Anybody have a 1989 R factory manual covering 454? 89 454 owners?

[Grim-Reaper]

Anyone know of an online manual?

Does 89 454's have air injection?

When stone cold does it high idle over 1500RPM?

My 88 start up manners are pissing me off. The 88 454 starts up and idles 1800 RPM dumping huge amounts of fuel trying to get the cat hot real quick. My Cat doesn't get hot ever (its under the work bench). I'm sick of this on 30 degree mornings. Its brutal on the cold engine and its wasting a LOT of fuel.

I have a 89 ECM and I want to see the pin out to make sure it all matches up before jamming it in..

 

[thatK30guy]

Hey Eric! Long time no see around here. How ya been? Missed you on this site for a few years now. Gonna start coming back now?

As for your 454 problem, don't know what to tell ya. Sorry on that and hope someone can figure it out for you.

 

[Grim-Reaper]

I peak in every once in a while to see what new and give a wave.

Tossing around a idea for a home Brew bastard offspring of a Chalet and a Burb. If the right 6.2 3/4 ton 4x4 barn door burb shows up when I have cash who knows.

Right now enjoying the 24mpg of the 4Runner and crying when I fill the 454 Burb.

Trying to figure out if its even possible to get 15mpg out of the burb. Starting to look like an exercise in futility or not being a good Cost verses result deal.


Thinking about doing a 4 inch drop and bagging it to clean up the airflow. See if a 700R4 can live behind the 454 since I am just not coming up with a cheap Gear vendors after years of looking.

 

[5280k5]

I've got a '90 454 TBI and it does the same thing, high idle until the coolant temp. increases. Alldata lists '89 as having AIR injection but that doesn't necessarily mean they all had them You could probably mess with the coolant temp sensor that feeds the ecm so it thinks it warmer than it really is but may make for hard starting b/c the injector pulse will also be affected.
Anyway here's some schematics for 'ya

Some basic info:

Fuel delivery from the injectors (which deliver fuel in all operating modes) is controlled by changing the amount of time the injectors are turned on or "pulsed" by the ECM. The ECM checks the Coolant Temperature Sensor (CTS), Throttle Position Sensor (TPS), and the crank signal, and determines the proper air/fuel ratio for starting. This ranges from 1.5:1 at -36°C (-33°F) to 14.7:1 at 94°C (201°F).

When the engine is first started, and engine speed is above 400 rpm, the system goes into OPEN LOOP operation. In OPEN LOOP, the ECM ignores the signal from the oxygen sensor, and calculates the air/fuel ratio based on inputs from the coolant temperature and Manifold Absolute Pressure (MAP) sensors

 

[Grim-Reaper]

As high as 1800 RPM? Its like nails on a chalkboard to me hearing that stone cold motor got to 1800 RPM.

That sucks. I wonder if it can be corrected with a custom prom?

My membership is expired so I can't view the attachments. Can you e-mail them to me at "offroadk5 At msn" or post them to something like photobucket?

Thanks.

 

[dyeager535]

As long as its not a hardware issue (hot fuel module bad? I don't know anything about those) then it could be cured with a PROM change. tbichips.com...

 

[Grim-Reaper]

Dorian:

It appears intentional. The warmer it is the lower the the RPM. 30f its fires up tachs to 1800 RPM then idles down after a minute or two. at 80F it may only tach up to 1200-1300 and then idle back down.

This is also a really bass ackwards set up. The Air injection is only pumping in open loop. As soon as it goes closed loop it diverts. The manual indicates this is normal operation and the high idle and horribly rich condition is an attempt to get the Cat up to operating temp FAST to me emissions requirement.

I was hoping that the 89 ECM was more reserved but 5280k5 90 doing it sounds like not much can be done without a Prom change.

 

[dyeager535]

GM saved money on the truck cats, I don't believe any of them were plumbed for AIR, so vented to atmosphere like you mention. All cars AIR vented to the cat in the situation you mention, to help out functioning.

You gotta love emissions regulations, burn lots of gas quickly so later on you can have less pollution. Doesn't quite make sense to me.

That's why I suggested tbichips.com. Brian can probably tell you if that was as intentional (as it sounds) but if that's your only problem, I would think it to be a pretty cheap "fix". Can't hurt emissions I imagine, since if you DO get tested, it's not with a cold engine.