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[RobertH]

Hi everybody, my 91 XR2 started acting up with this weird problem the other day. It starts and runs great first thing in the morning or when it has sat for a few hours. But after driving it, shutting it off, then starting it again within an hour, it sputters like it has an exhaust leak. It idles fine, and shows no indication that it wants to die, but it's noisy as hell when I accelerate. In the morning, it's like it never happened. Also, yesterday while I was driving it like that, the CEL flickered on and off a couple times. Has anyone experienced this? What should I be looking for? Thank you in advance!

[tonlaw71]

If you're running the stock air box, check that articulated tube that runs from the air box to the j-pipe on the turbo. There could be cracks that manifest themselves under acceleration.

[RobertH]

I'll check that out, thanks! Is that something that also wouldn't manifest until the car warmed up?

[NomakeWan]

I had a 280Z that had a cracked MAF hose and a cracked PCV hose. I don't buy that it'd be the cause of an intermittent problem only when warm, but I do buy that it may crop up while boosting. The material in the hose would expand slightly when hot, so if anything the problem should be worse when cold.

Sadly I can't think of something that would cause the issue. You say it only happens if you start the car warm? So it's not just when the car warms up, but after you've turned it off? Is there any chance you could get a video of this phenomenon? If it truly only happens on warm starts and not during continuous running, that's a very important fact that rules out a lot of potential causes.

[RobertH]

It is definitely on warm starts. When I start it cold, I can drive it all over town with no issues, until I stop somewhere. Then it starts acting up when I get back in and start it back up.

[Rocketman]

Have you tried pulling codes to see what is up? That might be able to send us in the right direction

[RobertH]

I actually just got home to do that. I'm getting one long flash followed by 7 short flashes. It keeps twisting that code, nothing else.

[NomakeWan]

Funny, I just got a Code 17 myself today, though mine was because I had temporarily opened my BPV to atmosphere and thus the mixture was completely wrong. So rather than the O2 sensor being faulty, it was likely correctly reading the incorrect A/F and throwing the code. In your case I'd normally say that the heat is causing your O2 sensor to screw up, throwing off the mixture...except that you say your car drives perfectly fine until you shut it off, which is what's throwing me for a loop here. It means there shouldn't be something mechanical wrong--because then your car would start driving awful once it heats up regardless--and that this is more likely something electrical or electronic.

For a list of codes with descriptions: http://www.roadraceengineering.com/323gtxtech/gtxdiagnostics.htm

[RobertH]

Thank you for the info! I'll try to troubleshoot it, and let you all know if I find anything. If anyone where has experienced this before, your input will be appreciated!

[RobertH]

Update: I thought I had traced the issue to the oxygen sensor, but no such luck. What I did discover is that cylinder 4 is not firing when I start the car warm. I pulled that plug, and noticed that the ground electrode was white and the ceramic insulation had what look like brown burn stains. I'm going to try changing the plugs and see what happens. Could wires be an issue as well?

[WashiestSnake]

Could wires be an issue as well?

The plug wires definetily can be a issue, if they havent been changed in awhile I would do them. Afterall it should be like $100 max for a set, for all you know that might be your solution. If its not the plugs my bet would be the distributor, but this has no signs of that being failed.

[NomakeWan]

If an entire cylinder was not firing, that would explain your Code 17.

However, generally heat-based problems would affect you while the car was still running, and wouldn't rely on shutting it off and turning it back on again. That's the part that's really confusing me. If your wires/plugs are bad, they should be bad all the time, or at the least become bad while driving and heating up. They shouldn't magically become bad just because you stopped and started again.

Worth it to replace them all if you haven't done it, however, just as preventative maintenance. Same with the cap and rotor. Easy, fairly inexpensive insurance.

[SHOwn]

I bought my 7mm Taylor wires at RockAuto for $15 and about $7 for delivery. I have a similar issue. My XR2 acts flooded when starting after a short run to the store and a 15 minute shopping time. It starts and coughs and stumbles and often dies. When restarting, it acts flooded. It did not do this before the tune up which included the wires and NGK G-power plugs gapped at .23. I'm considering widening the gap. Otherwise it is fine. It runs starts and idles fine when you floor it to clear the flooding. Always starts great when cold or fully hot.

[RobertH]

Oddly enough, changing the plugs seemed to eliminate the problem. The plugs looked like they had some age on them, and I've only had the car a few months. They also didn't seem like they were torqued in at all. They were barely finger tight, and the gap was somewhere near .40. Gonna pay attention to it, and hope for the best.

[NomakeWan]

.040 (I assume is what you meant) seems pretty wide for an XR2. I read the 323 GTX guys run .032, and go even down to .028~.030 on higher boost. However, the service manual from Ford does say that .039 is correct for all Capris, so I guess YMMV.