87 2.9 low fuel pressure KOEO

[wingzam]

No had to work today.However got a tip from a friend that an air leak thru the throttle shaft could be causing the problem.There's some small play there.Will give it a spray and see what happens tomorrow and give an update.Thanks for checking back 52!

 

[wingzam]

I checked to see if there was any leakage around the throttle shaft.Like I said there is a little play,very little but no reaction to throttle body cleaner.Have seen a number of these engines with intake manifolds leaking oil at the front and rear.Could this be causing a vacuum leak or create a condition that would cause the surging/hesitation?It's on the list of things to do and I suppose sooner rather than later.Tomorrow - more troubleshooting.

 

[IMenriched]

have you cleaned the AIC yet??
seem to be a vacuum leak yet....??
How does the brakes feel?? if in the past there has been a FPR that was leaking ...this could, in theory, get gas into the booster for the brakes and eat at the seal within the booster itself. causing a leak .

if you have a vacuum gauge available and a buddy. get it running with vacuum gauge on & have someone pump the brakes see if vacuum drops significantly

 

[wingzam]

have you cleaned the AIC yet??
seem to be a vacuum leak yet....??
How does the brakes feel?? if in the past there has been a FPR that was leaking ...this could, in theory, get gas into the booster for the brakes and eat at the seal within the booster itself. causing a leak .

if you have a vacuum gauge available and a buddy. get it running with vacuum gauge on & have someone pump the brakes see if vacuum drops significantly

The AIC is pretty new and not much build-up in the intake to suspect this as the problem.Went thru the vac systems and found no leaks or evidence of fuel going to the booster.It's been awhile since I put a vac gauge on it,but have checked whatever the readings were against the recommended troubleshooting suggestions.Ran pressure checks on the fuel regulator.didn't hit good numbers till the vehicle warmed up,but is within spec,if a little on the lean side at 30psi.As before,when I remove vac from regulator it goes to 40psi with just a bit more roughness.don't know what to think...
Hate to say it but am breaking down and taking it to another mechanic..."third times the charm" they say...little faith in that and even less confidents in mechanics,but i'm about at the end of what I can do...i'm flummoxed!

 

[wingzam]

I did put in the other MAP sensor - no change.Had a friend look at it this past weekend.Started it from cold,he pointed out how the IAC valve was working too much to correct what he thought was a vac leak.The idle was going from low to high a number of times until it settled down to an even RPM.Had this to a mechanic 6 months before who said this activity was normal,which is why I hadn't mentioned it till now.I've been thru this vac system and found nothing,which is the reason for my question about the leaking intake manifold.Everyone i've talked to says no,anyones experience different?

 

[dirtymike]

damn skippy on the 6 bolts VS dropping the tank.

 

[dirtymike]

sounds like a TPS not set to proper voltage. voltage at KOEO is .85 to 1 volt, center wire on tps to gnd.

 

[wingzam]

It's been awhile since last here.Have changed the fuel pump,changed the intake manifold gasket,and I must say this is the best running,crappy running engine i've ever had!Starts immediately,hauls butt,still misses!

Perhaps i'll start a new thread,but maybe someone can give me a few tips from here.

Hesitation is present from start up,but as it warms up it will start to suck a dollar bill to the exhaust pipe..

Have heard that the distributor could be causing the hesitation..something in the housing itself.A glitch in the manufacturing,and the complete distributor needs to be replaced.

Had thought the progressive hesitation could be the valves out of adjustment.when I replaced the valve stem seals I turned down the lash to spec.No difference though.

Wonder if a worn cam lobe could be the answer here.Sure hate to pull the dern thing apart to find out though.