out

 

[Robert_1967]

I hadn't thought of the computer going bad, dang that's going to cost him a pretty penny to fix.


Robert

 

[xploridaho]

just went thru a similar thing with my ranger. Gas tank was rusted beyond repair and fuel injecters where plugged tight. Changed tank, filter and cleaned injecters and it runs fine now.

 

[vpcoded]

I will get a check on the timing advance when running correct again to make sure but seems like it was prob 40. I did time it to 12 deg BTDC with spout out for the base timing. I have changed the complete dizz, PIP, Ignition Mod, cap, rotor, plugs, wires, sylonid, and have been leaning towards the computer as well. I think i can find one cheap or atleast hope so. I have so much in tools and parts on this fking thing now i dont really care any more Im getting a parts truck and restoring this fker from frame to paint and getting the tools to do it all. Then turn the parts truck into the MUDD/HILL monster.

Fuel injectors were cleaned and had new rings and caps put on them. then i rewired the harnas for them .

Previous owner replaced tank thinking about cutting a access hole in my tank ha ha to get a look in there.

I just have to get somthing goning on soon for a daily driver lol. I have a parts wanted add in that area of fourms ne one has some things to sale or trade that will be ideal for my truck.