A few questions regarding my 87

[Jared's 87]

Originally Posted by spinem

bad diaphram is brake booster will kill engine when brakes are depressed.

sloppy idle=vacc leak &/or going bad/bad egr?...most likely vacc.

Do u have to "put ur foot in it" to get up to a decent speed?

Vac lines are new as well...EGR not sure

Driving down the road its fine, its the sitting at a redlight part when it has trouble

[motornut]

ac pics from 89

[Jared's 87]

Thanks fo the pics, but mine is a little different....






This is the connector that I think goes to the compressor..

[spinem]

Originally Posted by dammitmitchell

checking it in neutral or park you dont have anything but the brakes to worry about, if it's dying during deceleration there's a tons of other things to think of.
for example (this just happened to me)
while sittin in the cab ready to back out the truck would be warmed up and ready to go, depress the brakes and sputter sputter dead...
and there's this like throaty hiss inside the cab when it happens.
but either way if you disconnect the booster vaccum then do a short drive and the motor still keeps quitting out, it's definatley not the booster..

im all aobut isolating things one at a time, because my brain gets all cluttered i look around and go "shiny" and forget what i was doing

[spinem]

Originally Posted by Jared's 87

Vac lines are new as well...EGR not sure

Driving down the road its fine, its the sitting at a redlight part when it has trouble

correct. if its a bad booster diaphragm it will die when brakes are depressed... usually at stops, and eventually while driving.

vacuum is not just lines, its carb gaskets, its manifold gaskets, even valve cover gaskets!... id check that egr... spray wd-40 or carb cleaner around everything that has to do /w/vacc. (with vacuum to distributor disconnected...very important) if the idle gose up where u sprayed it... BAM! THATS THE LEAK.

[Jared's 87]

Ok, I am gonna check the vac system next, thanks

[Alias137]

Here is a thread I started on a factory tach. To make a long story short, I didn't change anything regarding the pins. I used my stock cluster, and ran a shielded wire from where the fuel gauge was to where it is now. Hope the link helps. If not, p.m. me, and I can tell you exactly what I did. BTW, I have an 86 with a vss too. My regret was that I forgot to re-install the cruise sensor, now I have to take the whole f*&%ing thing apart again.
factory tach/100mph speedo ( 1 2)

I can't figure out how to do the link thing, but that is the thread title.

[Jared's 87]

Thanks, I will take a look...

[Jared's 87]

Noticed a couple of intake bolts were not tight and causing a whistle, fixed that. Timing great, checked all vac points including the booster w/ some brakeclean to no avail. Disconnected and capped off EGR connection, didnt help. Decided to turn up the idle a bit (I know I probably shouldnt have, but its helping for now). It still bogs down a good bit when put into a drive gear w/ brakes applies, but I also notice hesitation when I hit the gas (dunno why thats happening). Thats pretty much where I am at this point....Do I need to drive it around for a couple hours letting the throttle out to clean it out? Another seafoam treatment in order? Suggestions....

[87 STEPPER]

Im worndering now if you may have a bad fuel pressure regulator diaphragm or spring this will cause those type problems.It's located between housing #3 and #7 it's the red rubber part in the gasket set pic.

You may want to pull it apart an see if its ruptured also if you pull the injectors out there is a small screen #11 in the diagram those can get clogged up with debris as well

[dammitmitchell]

so iv been gone for a few days..
any progress?

[Jared's 87]

Originally Posted by dammitmitchell

so iv been gone for a few days..
any progress?

Decided to take the weekend off from everything, including the truck. I forgot to mention that I did disconnect the injectors one at a time and it did kill, and I also disconnected the MAP (just to check) and it ran like total crap. Hopefully, gonna borrow a fuel pressure tester from a friend, just to see if I have proper pressure. The hesitation when I hit the gas in a drive gear has got me wondering now. Whats the best way to check pressure on these, put a T of some sort right onto the TBI I guess?

[dammitmitchell]

if the intake bolts were loose ad it was givign you a "whistle".. you might need to redo the intake gaskets first..

[Jared's 87]

Probably will replace the gasket, just been tied up at work lately. Just doing the simple things for now, gonna be moving my shop to FL in the next couple weeks, so truck may have to be on the back burner, its not my DD anyway. Just wanted it running good enough to do some beach cruising in FL, but will probably start tearing it down and make sure all is done right. I will still check the fuel pressure just in case, and then will most likely shut down progress on it for at least a month or so, so I can get my shop set up.

[Jared's 87]

Just a quick update. Dropped it off to my mechanic last Monday, and as of right now, he doesnt know whats going on either. He told me timing is on, fuel pressure is good, and hasnt come across any vac leaks either. His words "this truck has me really scratching my head". He said next he will take the ignition module off and have it tested (which btw looks new). He told me possibly the computer on it may be going bad, dunno. He does strongly feel its something electronic, but who am I to second guess. He also mentioned that possibly when the ignition module gets hot, I may not be sending proper voltage (correct me if I'm wrong) to the injectors. Thus the reason he is taking it off and having it tested. He said the injectors pulsate correctly, but who knows. He also mentioned if it was his truck, he would swap to a carb and be done with it.

But, I guess the bright side is, while at his shop, he mentioned 3-4 folks pulled in asking if it was for sale. So maybe I should............................Most likely not though