88 351w compression results

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Mar 18, 2011 | 04:50 PM

#16

doinfroggy

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i guess i am gonna look in the bottom end

Mar 18, 2011 | 06:02 PM

#17

lew52

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Well 160 -140 is about normal , 130 is a little low but should be ok , what problem are you having with the truck.....On the ones that are high , im with oldman , carbon build up , probabley will be on the pistons , the first test you did they were 145 ??

Mar 18, 2011 | 06:33 PM

#18

doinfroggy

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https://www.ford-trucks.com/forums/1...-problems.html this is the link to my other post. a detail write up on the problems of the truck. just yanked out the cam as well. on the 3 and 7 lobes you can see pitss and wear on the max lift of the lobe. i will take pictures and attempt to upload them here in a few. trying to get the oil off and not tell the wife i am cleaning them in the tub

Mar 18, 2011 | 06:53 PM

#19

White 97 xlt

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From: Cleveland, TN

Well compression WAS NOT the cause of you original missing and shaking (IF your reading are right).. Put the darn thing back together and look for the REAL problem!!!

Now if you have money to waste getting all 8 cylinders with one pound of each other, go ahead and knock yourself out.... But it will not cure the original problem...

Mar 18, 2011 | 07:00 PM

#20

doinfroggy

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well if you read the 2nd set of compresson numbers, there are 2 cylinders that are well below 20%. the reason i did the compression check is to see if i could pin point which cylinder(s) that might have an outstanding problem. cylinder 3 and 7 are wwell below spec. the main problem is too low vacuum which is causing the nasty shake.

according to the wet compression test, it was pin pointed in the valve area which also could cause low vacuum. as for the money, this is just tax money i have put back to get my truck as perfect as i can. i have none to throw around. Plus i love working on vehicles.

Mar 18, 2011 | 07:01 PM

#21

lew52

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After reading that thread , with the low engine vacuum , look at the cam timing , timing chain , you took the cover off but don't remember what you did ???...Good luck

Mar 18, 2011 | 07:13 PM

#22

doinfroggy

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i broke the timin chain cover on the running motor. took it off the doner block and noticed it had a double roller chain on it. took the peices of the cover off the good motor and noticed it had a double roller timing chain on it. for some reason i kept thinking i took off the chain on the good motor. i had no reason to and i dont think i did take it of, but 3 monoths ago was a long time. there is slop in the chain, more than 1/2 in if you squeeze it. i just gonna buy a new one so i can set my mind at ease. might have enough in the budget for a new cam too. hmmmmmm

Mar 18, 2011 | 07:35 PM

#23

lew52

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Way to much slack . There should be no slop in the chain , the timing marks on the gears need to line up , cam mark at 6 oclock , crank mark at 12 oclock ,,,,Thats your problem....