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Would someone verify location of the OD relay for the 84 4+3? FSM shows location behind the right wheel well but I can’t locate it there. There are two relays on the firewall next to the brake booster one of which is the fuel pump relay but the other one doesn’t match wire colors for the OD according to my FSM schematic. I’ve searched the forum and there is conflicting information on the location… some stating the firewall and some the right rear wheel liner. Any help appreciated.
Thanks Tom
User 'conniekalitta' is the most recent '84 owner thats been through rather intensive '84 OD diagnostics. Maybe reach out to him directly. I don't see where he's mentioned location but here's a thread where it's been discussed.
Thanks @WVZR-1 I’ll give him a shout. I read through his whole thread and gleaned a ton of good information to troubleshoot my intermittent overdrive. He replaced his relay so he will certainly know it’s location. Cheers!
Tom
I've replied to your PM, but one of those relays near the firewall will be your OD relay. OD and fuel pump relays are the exact same (good foresight by GM...), the only difference between them that I can see is that the fuel pump has a six-wire harness while the trusty OD has just five wires.
If the relay isn't your problem, it will almost certainly be something that I had touched on during my endeavors with this tricky system as well. I'll keep my eye on the forum in case you need additional help.
(Or maybe IHBD will chime in too... he helped me massively during my time with the OD issues.)
@VikingTrad3r thanks for the suggestion, you hit the nail on the head. Although the switch looked clean it was intermittent during a continuity check. Cleaned as suggested and took it for a drive, engaged every time so looks like that can be checked off on the list of issues remaining on this car. Interesting your photo shows the relay exactly as they are on my car but my FSM state’s different. I’ve attached a few photos in case someone else stumbles across looking for the same thing. On a side note, not sure why so many people have their hate on these CFI Vettes, considering the 80’s technology this car is a blast to drive. Really enjoying it more and more as I work out the kinks from sitting for the last 20 years.
appreciate the assist.
The image in post #5 is from a later C4 FSM - your 'snippet' of 8A-29 'COMPONENT LOCATION' is the only line of the text that doesn't reference an Image Figure reference. For anyone that would like maybe a more definitive image:
The image in post #5 is from a later C4 FSM - your 'snippet' of 8A-29 'COMPONENT LOCATION' is the only line of the text that doesn't reference an Image Figure reference. For anyone that would like maybe a more definitive image:
the “snippet” was provided to show the incorrect location in my FSM. Highly probable the same thing will happen to someone else…
On a side note, not sure why so many people have their hate on these CFI Vettes, considering the 80’s technology this car is a blast to drive. Really enjoying it more and more as I work out the kinks from sitting for the last 20 years.
appreciate the assist.
As they say, hindsight is always 20/20 and looking back, the Crossfire cars are terribly unimpressive when compared to the Tuned Port L98 ones just a year later. The L98 then went on to be among the most reliable Gen 1 small blocks (at least from what I’ve heard). I personally don’t like it because it looks like an enormous facehugger. The sleek futuristic crossfire air cleaner cover is just beautiful in comparison.
Since you were in the Navy, think of the 84 Corvette like the F-14A Tomcat from back in the day. Extremely impressive platform with an outdated engine design that gave it an ugly reputation. Then the 85-91 cars are like the F-14B. More reliability and more power. But hey, nothing like Z51 cornering in the 84. Stiff as rocks.
Not to stray too far off topic... My personal experiences have been I'm always fighting the TPI cars to run correctly while the CFI just worked. I attest that to the CFI is more forgiving to seeming fine when it's not and not being as refined even when it top shape. The TBI injectors are insanely robust when left to sit compared to the TPI ones which is typically what has given me issues until the TPI has been updated. Beyond that, vacuum leaks on the TPI have been an issue no matter how many torque sequences I followed. Although I'd argue there are more leak points on a CFI and it being more prone to them. That being said... beyond those differences... they have about the same number of failure points. Despite the power difference I always liked the feel of the CFI a little better, it felt like the power was more evenly distributed probably because there was less of it.
TPI has a better engine management system in stock configuration and the benefit of head and camshaft improvements over its production cycle as you get to the later years.
glad you got your overdrive sorted out. Back on topic.
As they say, hindsight is always 20/20 and looking back, the Crossfire cars are terribly unimpressive when compared to the Tuned Port L98 ones just a year later. The L98 then went on to be among the most reliable Gen 1 small blocks (at least from what I’ve heard). I personally don’t like it because it looks like an enormous facehugger. The sleek futuristic crossfire air cleaner cover is just beautiful in comparison.
Since you were in the Navy, think of the 84 Corvette like the F-14A Tomcat from back in the day. Extremely impressive platform with an outdated engine design that gave it an ugly reputation. Then the 85-91 cars are like the F-14B. More reliability and more power. But hey, nothing like Z51 cornering in the 84. Stiff as rocks.
you are officially the first person ive heard who has said they dislike the looks of a tpi! ive heard the facehugger reference before but never the dislike of the aesthetics. interesting. imo the lt5 and l98 are gorgeous.
you are officially the first person ive heard who has said they dislike the looks of a tpi! ive heard the facehugger reference before but never the dislike of the aesthetics. interesting. imo the lt5 and l98 are gorgeous.
Weirdly enough, I don't like the look of the L98 but I love the LT5 look. It just looks very "present" if you catch my drift. If you pass by one at a car meet, the huge intake, big "4 CAM 32 VALVE" text, and big cam covers just scream at you (the same way I like the "CROSS-FIRE INJECTION" text on the 84 air cleaner). The L98 looks decently cool but it looks empty. Can't quite explain it.
When I look at an "old" engine, I consider the historical significance, and what efforts and conditions have prevailed that the example I'm looking at is still in existence at all.
84 Overdrive Relay Location
