fj62 w/ lt1 police interceptor - merged

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Apr 16, 2007
62 w/ lt1 interceptor

Hello to all cruiser heads:
I was turned on to this site to find answers to all my questions by Mike G.
You people are so nice!
I have a 1988 fj62 with a 1996 caprice lt1, attached to a 700r4.
It runs like crap.
I can work on all the toyota parts of this, but have no idea about fuel injection or the auto tranny.
Is this the right tranny engine combo?
How do the o2 sensors work?
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Welcome to MUD!

Could you define "runs like crap"? When is the last time you did a tune up on it? The O2 sensor will cause your engine check light to come on. I don't know if it will actually cause it to run bad. I an carburated though.
Hello to all cruiser heads:

You people are so nice!

Welcome :flipoff2:
You are allowed to change your opinion at any time.
once a cruiser head, always a cruiser head!
I am not exactly sure how to define "runs like ****"
but today I took it for drive down my street with 3" of mud and 6" of snow and it barly had any power under 3k rpm. then it would scream, then put.
I changed the plugs and wires, that is about it. What else? oil and filter of corse
get a code reader and see if it's throwing any codes. check that MAF sensor is clean (little wires). check for fuel lines near exhaust. properly sealing gas cap? there are a million of em.
the more specific you can get, the better.

oh and welcome :flipoff2:
Ok so I am brand new to this, and have no idea how to use this site?
anyways. I bought a 1988 fj62 from some kid .
It has a caprice lt1 with a 700r4. is this the right trans?
It likes to run, but really choppy.
I was thinking o2 sensors.
got an opinion.
cruise on!:beer: :beer: :beer:
properly sealing gas cap? interesting. sorry I posted another Q
LT1s came only with 4L60E trannies. They are essentially the same as a 700R4 but more controlled by computer. They are excellent trannies with low first gears and great overdrive. As far as choppiness goes, I would put a scanner on it and check all readings. Pre 95 LT1s are less problematic with O2 sensors because of there emmisions ratings, but that doesn't mean you don't have issues with them. Just because there is not a check engine light coming on, it doesn't mean that everything is OK.
The O2 sensor if bad will sometimes tell the motor you don't have enough oxygen and sometimes it will tell the motor there is extra oxygen.

My minitruck had a melted O2 sensor wire and I could be driving down the road and it was like Bang my truck would just get a huge boost of power and then other times it would just bog down like climbing a huge hill while I was on flat ground.

The 700R4 is fine. Any GM shop should be able to diagnose the problem(s).

However, you have no idea whether the conversion was done properly until you get it checked out. There are lots of "shortcuts" that would make it difficult, however.
Was the truck yours when the conversion was done? Is it a dog down low and a screamer at the top end? Maybe its got a lopey ass cam in it.
The LT1 seems to be getting more common as a donor motor, what manual transmissions are popular for this? Also what price can someone expect to pay for this motor, are they comparable to a 350 or 302? Also are these aluminum block and head or cast? Sorry for going off topic a bit but it seems like the fellas that know this motor have been in this thread.
The Caprice LT-1 is a cast iron block and head combo.
It was found in a variety of commercial applications, Buick Roadmaster wagons and of course the interceptors.
I have one from a tow package Caprice with the 4L60E transmission.
This application has a manual fan and additional cooling capacity for the transmission.

There are a number of vendors who can reprogram the computer, remove extra wiring and features in the ECM for simplicity.

Your problem may be realted to the VSS(vehicle speed sensor), the Optispark system(GM's cam driven distributor) or a variety of error codes which ONLY a system reader can give the information from these problem areas.

Without anymore true information, all we can do is support you here on the interweb and help with pointers. is a local to me reprogrammer with great credentials.

Until you can locate and isolate the problems, your costs may be tremndously high to solve these issues.

I have an HP book and rebuilding and repairing these great motors and it did shed a huge amount of light on the innards of this engine.

Good Luck


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