87 TBI

[GT1000000]

 :'(hERE i SIT bROKEN hEARTED, cAME TO SH.....
Hey guys,
I am truly suffering...Got an 87 V-20, 5.7L TBI 4X4. Laundry list of parts,
anyhow, here's my story; Came home runnin fine,went to start,nothing but rich black smoke, mixed with antifreeze...first thought,computer problem? Break out the scanner,nothing wrong...Check compression, all eight between 180-190 psi, check the radiator and sure enough...bubbles,millions of them...possibly blown head gasket or cracked head? Well decided to be ready for the worst possibility and decided to go whole hog...Crane cam,Trick flow heads,Roller rockers,Adjustable fuel regulator,New lifters and pushrods,plus all new Fel-pro gaskets... took everything apart and found the intake gasket sucking coolant and oil in through both back cylinders and the valve seals on 5 out of 8 cylinders cooked[must have occured about a week before when I ran very low on coolant and quite possibly overheated, honestly I just filled it up and kept going... So here I am having just spent a couple of weeks of evenings after work installing all these nice new goodies and when I finally get it running and break in the cam, it just won't idle. Let me try to explain, if I start it and immediately rev it a bit I can almost keep it running...If I disconnect the MAP vacuum, it will sort of idle for a while and then cuts off,although with the MAP disconnected it is very hard to start. On with the scanner again and after I clear the codes[by disconnecting the battery] I start it, rev it, keep it sort of running , for a little while[5-30 seconds],and let it shut off,there are NO codes...
I have adjusted the fuel pressure from one extreme to the other, re-lashed the valves,the timing,when I can measure it has been about 10-12 BTDC,not perfect but close enough for now...please ask me any questions you might need to HELP ME figure out what is going on here...
 Sincerely,
???GT

[Captkaos]

Was the cam a stock grind?  If not, that will probably add to your problems.  Have you modified the PROM to work with all the changes?  Any changes to an ECM controlled system will require some sort of reprogramming.

[GT1000000]

Crane Compu-Cam, Designed to work with this system...Hypertech chip,also for this application...
GT

[VileZambonie]

If it's not setting any DTC's double check your valve adjustment. If you put roller rockers remember zero lash not like steel rocker arms.

[GT1000000]

Latest update, Figured out the fuel pressure too high... lowered to 13.5, from about 16 psi...according to crane[they recommend 13.5]. Something that has been bugging me...the MAP sensor reads 4.88v@ zero rpm and 30 In HG. Shouldn't it be the other way around? Close to zero volts and zero Vacuum at zero RPMs???
Still trying to figure this mess out...Thanks for the help so far...
PS. According to Crane, the roller rockers get zero lash plus 1/2 to 3/4 turn...
Later,gt.

[DnStClr]

GT- my $.02-
The map readout sounds right- the 4.88 volts is a reference signal that's generated by the sensor and it goes to the ecm. Somewhere around 5 volts is correct. The ecm sees the 4.88 volts and returns a signal.
 Zero rpm, of course, shows that the ecm does not see the engine running.
 30 in Hg indicates total vacuum- it's the reference signal by the ecm showing that there is no pressure detected by the map sensor. And that's correct too,    because your engine isn't running and there's 0 pressure being built up in the manifold where the sensor gets it's reading from. So it stands to reason that when there is no pressure, the ecm sees total vacuum .
 Now Vilezamboni will see this and put us straight... . Hope you get it running soon

[VileZambonie]

With the engine idling Map voltage should read somewhere around 1.25 volts but if the engine isn't idling it won't read correctly. Pop the vacuum hose off of the EGR valve and make sure the egr is closed.

[VileZambonie]

Also with roller rockers zero lash is good + may cause the valve to open so adjust them very carefully. The use of a dial indicator and a leakdown gauge can help you set them just right.

[GT1000000]

Sorry,forgot to mention, EGR non-existent,goes back to when I first dropped the crate engine  and installed the Holley pro-jection intake, and I could not track down an EGR that would fit so it has been running without one for over 7 years... As for the zero lash, I will try that... Thanks for clarifying the bit about the MAP...and yeah,briefly,after the engine starts..the scanner reads the MAP voltage somewhere about 1.88-2.33V and about 13-17 IN.HG. Thanks for the input, keep 'em coming...next chance I get to mess with it is Monday,so a list of stuff to check,recheck and double check would suit me just fine...as a matter of fact if the problem persists I may be looking at replacing the TBI/CCC system with a intake,Holley,and a cd box for the ignition. Any ideas in that regard would also be appreciated...
Later,gt

[GT1000000]

Well,here goes,
Relashed the valves to Zero, No noticable improvement, runs a few seconds,shuts off,with the MAP connected,cannot rev up engine...sputters,miisses and dies...
Disconnect the MAP, hard to start, can rev almost as much as I want, Sounds Good and strong  , But reaches a moment when it just shuts down...Almost seems like something electrical or electronic???
The only time any DTC's is when I physically disconnect any sensor,otherwise ECM seems to be functioning normally...
Feeling Quite Dumb and Numb,gt.

[GT1000000]

one more update...After checking and rechecking everything I found what I thought was the answer... the distributor was one tooth off...made the necessary correction and now,with the MAP unplugged,it starts eventually, and seems to run just fine as long as it stays well above 1200 rpm...as soon as I let it fall below that...it almost seems like it is going to idle, but then speeds up just a little bit and cuts off...
At my wits end,almost ready for a gallon of gas and a match,gt.

[VileZambonie]

Did you set the timing? Put the EST in bypass and set it to 0°

[GT1000000]

Cannot keep it running long enough at idle to make that setting...gt.

[GT1000000]

With a liittle help from an extra pair of hands and eyes, I was able to start it with the timing light at the ready and...Yes, with the EST unplugged I got it set to between 0 and 2 degrees before TDC, I would imagine thats close enough for now, but I still CANNOT get this crazy thing to idle...My Head Feels Like Ghost Rider's...gt.

[red4wd]

Is the throttle body sealing off to the intake?  My truck acted like that and I changed the gasket on the throttle body and it is running fine.