starter interference '83 vs. '87
#16
Instructor
I just went to the same hell you are going through on my 1988 924s. I tried the bosch sr62x but the wiring would not match up. I went to Oreilly 's auto parts and bought the Ultima R712321A. It was listed for an 1982 porsche 924 turbo(old style fat starter). Installed it and the problem is solved. I have had zero problems with it. This is a very frustrating problem. I broke the nose off of 3 of the skinny starters. Very expensive problem also. Good luck.
#17
I'm back to this issue, blew up another starter. O'reilly lists R712357b now, is that the same as above? Pelican lists the same starter for all years so that's useless. I want to be sure I'm getting a fatty this time.
https://www.oreillyauto.com/shop/b/c.../924?q=Starter
https://www.oreillyauto.com/shop/b/c.../924?q=Starter
#18
Nordschleife Master
Are you sure you have the correct bellhousing on your engine? Could the po have put a turbo bellhousing instead of an na?
Turbo and na starters are the same and the bellhousings look identical, will physically swap over and the starters will look like they fit fine and will both turn the engine over. However the starter on each is positioned differently due to the na riding on 130 gear teeth and the turbo on 132 gear teeth.
So, if your bellhousing is wrong the starter teeth will not quite mesh correctly, it will turn and start likely with a jolt or two but the starter gear life will be vastly reduced.
Turbo and na starters are the same and the bellhousings look identical, will physically swap over and the starters will look like they fit fine and will both turn the engine over. However the starter on each is positioned differently due to the na riding on 130 gear teeth and the turbo on 132 gear teeth.
So, if your bellhousing is wrong the starter teeth will not quite mesh correctly, it will turn and start likely with a jolt or two but the starter gear life will be vastly reduced.
#19
I doubt the bell housing is a turbo, the engine is from an '83 944, the car is an '87 924s. I now think the fuel pressure regulator is leaking into the vacuum line causing starting issues and kick back, I ordered a new FPR and I also need a new starter, again, I just want the right one, I may have had the right one all along, I don't know but it see it's listed as for a 924s and late model 944 so it likely HASN'T been the fatty
#20
Rennlist Member
I doubt the bell housing is a turbo, the engine is from an '83 944, the car is an '87 924s. I now think the fuel pressure regulator is leaking into the vacuum line causing starting issues and kick back, I ordered a new FPR and I also need a new starter, again, I just want the right one, I may have had the right one all along, I don't know but it see it's listed as for a 924s and late model 944 so it likely HASN'T been the fatty
Plenty of folks have had leaky FPR's and leaky injectors, etc., without blowing up starters, and yours probably hasn't been leaking for years, so I wouldn't check the box on finding your solution until time proves you right. Could be as simple as cheap rebuilds, but I'd make quadruple sure your bellhousing and starter ring gear are compatible. As for starter kick-back based on errant speed/ref sensor pulses, I'd point out the early DMEs used a different conditioning circuit for those sensor pulses. Was that circuit as good as the dedicated chip they developed for the later DME's? I don't know... But if you have an '83 DME, it's one thing to consider, along with ensuring the wiring harness from the sensors to the DME is in very good shape. Those are internally shielded cables, and they are a known failure point on these cars.
Last edited by Tom M'Guinn; 04-19-2019 at 04:39 PM.
#21
okay, I'm learning, I'll try to get at the bell housing numbers with a camera or something
http://forums.pelicanparts.com/porsc...fferences.html
I suppose I can count teeth on the ring gear, someone has been in there with a very heavy hand so anything is possible, could be mismatched flywheel/bell housing as you say. They swapped the engine at some point, I can't imagine an '87 924s ended up with '83 944 block, non turbo bell housing but a turbo ring gear??, or standard ring gear and a turbo bell housing, but well, who knows. I will investigate this.
http://forums.pelicanparts.com/porsc...fferences.html
I suppose I can count teeth on the ring gear, someone has been in there with a very heavy hand so anything is possible, could be mismatched flywheel/bell housing as you say. They swapped the engine at some point, I can't imagine an '87 924s ended up with '83 944 block, non turbo bell housing but a turbo ring gear??, or standard ring gear and a turbo bell housing, but well, who knows. I will investigate this.
#22
Rennlist Member
On that pelican post, beware that lots of cast parts have a casting number that are different from the actual/official Porsche part number. That probably explains the confusion on that thread and serves as a warning against using those numbers to identify what part you have...
#23
ordered another starter, "supposed" to be the pre '85 944 version. I also pulled the plugs, fuel fouled, badly, standing fuel in the cylinders, FPR maybe? Maybe related? Off to recheck FPR tests, I think I have to jumper a relay to trigger the pump and see if the FPR's vac line is dumping fuel
#24
I thought I posted a while ago, don't see it. New starter arrived, it's the older version so that's good. Installed and she fired right up. Here's some pictures of the later model, the smaller one, for post '85 944 and the bigger one for pre '85. Supposedly the fat one is one you want, less susceptible to kickback. Most vendor's don't differentiate so I searched multiple vendors until I found one (partsgeek) that reported different numbers for early 944 and later. I bought the one that came up for early 944 and it arrived as the fatter one. Hopefully it's the magic bullet.
nose totally blown off this "later" starter, the smaller diameter one
body is smaller, about 2 3/4" diameter, this is the "later" starter, we have destroyed three of these
early starter, 3.75" diameter
early on top, later below
early on top, later below
nose totally blown off this "later" starter, the smaller diameter one
body is smaller, about 2 3/4" diameter, this is the "later" starter, we have destroyed three of these
early starter, 3.75" diameter
early on top, later below
early on top, later below
Last edited by jvandyke; 04-30-2019 at 09:40 AM.
#25
I swear I posted this earlier too, oh well. I did a fuel line test, FPR and injectors all check out fine. As above, the fatty starter seems (only one start so far) to work great. Weather sucks around here but the car will come out this weekend and hopefully we're good to go. Fixed odometer and redid all gauge lighting this winter, very anxious to drive the thing.