tbi issues, on my 88 gmt400

[89Suburban]

Stick a vacuum gauge on that thing and see if it does any talking. Run a ground wire to a screw driver and check all the spark plug wires for leaks. I can send the '89 throttle body out if you want to try that, it's ready to plug and play and worked fine, hasn't been tampered with. Wish I was there to help.

 

[Swims350]

never know, but as for valves yea I adjusted them awhile back and they were fine before cleaning the tbi. Nothing changed during the tbi rebuild, just redid it, cleaned the injectors, replaced the sending unit and inspected all th elines and hoses, blowed them completely clear while it was apart. Timing was never changed or anything else since it ran fine before rebuild then ran like crap after.

I have yet to try the icm which is next and maybe add a few degrees timing to see what happens, other then that I'm not going to change injectors or the esc module unless I find decent known working used ones to try, I'll just switch to carb setup.

 

[RetroC10Sport]

I'm ready to run 4.3 or 5.0 injectors in mine to stop it from running rich.

 

[Swims350]

I have ran a vac. gauge and it as fine but may ned to again.

as for the tb 89 if you want man that'd work I can try it out. or maybe even injectors or something.

like I said before whatever won't work or doesn't fix it I'll just ship it back to ya and if I go carb everything back your way, and if I do find something that fixes it then we can discuss that part more.

so if ya got er man and aint using er send it out if ya can one day, same address and all.

 

[89Suburban]

Ok, send those parts back and I will swap out dawg.

 

[Jims86]

I'm ready to run 4.3 or 5.0 injectors in mine to stop it from running rich.

You'll throw those 350 injectors back in faster than you took em out.
Have you plugged the valve covers(pcv ports) and filled the crank case via the dipstick tube with propane yet?
Chris, I had to replace a couple of those acorn rocker nuts last time, because they were'nt binding enough to keep from backing off.

 

[RetroC10Sport]

It has no vacuum leaks, no exhaust leaks, nearly every sensor is new as well as EGR, tried 3 sets of 5.7 injectors, new FPR, only thing that hasn't been replaced was the ECM.

 

[Jims86]

It has no vacuum leaks, no exhaust leaks, nearly every sensor is new as well as EGR, tried 3 sets of 5.7 injectors, new FPR, only thing that hasn't been replaced was the ECM.

So you have done the intake?

 

[RetroC10Sport]

I have, yes.

 

[Jims86]

I have, yes.

hmmmmm, Well....the only other thing that comes to mind is if the EGR pintle is seating or not.
Edit...Never mind.
Maybe try the Capacitor thingy before shelling out for an ECM.

 

[RetroC10Sport]

A used ECM is only $15.

 

[Jims86]

A used ECM is only $15.

Capacitors are $1 each...and there is no guarentee that the next ecm does'nt have the same issue. seems to be a widespread problem...even with mine, except with TPI, BLMs stuck to 128, NEVER moved, and the INT stayed really close to it.

 

[89Suburban]

Jim can you do that capacitor mod?

 

[RetroC10Sport]

Well, I have a shitload of caps around, got a link to what to do?

 

[Jims86]

Jim can you do that capacitor mod?

Well, I have a shitload of caps around, got a link to what to do?

I dont remember if its this thread or not, but it has the part numbers for the rad shack capacitors, and you install one on each injector plug, betwix the power and ecm wires...basically jumping them with the capacitor. I wouldnt do it internal on the ECM.