I have a tpi 305 1988 and the speedometer and odometer do not work. Does anyone know steps or anything to narrow down the cause? Once I get the cluster out I can lube the cable but is there a way to tell if it's a cable, speedometer head, vss, issue? Thanks in advance, these forums have saved me tons so far.

 

https://www.thirdgen.org/forums/inte...eedo-woes.html

JamesC

 

And I'm going to guess that since my Speedo doesn't work and scan tool shows 0mph at any speed, that is why my cruise control probably doesn't work.

 

I believe yours has an electronic speedo. Look at the driver's side tailshaft of the transmission to confirm.

 

The make/model would be helpful. If the car is a Camaro, the speedo is cable driven. If a 'Bird the speedo is probably electronic.

BTW, Shakenblake, if you wish to add your car's details (car, engine, trans, etc,), go to User CP at the top left of the page, click it, then click edit details and you can update as you see fit.

Best of luck with your issues,

JamesC

 

I forget some times this isn't a camaro only forum thanks for the info it is a camaro

 

Does anyone know what models, Camaro and Firebird, came with a mechanical 140/145 mph speedometer?
Or was it an export only option?

 

1985: All 85 mph
1986: 85 mph on all Camaros, except late year Z28s with TPI, which had 145 mph
1987: 145 mph on Z28s/IROCS with TPI, both 305s and 350s
1988/89: 145 mph on IROCs with TPI, both 305s and 350s

I'm not a Pontiac kinda guy, so I could easily be wrong, but I don't believe 'Birds were equipped with mechanically driven 140s.

JamesC

 

The reason I asked is because I picked to a 140/145 mechanical speedometer off of ebay for my 84 Trans Am. Brand new in the box. It was listed as for export cars.

 

I got the new cable in after making sure driven gear was in good shape. (All stock 700r4 305 like 110ish mph speed) anyways after installing new cable the guage and cruise works!!!!!! But at like 8mph I'm readin 11mph on the guage and at 30mph im reading 40 and at 40 im reading 50. My tripometer didn't seems to start working but oh well. Scan tool confirms the pcm getting the inaccurate info. So I did re lube cable. I'm guessing my issue is in my speedo head? Thoughts, fixes?

 

Sounds like you have the wrong speedo gears in it... something like, your rear end has 3.42s in it but you have the speedo gears for 2.73s. Nothing real complicated.

The fix is, install the right speedo gears to match your rear end ratio.

I think the Firebirds had mech speedo 84-back and electronic 85-up, but don't take my word for it.

It was against the law for a speedo in the US to indicate above 85 mph in a car for sale to the general public, for many years from the early 70s to the mid 80s. It was part of the national 55 mph speed limit. Hence the "export" and "police" versions that went to 140 or the like. The law was repealed sometime in 85 if memory serves.