Just bought a 91 b4c. Working on the engine (new edelbrock hi flow intake) and finding strange things like 24# blue ford injectors. Want to see if there is a chip installed. Where do I look and what do I look for?
Thanks

 

under the kickpanel on the passenger side you got the ECM, take it down and open the little top and see if there is a stock prom or a custom in there.

 

Thanks. When I take the top off how do I know if its stock or not. And not to sound ignorant what exacley does PROM mean?? Not used to this terminology.

 

PROM (Programmable Read-Only Memory) is the CHIP , the correct name for it is MEMCAL or EPROM (Erasable Programmable Read-Only Memory)

And if it looks like this (my car 1989, stock MEMCAL in place) :


and if it chipped it MAY look something like this :


It could also be a reburned MEMCAL and then it looks the same.
So if you want, take a picture if it (clear) so I can se the numbers and post it here and ill help you out .

 

Ok......Makes sense now. Thanks alot for explaning that to me. I pulled the computer out and removed the panel and heres what I found.


It does not look stock. I cant get my POS digital to take a good enough pic to get the number clear. Here is what they say:
under barcode along top of chip: *973159104331351*

On silver tag on chip itself: AVJP
1615
1348

Sure be nice to know exacley what im dealing with here. Tere is a tag on the outside of the silver box housing the chip as well......let me know if those would help or not.
Appricate it!
Gordon

 

What year is the car ?
Cant find the AVJP. Looks like a stock prom, but modell and year would help alot

 

Its a 91 rs B4C x-texas dps police car. Was a 305 till the previous owner had engine work done to bump it up to a 350. Those are all the numbers I can see.

 

The chip code (or BCC) is AUJP, the way GM prints the labels makes U's look like V's.

That is the latest L98 w/auto MEMCAL.

On the paper tag on the ECM look for a Service No. Most likely will be 1227730. But may be a newer number.

RBob.

 

Rbob,
Your correct, my service number matches that.
My car has a 5 speed std trans in it. Does that matter on the programing?
Is that program for a 350 or 305?
So many things to figure out not knowing exacley what you have.
Thanks for the input.
Gordon

 

AUJP is for a 350 engine.
I thought of AUJP but I wanted him to dubbelcheck the prom number

and its a Auto tranny prom not an manual 5 speed... So the memcal dosent seem like stock if you have a manual 5speed and its AUJP thats for autotranny.
The 350 never came with manual tranny, only auto.

 

As for using an auto calibration with a stick tranny, as long as startup, decel and driveability are OK, then use it. Along with decel is stalling issues. Stalling is important, so if it doesn't want to stall then all is OK.

There are y-body L98 w/6-spd transmission calibrations you could use. But they can have other issues.

Using AUJP is the closest you can get to a stock f-body calibration for a 350 and stick tranny.

RBob.

 

Ok, that answers what I needed. Car runs great with no stalling issues or anything. Idle seemed high so I backed the screw off a bit and it idles down most of the time but still runs high sometimes.
Thanks alot for the help.

 

There is a difference in SA between AT and MT to.
Also you got TCC solenoid and much more controlls in the AUJP (for 350 with Autotranny).

 

Ok......Just this week got car put back together with new intake and rails. I now have a few more issues. Seems lately for each one I fix 3 more arise. Please help if you can.....

1. What should the base timimg be with the programming we have figured out I am running within the previous posts. I need to adjust it now that I have everything back together but with that program where do I set it? Belive its showing 8deg Btdc right now.

2. I have a stalling issue. Hoping its timing related. when I run down the road all is well but when I pull up for the stop sign, rpm;s dip to 500 then up to 1000 then down to 400 then up to 1000 then stalls. up down up down up stall.

3. I have adjusted the idle screw on the new throttle body. had it set earlier to iulde right at 900. Now after a drive, it wont idle smoothely. irratic 700 to 1100 intermittat. New ngk plugs today. Issue was there with the autolite doub platnums too.

4. When car is hot after 20 min or so drive, and dies due to the not idleing issue it drags whan cranking over. Did it when I bought the car, put on a new starter and went away. 3 weeks later now after my work on the engine its back. Cant be another starter can it??? Makes you thing its noit going to start it drags down so low. Maybe timing related too?

5. I posted this in another forum but no replys. My new throttle body only opens 1/2 way at wot. Gas petal all the way pasted to the floor throttle butterflies only 1/2 way. Wont I get more power with them wide open? Why wont they open all the way with the petal all the eay down? Can I adjust this?

Thanks for the help guys.

Will check back later.

 

can yall explain to me where the ecm is located? i cant find it and i want to install a chip. and do any of yall now if the jet chip 6 pac is any good? thats the one i wanna get.

 

On the passengerside above the feets you see this cover:


Remove the bolts and it will look like this:


Then you unscrew this bolt:


Then the ECM will drop down (be carefull so the wires dont get damaged):


Then remove this 2 bolts:


Then it will look like this:


Depending of what type of chip you bought the install process may be different:


I burned my own proms so I do it like this:


And back in place:


hope that helped you out.
And please dont use my pictures without asking me first

cheers

 

thanks alot that was really helpful. i hope you didnt take those pics just cause i asked though. tanks again!!!!!!!!!!

 

No problems, just glad it helped you

I got alot of projects under my homepage : http://irocz.info.se/
Been doing pretty much, and I always take detailed pictures and put on my page to show others

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