Stumped (Page 2/6)
jelly2m8 JUL 11, 03:03 AM
As mentioned you need to test fuel pressure. Ogre posted the fuel pressure specs.

You mentioned someone replaced the fuel pump, alot of people replace the pulsator with the supplied piece of hose to connect the pump to the sending unit. For some reason aftermarket pumps have a piece of un-proper non-submersible hose and it will deteriorate and split causing fuel pressure issues.

Put a fuel pressure gauge on it, with the engine running find the rubber return line on the right side over by the battery and with a pair of needle nose pliers BRIEFLY pinch it closed while watching the gauge. This will 'deadhead' the pump and force it to pump at max capacity. You should see around 30 PSI pressure. Again only do that briefly and see if the Fuel pressure gauge spikes. If it does, the pump and everything the tank is most likely ok, if it does not ( the pressure will most likely drop) then something is wrong inside the tank. The return line, not the pressure line.

[This message has been edited by jelly2m8 (edited 07-11-2024).]

jelly2m8 JUL 11, 03:09 AM
Worst thing anyone can do with any car with starting / running / dying issues is to NOT confirm proper fuel pressure and spark first.
82-T/A [At Work] JUL 11, 08:27 AM

quote
Originally posted by Gizmo0816:

Oh and also when I started the car with the reader in it was not happy, engine sounded like crap and stalled out. Is that normal?




NM, responded super late, there are like 5 replies since, and I forgot you had an 87.

[This message has been edited by 82-T/A [At Work] (edited 07-11-2024).]

82-T/A [At Work] JUL 11, 08:32 AM

quote
Originally posted by theogre:

If have any or all of those, buy a "rebuild" kit w/ all soft parts including the reg diaphragm.




For Gizmo0816, I highly recommend doing this. These TBI units have a bunch of gaskets, small and large, and they do tend to get "crusty" over the years. It's a good idea to order the rebuild kit (it's like $45 bucks) and completely disassemble it, spray it down with brake & parts cleaner, and then reassemble with all new gaskets. If you are going to keep this engine (it's a very decent engine, being an 88... e.g., balance shaft, DIS, roller cam, etc.), then I recommend replacing and / or having the injector professionally cleaned (I think they're also like $40 bucks on Rock Auto).

The only thing is... just make sure you've replaced the fuel filter first. You don't want to further gum up a cleaned / new injector.

[This message has been edited by 82-T/A [At Work] (edited 07-11-2024).]

theogre JUL 11, 08:35 AM
⚠️ Warning: F-pressure gauges don't work @ low pressure like 9-13psi.
see adapter page bottom.
Gizmo0816 JUL 11, 12:02 PM

quote
Originally posted by 82-T/A [At Work]:
NM, responded super late, there are like 5 replies since, and I forgot you had an 87.




It's an 88 I might've mistyped
82-T/A [At Work] JUL 11, 12:05 PM

quote
Originally posted by Gizmo0816:
It's an 88 I might've mistyped



Nah, it was me... sorry.
Gizmo0816 JUL 11, 12:14 PM

quote
Originally posted by 82-T/A [At Work]:
For Gizmo0816, I highly recommend doing this. These TBI units have a bunch of gaskets, small and large, and they do tend to get "crusty" over the years. It's a good idea to order the rebuild kit (it's like $45 bucks) and completely disassemble it, spray it down with brake & parts cleaner, and then reassemble with all new gaskets. If you are going to keep this engine (it's a very decent engine, being an 88... e.g., balance shaft, DIS, roller cam, etc.), then I recommend replacing and / or having the injector professionally cleaned (I think they're also like $40 bucks on Rock Auto).

The only thing is... just make sure you've replaced the fuel filter first. You don't want to further gum up a cleaned / new injector.



Yeah I'll do this some gasket that I have seen on the car aren't in good shape so I'm only left to assume that the ones I can't see are just as bad.

I'll also get the stuff for the fuel pressure test.
It already has a new fuel filter and injector, would I want to replace the injector with the old one so it isn't exposed to brake cleaner? Old one works well enough, just replaced it because I figured the filter wasn't any good.
Gizmo0816 JUL 11, 12:18 PM

quote
Originally posted by theogre:

If By "reader" means jump ALDL A & B... nothing should be damage.
ECM may try shutting off IAC port because think trying to set main idle stop. See cave idle stop.

ECM Scanner don't care but may keep Idle @ 1000RPM while connected because ECM is "running 2 threads" & isn't made for this. See cave, ECM section.

700 TBI can leak in several ways... Top 3... (See cave 700 TBI)
Vac leak @ bottom where mounted &/or side ports.
Vac/air leak when 2 TBI sections meet.
Fuel Leak @ the regulator. Look w/ air cleaner cover off w/ engine running.

If have any or all of those, buy a "rebuild" kit w/ all soft parts including the reg diaphragm.



Alright thanks, and it is like in the shape of an obd2 reader, but all it does is jump the pins. Just a little bit safer than a paperclip or a jump wire.

That makes me feel better tho that 2 people said it shouldn't harm anything. On other forums, not about fieros, they were saying all sorts of stuff.
82-T/A [At Work] JUL 11, 12:23 PM

quote
Originally posted by Gizmo0816:

Yeah I'll do this some gasket that I have seen on the car aren't in good shape so I'm only left to assume that the ones I can't see are just as bad.

I'll also get the stuff for the fuel pressure test.
It already has a new fuel filter and injector, would I want to replace the injector with the old one so it isn't exposed to brake cleaner? Old one works well enough, just replaced it because I figured the filter wasn't any good.



Well, I would keep the old injector as a spare, but if you just bought a new injector... then you're fine. I don't expect that rebuilding the TBI unit will solve all your problems, but it will give you an opportunity to clean the entire thing (all the EGR gasses as well) and ensure that when it's rebuilt, it's running in top shape.

I didn't see above, but definitely get a service manual for your year. You can download them for free from a few places (not legal of course), but I prefer to have the book in my hand and be able to flip through it. You can get that from http://www.themotorbookstore.com. People laugh, but I also like to have the Haynes repair manual. Always rely on the specs in the service manual above the Haynes, but often times the Haynes will provide a different perspective / picture / diagram that's perhaps not done as well in the service manual.

Shameless plug, my daughter is also restoring her 85 Fiero 2m4 SE. Slightly older version of your engine (doesn't have DIS ignition), but a lot of the things still apply, and it might be of some help to you (particularly in some of the upgrades for the Iron Duke, etc.): https://www.youtube.com/@GenerationZGarage


Anyway, it's a really cool car. If you can get it running well, you'll have a ton of fun. It's not a racecar by any means, with the Iron Duke that is... but it's a really fun car that you can push hard when you've got that engine running well. I had (still have) a V6 version of that car (87 SE V6) and man... that was a blast when I was growing up. I drove that thing like crazy, and it was quick for its time too.