my buddy has a 97 mountaineer with a 5.0, around 170k miles. has needed nothing but gas and a wheel bearing since i bought it for him 13 or so months ago.
the other day it stopped running at the gas station near his house. then said it would not crank. he got a jump and made it home, installed an alternator assuming the battery was not charging, charged the battery, and got a no start/slow crank condition after all this was done.
i popped the belt off and found the ac compressor locked up. i hoped that it would just start, so we tried it and got nowhere fast.
first test was starting fluid. no start. it didn't sound like it wanted to even.
second test was spark. strong spark on all 8 cylinders.
third test was noid light on injector plug. good on all 8.
fourth was fuel pressure. 37psi at key on. the interwebs says 35-40.
so we have pressure, pulse, and spark, but no fire.
i conclude it probably is not sparking at the right time if it doesn't want to fire with both fuel and spark. could this be attributed to a faulty cam position sensor? or would an abrupt stoppage of the engine from the compressor locking up possibly have caused it to jump time?
he's borrowing a pickup from his dad for the time being but the mountaineer needs back in service because it's the safe ride with a back seat for his 4 year old. he's also buried in bills and heading for a custody battle so buying something else is not in the cards.
any help is greatly appreciated.
First check that the injectors have ground. The next thing is to check for air. If it has a sensor where the distributor would be pull that and make sure things are turning. If the crank is turning, then check valve timing.
it would not fire on ether with the throttle plate cracked open and the intake boots off, so i think that rules out a fueling problem.
the crank is turning. if the (cam position?) sensor that replaced the distributor was not turning there would be no spark and no call for injector pulse, no? it has the coil packs front and center above where the once distributor would have been on an older 5.0
Nashco
UberDork
3/8/14 10:03 a.m.
All that's left to check is timing and compression...if you have some fuel, correctly timed spark, and compression, stuff explodes. Check compression, which can indicate multiple problems and is an easy check. Then find TDC and make sure stuff lines up as expected.
Bryce
Some systems use a crank position sensor and a cam position sensor. If your doesn't then disregard.
awesome. my heroin addict cousin blew up my compression tester and himself in his parents' barn last year trying to test a tacoma with a fuel leak. he lived, nothing else did. it was most unfortunate.
time to get a new tester.
AngryCorvair wrote:
patgizz wrote:
time to get a new cousin.
FTFY
dbag's in prison again, i'm done for good.
anyway - could the abrupt stoppage of the engine from the compressor locking up cause a relatively high mile engine to jump the timing chain? because i've seen some pretty sloppy timing chains in engines with less miles.
patgizz wrote:
i conclude it probably is not sparking at the right time if it doesn't want to fire with both fuel and spark. could this be attributed to a faulty cam position sensor? or would an abrupt stoppage of the engine from the compressor locking up possibly have caused it to jump time?
Yes, it could be faulty CMps. If it doesn't know where the cam is, its guessing.
As far as jumping time? Not likely. A timing chain like that one usually gives you ample warning, and even if you ignore the warnings for three years, chances are it will break long before it jumps time. It is also almost impossible for the A/C compressor to stop the engine, and the belt would break long before it did any damage to the engine.
Put a timing light on it? Have you scanned it?
no we were just going through the easy steps. it's at his house, he has no tools, i took what i could grab and worked with a sleeping 2 year old in the truck.
i have a crude harbor freight code scanner. too bad hptuners doesn't work with it.
i have a bluetooth obd2 scanner, wonder if i can get an app for my iphone to use that.
idea. can cam sensor be tested with timing light? like put it on #1 and shoot the balancer to see if the mark is anywhere near the timing tab? or did ford drop the timing marks when they went distributorless?
bear in mind my only ford experience is having owned a 5.0 vic, a couple 4.6 vics, and parting out a mark vii so i don't know a ton about their workings. if i was diagnosing an ls1 or tpi small block i'd have had it running already.
we definitely can't afford to start throwing parts around, as he's in a tight spot as it is.
I doubt it doesn't have timing marks, if not it'd be pretty simple to find TDC (roughly) on #1 with a pencil and draw a line on the balance on timing chain cover.
