DIY_EFI Digest Wednesday, October 13 1999 Volume 04 : Number 578 In this issue: Chrysler IC's in ECU Re: DIY_EFI Digest V4 #577 Re: DIY_EFI Digest V4 #576 See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Wed, 13 Oct 1999 11:29:24 -0500 From: "Rob Maxon" Subject: Chrysler IC's in ECU >I have a 85 Chrysler K-car, I looking for information on the IC's that are >in the ECU > The IC's are : Motorola SC88352CP CPU (= 6803u4) Motorola SC87313CP Port Expander ? ?? +B8432 RAM ? (=is probably Z22 see below) ?? 4289473 driver IC's (=is probably Z51 see below) If its got a sticker covering a window, its a 2764A eprom. Some 1985's had (2) 28 pin 2764A eproms at Z51 and Z22, while others had one 28 pin 2764A eprom at Z51, and one 24 pin (I think) rom chip that I am not sure about at Z22. These are the 2 chips at the opposite end of the board from the connectors. They are labeled Z51 and Z22 on the board, I think.. Rob 86 GLHS #048 >Any info about mid 80's chrysler ECU internal workings will be helpfull. I >see alot about Ford and GM, but nothing yet on Chrysler. >Please respond to JECFL98@xxx.com ------------------------------ Date: Wed, 13 Oct 1999 12:47:22 -0400 (EDT) From: William T Wilson Subject: Re: DIY_EFI Digest V4 #577 On Wed, 13 Oct 1999, DIY_EFI Digest wrote: > My friend has an RX-7 (early '90s pretty much standard equipped I > believe) which is running fairly rich. I haven't looked at > it yet but I'm going to help him troubleshoot it later this week. Does > mazada use a similar system to GM? Im thinking it's pretty different .. I don't know too much about the GM motors, but I can say a (very) little bit about the Mazda... The Turbo II ECU is pretty much a modern EFI controller. There is an oxygen sensor, which is used at low rpm and part throttle. At higher speeds or full throttle, the ECU switches over to fuel maps. The ECU also controls the wastegate via (I believe) vacuum activation in order to regulate boost. The ECU has fuel maps up to very high boost levels, but does not use most of them as there is a fuel cut at around 8 psi of boost. The rotariness of the motor doesn't really affect the ECU very much. If the engine is running rich only at idle, there are a number of simple adjustments to correct that. If the engine is running rich at full throttle, it's probably supposed to - the turbo models do run fairly rich in order to prevent knock. The rich running at other conditions is very possibly a bad O2 sensor, or it could be something else. but it probably isn't the ECU failing as they are quite sturdy. How do you know the engine is running rich? It could be, for example, a plugged catalytic converter, which can cause similar symptoms... ------------------------------ Date: Wed, 13 Oct 1999 18:41:28 +0100 From: Ade + Lamb Chop Subject: Re: DIY_EFI Digest V4 #576 At 15:00 12/10/99 -0400, you wrote: >>FWIW the rover mini system is a MEMS system... >what ever that means. > >"Modular Engine Management System". >In principle the same ECU is fitted to every post-Lucas era 'MEMS' >controlled Rover engined vehicle model (Honda engined versions use Jap >electronics); that includes Mini, 200, 400, 600(turbo only) 800 and MGF. >There obviously need to be variations due to engine spec - capacity, TBI or >multi-point inj., ignition type - distributor or distributorless, turbo or >nat-asp., etc. This is where the 'Modular' bit comes in; the ECU is >fundamentally based on the same internals with various different hardware >configurations and programs to accomodate the different sensors and >actuators required for each individual application. >You will come across a few different 'version' designators; eg. MEMS1.3, >MEMS1.6, MEMS1.9 which roughly segregate the applications. >All MEMS systems use as a minimum the following sensors: >Additional sensors , depending on application, include: >Knock What does the knock sensor do? What does it mean if I don't have one >Fuel rail temperature Why? >All MEMS systems control ignition, either single coil or distributorless. >All systems use a stepper motor controlled throttle stop for idle speed >control. Apart from the Mpi (97 on) minis which have a bypass valve which bleeds are from the filter casing into the manifold. >Hope this is of interest. It is, thanks, Ade ------------------------------ End of DIY_EFI Digest V4 #578 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".