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1988 2.5L Auto Throttle Body Replacement by slickster
Started on: 03-02-2017 11:29 PM
Replies: 6 (440 views)
Last post by: slickster on 03-06-2017 11:46 PM
slickster
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Report this Post03-02-2017 11:29 PM Click Here to See the Profile for slicksterSend a Private Message to slicksterEdit/Delete MessageReply w/QuoteDirect Link to This Post
According to the interchanges, the only throttle bodies compatible with the 87-88 4 cylinder Fiero's are as follows:

Buick Skylark '87 2.5L
Buick Somerset '87 2.5L
Olds Calais '87 2.5L
Pontiac Grand Am '87 2.5L

Does anyone know if later models such as an 88-91 will work?
Also, I have seen some 700 TBI's listed as for manual transmission only.
Is there a diference between the throttle body for an auto v standard transmission?

Thanks!

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Report this Post03-03-2017 03:19 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
Why do you need one?
You can rebuild/repair w/ a kit and common tools.
See my Cave, 700 TBI

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slickster
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Report this Post03-03-2017 10:46 AM Click Here to See the Profile for slicksterSend a Private Message to slicksterEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hi Ogre,

I already reviewed your page before I posted.

I posted here several years ago about a hard restart when hot problem and have replaced all sensors, iac, coil packs, crank sensor, fuel pump, relays, thermostat, vacuum lines, charcoal canister, computer, updated prom for this issue, fuel pump, plugs, wires, injector, unplugged tcc, installed a cooling fan, insulated the fuel lines, and possibly a couple other things I may not recall off the top of my head.

No codes. Acts like vapor lock. If I open trunk and remove air filter cover for 4 or 5 minutes it will eventually start and run again.

Starts and runs fine on cold starts. Never stalls while running even when it's 90 degrees outside.

Only thing I haven't replaced is the throttle body itself.

I know the throttle shaft has some wear because when I spray starting fluid around outside of shaft the rpms change.

That's why I want to find out whether a later model 700 TBI will work and if there is a difference between these units for automatics and standards.

Thanks!

[This message has been edited by slickster (edited 03-03-2017).]

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Report this Post03-03-2017 09:11 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
TBI etc are make to take some wear in throttle shaft like IAC just allows a bit less air to control engine idle.
You already replace injector and many others... changing TBI is unlikely to help.

get a new/rebuilt or a used ECM?
Used ECM can have same problems, more so the Fiero w/ insulation problem in my cave.

Have you test injector circuit w/ a noid light? It tells you fast if ECM inject circuit is working.
Iffy ECM/PCM often has problems w/ inject drive circuit(s). Example: The inject "transistors" get too hot and blow or crack solder joints. bad joints can cause odd problem or dead completely.(Solder joint problems are why many have blue dingy thingy problems.)
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Report this Post03-06-2017 11:39 AM Click Here to See the Profile for slicksterSend a Private Message to slicksterEdit/Delete MessageReply w/QuoteDirect Link to This Post
I bought the car in 1996 with 128k miles. It now has 156k. In 2000 the ECM failed and stranded me with a flashing check engine light. Towed it to the Pontiac dealership and they put in a new ECM. Car drove fine for a few years, then this problem started. Car has been in storage for past 10 years. I have tried the previously listed remedies over the years without success. There are no codes. I found a TSB that seemed to describe this problem and it listed an updated PROM, which I installed but didn't help. I even wrapped the fuel lines. I drive it every 3 or 4 months (about 500 miles a year) and change the fluids to maintain it. All of the replacement parts are OEM from the dealership. Car always starts right up when I get it out to drive. This problem only happens after driving for more than 15 to 20 minutes on a hot day, then letting it sit for 15 to 30 minutes before restarting. It will then turn over and stall, several times, before eventually turning over and then runs normally. I even removed the console to let the A/C blow on it directly on the ECM but that didn't help. I guess I can drive the car on a hot day, park it, wait 15 minutes, open the trunk, remove the air cleaner cover, install a noid light, then try to start the car and see if the noid lights up - but removing the air cleaner cover is also one of the things I do to get it to start if I'm in a hurry anyhow. The only thing I can think of that hasn't been replaced is the throttle body. The 30 year old junk yard ones that I have seen look like junk and are $60. I have seen new 88-91 700 TBI units for less than $100. That's why I asked if any of these would work. Thanks.

[This message has been edited by slickster (edited 03-06-2017).]

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Report this Post03-06-2017 11:02 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
New GM ECM can have same problem.
IOW ECM is dying from heat and not turning on injector.
noid light will confirm this.
https://www.youtube.com/watch?v=5MmR-wXddVw
AZ might have kits in loaner tools. I think gm pfi noid shown fits 700 injector. don't force it and wreck the plug. If needed try others that might fit better.

Turn key off kills injector power then plug in noid and watch while someone bumps the starter. 10-20 sec max.

700 TBI will often last 200,000-300,000 miles, even more.
Mine is 220,000+ but I needed a regulator diaphragm @ ~120,000. Car ran but started to leak.
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Report this Post03-06-2017 11:46 PM Click Here to See the Profile for slicksterSend a Private Message to slicksterEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks, I will try the noid light when we get some 80+ degree weather here in Ohio.

But I am still curious - does anyone know whether or not a 88-91 Grand Am / Calais / Skylark / Somerset 700 TBI will work in a 88 Fiero and if not why?
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